Rapid Diagnosis RT PCR - " a transforming moment"
More emails from Dr Breeze
"Fortunately, we were able to take the devices and test system into the field in Uruguay in November 2001, where they performed splendidly on farm in a remote area...." The statement made by Roger Breeze of USDA to the Royal Society Enquiry (pdf) November 10 2008 ~ Rapid test for C. difficile infection gets EU go-ahead. And for animal diseases...?
C. difficile is resistant to most antibiotics. There are roughly 58,000 detected C. difficile cases in the UK each year, and the number of deaths rose by around 55 percent to 8,500 in England and Wales in 2007. The virulent Type 027 strain of C.difficile has been reported in 16 European countries. C. difficile infections are estimated to cost the NHS up to £8,000 pounds per patient and more than £200 million each year. Now Cepheid has launched its molecular diagnostic test as a European CE IVD Mark product under the European Directive on In Vitro Diagnostic Medical Devices.
"European hospitals will have access to a reliable, rapid test for Clostridium difficile, which simultaneously detects and identifies the commonly occurring strains and specifically identifies the more virulent Type 027 strain. The new 50-minute test runs on Cepheid's GeneXpert(R) System.." Cepheid
The GeneXpert(R) System is "a closed, self-contained, fully-integrated and automated platform that represents a paradigm shift in the automation of molecular analysis, producing accurate results in a timely manner with minimal risk of contamination".
Such a system can also, with the appropriate reagents, detect such animal diseases as Foot and Mouth before the onset of clinical signs. The 2001USDA test, offered to the UK for field testing in 2001 detected the presence of FMD virus in experimentally infected cattle, sheep and pigs before clinical signs of disease were detectable. It took about 60 minutes. Sample preparation was minimal. The offer was turned down by Professor David King and his colleagues.
That was seven years ago.
Had such available kits been used in 2001 and 2007 to detect which animals really were infected there would have been no unnecessary culling with all the attendant trauma and financial loss. News that such systems are also validated in Europe for early pre-clinical-sign diagnosis of virulent animal disease is surely long overdue.August 18 2008 ~ Can the EU really - possibly - not know that such a small portable machine has been in existence for years?
According to the BBC website, the EU is to fund a £2.3 million project to develop a diagnostic machine for H5N1. UK experts have called for a national surveillance programme to detect H5N1 cases in Indonesians and Dr Alan McNally, from Nottingham Trent University, "believes his technology could make a difference."
However, Dr Roger Breeze tells us that the Indonesian government and US Department of Defense Global Emerging Infections Surveillance System (GEISS) have already been monitoring, detecting and responding to avian influenza H5N1 in Indonesia for several years. GEISS uses PCR devices in labs and also the Idaho Technology RAPID for portable field detection.August 18 2008 ~"... It has been possible and practical to use the RAPID device to detect avian influenza virus on farm and in the field since 2000."
Dr Breeze recently visited the laboratory at Kamphaeng et, in northwest Thailand, operated by the Royal Thai Army and the US Defense Department and his email, complete with links, explains that when Indonesian patients are PCR positive (the hospital lab returns results within 2 hours), a mobile team then travels to the affected village to examine and test others with just such a portable RT-PCR kit as the EU now declares it "hopes" to develop.
"... I asked the lab director if the results of PCR tests performed in the village were regarded by public health authorities with the same validity as those conducted in the lab itself. She replied,"Of course. It is the same people performing the test in both places using the same controls, test reagents and equipment. Why would we not treat them identically?"
The EU, says the BBC, "hopes to come up with a version of the machine that can fit within a briefcase" Dr Breeze points out that the RAPID, in use now for several years, "is sold in a small suitcase".... Read in fullApril 2008 ~ Svanova Biotech launches rapid test for FMDV
The press release
ý".. The test has been developed in co-operation with the OIE Community Reference Laboratory for FMD, Institute for Animal Health, Pirbright Laboratory, UK and Instituto Zooprofilattico Sperimentale della Lombardia e dell´Emilia Romagna (IZSLER), Italy, as part of the EU project Lab-On-Site, a project on new and emerging technologies for detection of important diseases in animals and animal products....The SVANODIP® FMDV-Ag is a simple direct test for the detection of all seven serotypes of the FMDV antigen in swab and tissue samples. It is a rapid test, which may be carried out on the field, next to the animal. It may be used for early detection of infection, as first line diagnostics in order to control the spreading of infection. The test procedure is rapid and simple, providing a result within 10 minutes."
(This is a test for antigen.)December 2007 ~ "......The issue is whether that test should be done on the farm or in a fixed lab,
See extract from email from Roger Breeze
"... If you detect FMD on farm within minutes - versus days in sending a sample to a lab - you will save enormous amounts of money in response costs downstream. If a farmer had the choice between paying 12 dollars for a test versus seeing his animals killed without testing because they were located within 3 miles of an FMD infected farm, all the farmers I know would be happy to pay for a daily test out of their own pockets. .... If there was an outbreak in the US, we could be testing herds. You would pool samples from several animals in a herd - not test each animal separately. Consider the cost of killing those herds that were not infected in Britain recently - was that a bargain compared to $12? I expect the cassette cost for the simple device will also be $12 to $15. There is an old saying that if you think education is expensive then try ignorance. ...."
Read in fullSeptember 21 2007 ~ "We can now add DEFRA to the list of those who never miss an opportunity to miss an opportunity"
writes Roger Breeze in this article for warmwell today: (Dr Breeze's team has successfully set up rapid on-site testing in former Soviet Bloc countries.)
"..... In 2002 Callahan and colleagues (1) described a real time PCR test that could be performed within an hour on or close to premises where there were animals that might be infected... This test was more sensitive than traditional foot and mouth virus isolation and had the added advantage of detecting virus in non- optimal samples in which the virus was dead and not detectable at all by cell culture.
Read full article The conclusion that wilful ignorance has been displayed at the top of DEFRA seems inescapable.
But Callahan and his colleagues also demonstrated something remarkable and previously unsuspected - that this PCR test could detect foot and mouth infected animals 2 or 3 days before they showed any outward signs of disease and before virus could be identified by any other means.
Had this rapid PCR test been performed on a few nasal swabs collected from each farm examined by animal health officers in Surrey in recent weeks there is no question but that infections would have been detected long ago even though lesions were not recognized.
The British veterinary authorities and the government's Chief Scientist, David King, have known about this technology since 2001 - ......
I also read that the Countess of Mar was told in the House of Lords that "tests have to be validated by the OIE"... This is not true....."August 10/13 ~ " the laboratory must move into the field and test animals quickly before irreversible actions are taken." ProMed
'ProMED' means 'Program for Monitoring Emerging Diseases' and is the Internet-based reporting programme of the International Society for Infectious Diseases (ISID). The moderators are international experts in their field who screen, review, and investigate reports before posting to the network. ProMED-mail is independent and free of political constraints. To read on ProMed that diagnostic testing should now be "out of the laboratory" is very cheering. On Saturday, a ProMED moderator, in the course of a five paragraph comment about the UK situation, (www.promedmail.org)wrote:
"....In the past -- that is, pre-1980 -- when we killed "contact" herds it was not questioned and laboratory techniques then could not have handled the volumes of samples. Today all that is different and thousands of samples are run each day. This brings home the point that the laboratory must move into the field and test animals quickly before irreversible actions are taken..."
(More) For six years warmwell and others have been asking that the analysis of samples should happen at the place where samples are actually taken rather than be taken by car, train or air to the reference laboratory. Results can now be obtained in the field within minutes rather than hours and days, can detect FMDv before the onset of clinical diseaseAugust 2007 ~ " the case for a humane, civilised and scientifically sound policy has strengthened over the past few years to the point where it is beginning to look unassailable"
Magnus Linklater has kindly sent warmwell his article written for today's Times. He looks back shudderingly to six years ago when the "farming establishment closed ranks against any suggestion that there might be a more humane approach." On the question of vaccination, many readers will share our reaction to this gem:
" I remember asking the government's chief scientist, Sir David King, to explain to me why it was not being considered. "I would need five hours to explain the science to you," he said. "Unfortunately I don't have that time." ...."
But, " Let us not go back there, however. The fact is that there has been, since then, a sea change in attitudes within the Department ....the realisation that the science on which so many of those decisions in 2001 were based, was less sound than we were told..
..Again, there is no point in going back into that debate. What is important now is to record how far science has advanced in the meantime. There are accepted tests which can distinguish between infected and vaccinated animals....We know, too, that FMD "carriers" do not infect other animals... "pen-side" tests .. allow a vet to carry out on-the-spot checks to determine whether a herd of cattle or a flock of sheep have been infected, rather than having to send samples back to a laboratory. Rapid diagnosis of this kind means that biosecurity measures can be imposed immediately rather having to wait for the results of tests.
... vaccination can begin within that area as soon as it is available ...
.... I cannot, hand on heart, say that the battle for the vaccine has been won. There are still those in Defra and elsewhere, who will argue for slaughter as the only effective response to this disease. But the case for a humane, civilised and scientifically sound policy has strengthened over the past few years to the point where it is beginning to look unassailable..." Read in full (or on Times website)August 7/8 2007 ~ A prototype on-site rapid diagnostic machine is being used in Surrey
A very impressed Bryn Wayt has sent this email to many contacts. "... a very nice and helpful lady vet and phoned and confirmed that, "a prototype RT-PCR unit had been used on the first IP, and the VO on the second site would be using it." His email is worth reading in full. We feel the manufacturer is irrelevant - as long as rapid test results can be obtained before the long wait for lab confirmation. It appears that Pirbright has been doing quite a bit behind the scenes with portable devices. (UPDATE Pirbright's portable machines are not performing RT-PCR it seems but the very good news is that the whole portable PCR field will be transformed with very cheap machines that are highly automated within the year, according to a reliable source. )
We find this news exciting - but once again, it has to be teased out and we are very grateful indeed both to those who ask the searching questions - and those who give the answers.12/ 13 June 2007 ~Rapid diagnosis via automated multiplexing platform: "we have always known that the platform's flexibility confers benefit in other markets, such as veterinary diagnostics and the monitoring of bioterror threats such as foot and mouth"
A news release ( Thanks for news of this link to FMD News - a service provided by the FMD Surveillance and Modeling Laboratory, University of California at Davis ) from Nanogen, Inc reports on new funding and "collaborative agreement" with Canadian agencies which include the Canadian Food Inspection Agency (CFIA)
".... The purpose of the funding and collaborative agreement is to develop diagnostic tools for the detection of natural or potential bioterror threats to livestock, such as foot and mouth disease and avian flu, employing the company's NanoChip® platform ... The NanoChip® 400 is the company's second generation automated multiplexing platform....the system provides a simple, fast and cost effective means for performing molecular testing.."
March 20 2007 ~ "the main device under discussion at the meeting is a $1,000 mobile test system and reader the size of a small portable television"
Animal health experts from 15 nations, including the UK, are meeting today to discuss rapid diagnosis technology. The conference, The Early and Rapid Diagnosis of Transboundary Animal Diseases: Phase I- Avian Influenza is taking place in Vienna and is part of a $500,000 coordinated research project run jointly by the FAO and the International Atomic Energy Agency ( www-naweb.iaea.org/nafa). The project aims later to field-test devices, identify areas where the kits can be used first and explore sources of funding.
John Crowther of the Joint FAO/IAEA Programme's Animal Production and Health section points out:"The genius here is that such mobile testers can be used by anyone, with the most basic training. Even farmers could do a test and the result could immediately be processed back to a central point, like a mobile phone message. Within two years, such tests could revolutionize disease diagnosis. Ultimately the tests would be done locally by people in their own countries, making schemes much more efficient in everything including speed, costs and local knowledge."
See more at www.un.org/apps/news/story
( It was in 2001 that Professor Fred Brown first argued for the UK to field trial such a device. As it was, with neither vaccination nor on-site diagnosis, carnage by computer, ruthlessly enforced, was the result of the UK's inability to pinpoint where the disease really was.)February 25 2007 ~ Rapid Diagnosis for flu in birds: Multiplex test
From the latest report of the USDA/ARS Research Project: Development and Validation of Rapid Diagnostic Tests for Avian Influenza and Newcastle Disease
".....We have also developed an internal control to be run as a multiplex test with both the AIV and NDV tests to assure that the RRT-PCR reaction was performed correctly. The internal control should help to eliminate false-negatives. We have also developed hemagglutinin subtyping tests for most of the 16 described subtypes of AI. We remain active in the evaluation of primer sets to assure they work well with outbreak viruses from around the world. Finally, the development of dried down reagents to aid in the stability of the reagents, increased quality control, and ease of use of the test has already developed interest from a number of different diagnostic laboratories. The Southeast Poultry Research Laboratory (SEPRL) has been on the leading edge of use of real time PCR testing as a diagnostic test for viral pathogens of poultry with its work on avian influenza virus and Newcastle disease virus. Through collaborations with APHIS, the rapid diagnostic test for avian influenza and Newcastle Disease was validated and adopted by APHIS ...."
January 26-28 2007 ~ Silence on validation
Readers of warmwell may share our bafflement about how the grail of validation is to be achieved, especially for the rapid diagnosis on-site technology for foot and mouth. Pirbright's rapid diagnostic strip test device for FMD was discussed at the 2000 conference in Bulgaria, but, after 7 years, there are no signs that it is to be used in the field - or even "considered". As for the ARS machine, offered to the UK and used successfully in Uruguay in the same year as our disaster, the US GAO ( Government Accountability Office) paper, Homeland Security: Much Is Being Done to Protect Agriculture from a Terrorist Attack, but Important Challenges Remain GAO 2005: contained lines which were on the advice of the former Associate Administrator for Special Research Programs at USDA's Agricultural Research Service
".... Importantly, the tools can detect disease before the animal shows clinical signs of infection...... rapid diagnostic tools would not only allow for a rapid diagnosis but would also permit the monitoring of nearby herds before symptoms appeared so that only infected herds would have to be killed......rapid diagnostic tools would be helpful because FMD would be detected in less than an hour, informed control measures could be implemented, and herds in the area would be under regular surveillance."
But rapid diagnosis in the field seems as far away as ever. In 2005, when the Countess of Mar was told: "tests have to be validated by the OIE. We are waiting on that" her frustration was evident. " My Lords, it is coming up to five years since the foot and mouth disease outbreak. If that has not been done, can the Minister say why not? I remember the late Fred Brown coming over from America and telling us that they were using the tests in America. Why has that not been done in this country in the past five years?
It is now over six.
A RAPID PCR machine (www.idahotech.com) costs about £40,000 pounds and the tests for exotic diseases like foot and mouth, classical swine fever, avian influenza, and Newcastle disease cost about £ 3 pounds each. Of course, with other test reagents, this same machine can detect all the common animal diseases too (with the exception of BSE and scrapie).
PCR assays were designed to be performed as real time assays outside BSL 3 containment either in a laboratory or on portable devices taken to the site of the problem.
For the latter purpose, there are three machines now available: the RAPID and RAZOR from Idaho Technology Inc. and the Smartcycler om Cepheid Inc (new window). In time, there will be other devices that are cheaper, faster and more robust. But all will share the same characteristics. Assays will be performed by persons of limited training (soldiers, technicians); assays will be performed using quality-controlled standardized reagents and protocols that are internationally consistent; results will be obtained in an hour or less; assays will be reviewed over the Internet as they take place by technical experts located at distant sites; and detection results will flow into an Internet-based Command and Control systemExtract from Dr Roger Breeze's letter to warmwell Jan 2006
"As you know from my papers, I believe the PCR offers a transforming moment for FMD control by which one can monitor all the herds in an area continuously and only slaughter those where there is infection (and I believe in vaccination immediately also).... Many FMD viruses representative of all 7 serotypes were genetically sequenced by Dan Rock's team at Plum Island and the sequence information was transmitted electronically to Tetracore in Maryland. Rock and Tetracore worked together to compare the complete sequences of many different viruses simultaneously to find regions of the sequence that were identical between all the different viruses - these common regions would be targets for PCR tests. Tetracore have some proprietary software that eases this comparison.
Having identified likely targets, Tetracore made reagents to these targets and Rock tested these with real viruses at Plum Island. From this, the ARS Tetracore FMD PCR test was developed, and this did not require any materials that had ever been in contact with live viruses....
.... What happened with the FMD and other PCR tests is that "validation" became a smokescreen to preserve monopoly and jobs. And as was demonstrated by California, all the waffle from those insisting on "further validation" and federal not state responsibility disappears out the window when the fire starts in their own homes.
Currently, I understand that the ARS Tetracore FMD PCR test is very close to approval by USDA and OIE, a matter of months I hear." Read in full
March 2006 ~ On 13 March, a field laboratory with real-time polymerase chain reaction (RT-PCR) capacity to detect influenza A/H5 virus, was established by the US Navy Medical Research Unit 3 (NAMRU-3), Cairo (Egypt), at the Anti-Plague Station (APS) in Baku.
March 22 2006 ~ Cepheid's GeneXpert is the world's only system to combine sample preparation with real time PCR (polymerase chain reaction) amplification and detection
-......answers from unprocessed samples in minutes. ..... No specialized facilities or highly skilled laboratory training is required to operate the GeneXpert System "Cepheid (Nasdaq: CPHD), a broad-based molecular diagnostics company, announced today that it has received both certification and designation of the GeneXpert(R) technology as Qualified Anti-terrorism Technology (QATT). GeneXpert is now listed among products approved by the Department of Homeland Security and is granted coverage under the Support Anti-Terrorism by Fostering Effective Technology Act known as the SAFETY Act..."
See also background materialAbout rapid diagnosis tests
PCR for Foot and Mouth - click here
On-site use of tools such as these is critical to speeding diagnosis, containing the disease, and minimizing the number of animals that need to be slaughtered.
Communications from and by Dr Roger Breeze, formerly of Plum Island
Rapid PCR and Bovine TB Control in Great Britain See the " Paper for Discussion " by the National Beef Association (page 10 of pdf file)PCR (Polymerase Chain Reaction)
There are two forms of using this powerful technique by which an enzyme and a cycle of heating and cooling is used to generate billions of copies of segments of DNA (to make detection and spoligotyping easier). After multiplication, the system identifies TB, or any other bacteria, or virus or DNA material by comparison with a known sample, utilising the properties of florescent light to do so.a. Laboratory-based conventional heating block thermocycler using agra gel electrophosesis; this has greatly facilitated research in the Badger Road Traffic Accident study.
b. A portable mini-lab which can give an on-the-spot diagnosis of infection within 30 minutes; this technique has been developed for detection of biological warfare agents on the battlefield in the US, and in this country by the Defence Science and Technology Laboratory. In the UK it is being "spun-out" by an offshoot of the MOD, Enigma Diagnostics, with investment led by Porton Capital, and including the Treasury and a private venture company, Partnerships UK, and was announced in the veterinary press in September. I
A variant of this system in the form of a machine called a Lightcycler, was recommended by Professor Fred Brown of the US Plum Island Animal Disease Research Center in 2001 to the UK Government to rapidly diagnose Foot and Mouth on site. One individual went as far as ordering one, at a cost of #20,000, but the Government intervened to prevent this without providing the industry or even the individual with an explanation.
See also Veterinary Times 27th Sept '04 "Battlefield technology deployed in fight against bovine TB" and BBC News 4th Oct '04
The obvious potential of a portable PCR cycler machine is to give a rapid identification of TB and the spoligotype of TB present in badgers. If one animal from a sett is found to have TB of a type causing infection in nearby cattle, then that sett could be treated with carbon monoxide with less nervousness by Ministers who would be able to give a better explanation to the general public.There are 29 strains or spoligotypes of bovine TB, of which 17 are found very infrequently. In the UK the most common is type 9 with type 11 being more common in Devon, type 21 and 9 more common in Somerset and Dorset, and Cornwall being higher in types 9 and 15. The geographical distribution of spoligotypes of bovine TB in badgers has a high level of correlation with the distribution of spoligotypes in cattle. Spoligotype 35 has recently been identified in farmed deer near Ulverston, Cumbria, and linked to a spread to cattle there. The samples for multiplication in the PCR machine can be from any source and could merely be from a small amount of cattle blood or badger sputum or urine. Samples from several animals can be put in each of the glass testing tubes within the machine. A single case of infection in one animal would show up, allowing immediate rechecking of the animals in that batch.
The suitability of the portable PCR cycler machine for testing cattle for TB obviously depends on finding cattle that are shedding TB bacilli - either in milk, saliva, dung or urine - or which have bacilli in their blood.
The potential advantages of the PCR cycler over the gamma interferon test is that it should be able to differentiate between bovine TB and avian TB in blood and can be used on farm and give a result within 30 minutes. In the case of cattle this would save the wait of 3 days to read the skin test and the further wait of 6 to 12 weeks for confirmation of TB by culture test.
However the PCR cycle seems potentially to be of even more use in identifying bovine TB in badgers - which no other test can currently do satisfactorily. The sensitivity of the current (brock) ELISA blood test for badgers is only 40.7 per cent, and needs to be done 3 times at 28 to 42 day intervals, which entails keeping wild badgers in captivity for at least 84 days for a result. I
A further attraction of using this PCR technique is that it may be accurate enough to distinguish the TB status of individual badgers within a sett. If a half hour test can reveal this, then the targeted cull of badgers that we propose might be refined even further.
"As we sit here now there are no validated tests and of course were all working hard towards that objective." Professor David King, Chief Scientific Advisor to the UK Government, on the Today programme, December 18 2002
Professor King's careful use of the word "validated" notwithstanding, rapid diagnostic, portable PCR tests, invented in the US in the 1990s and offered to the UK at the start of FMD 2001, are being used around the world and have been for some years. In May 2005, a Canadian team deployed a battery-operated portable PCR machine in Angola to diagnose within four hours which patients were infected with the deadly Marburg virus. Otherwise blood samples would have had to be sent outside the country for testing. That would have taken days if not weeks. The same team used a geographic information mapping system to map the homes and contacts of infected people to direct and speed investigation of potentially-infected contacts. Details at (http://www.cmaj.ca/cgi/content/full/172/11/1430).
These PCR assays were designed to be performed as real time tests outside specialized laboratories like Plum Island on portable PCR machines taken to the site of the problem. Most PCR machines are delicate and suited only to a controlled laboratory environment. But in the 1990s, Idaho Technology Inc. (www.idahotech.com) developed the RAPID, a ruggedized machine that could withstand the rigors of military field deployment to allow pathogen detection on over 30 samples to take place inside a vehicle. The latest version of this machine the hand-portable, 9 lb RAZOR is able to perform the analysis in about 30 minutes in a moving vehicle, since even 30 minutes of immobility makes for a vulnerable target on todays battlefield.
About the RAZOR portable machine
"........allows non-traditional testers such as first responders and other non-laboratory personnel the ability to get valid results quickly. Reagents for the RAZOR are freeze-dried in plastic PathFinder(tm) pouches, which provide increased stability. Reagents can be stored at room temperature and are packaged for rugged shipment. Each sample pouch contains a sampling kit that includes all of the necessary items to perform an analysis of potential class A bio-threats. When preparing the test samples, the liquefied sample is automatically drawn from a syringe by the vacuum in the pouch, which eliminates the need for any measurement or pipetting by the user. This format can also be adjusted-one sample can be tested against multiple pathogens or multiple samples can be tested against a single target in the 12 lanes of the pouch. The freeze-dried reagents are the same as those used on the extensively deployed R.A.P.I.D. system. . ..."
The PCR test identifies a small piece of the genetic material of a virus that is a fingerprint or signature for that virus by labeling this with a chemical that glows under a laser beam.
But viruses are exceedingly tiny and may be present in only small numbers in the sample taken for examination, making detection impossible. So the labeled virus piece is subjected to up to 40 cycles of heating and cooling over a period of about 45 minutes: after each cycle, the number of labeled pieces is doubled. This process involves an enzyme called a polymerase and the number of labeled pieces increases exponentially in a chain reaction: 1 piece becomes 2, 2 become 4, 4 become 8 and so on, so that by 20 cycles there are over 1 million daughters of the original labeled piece. As the number of labeled pieces increases, the glow under laser light becomes visible and is tracked on a computer screen cycle by cycle. Scientists can thus watch the analytical results as they are generated in real time and do not have to wait until the end of the test to learn that a sample is positive"U. S. public health and law enforcement officials .... have had to confront the problem of detecting high-consequence pathogens, outside the comfort of a reference laboratory and have again adopted portable real-time PCR devices as a way to provide fast, accurate answers wherever the pathogen might be present. ..." RAPID ON-SITE DETECTION 2002
Speed is probably the most important advantage of the RRT-PCR technology as results may be obtained within three hours of sample collection, as opposed to virus isolation which takes a minimum of five days.
May 3 2005 "...According to experts, on-site use of these tools is critical to speeding diagnosis, containing the disease, and minimizing the number of animals that need to be slaughtered.
DOD uses rapid diagnostic tools to identify disease agents on the battlefield.." GAO report number GAO-05-214 entitled 'Homeland Security: Much Is Being Done to Protect Agriculture from a Terrorist Attack, but Important Challenges Remain' which was released on March 9, 2005. See http://www.warmwell.com/05may3gao.html
the portable real-time PCR machine, which is now widely deployed
"....The term "real-time" refers to the ability to monitor all stages of the reaction and identification as it proceeds, rather than to have to wait until the end for a result. "Portable" means that the device is taken to the site of the problem and operated there by the military - it is not confined to a central laboratory staffed by trained microbiologists. Recently, as U. S. public health and law enforcement officials have come to realize that these same biological threat agents might be employed against civilian populations, they too have had to confront the problem of detecting high-consequence pathogens, outside the comfort of a reference laboratory and have again adopted portable real-time PCR devices as a way to provide fast, accurate answers wherever the pathogen might be present. ..." RAPID ON-SITE DETECTION OF FOOT AND MOUTH DISEASE VIRUS"On-site detectors should transform disease surveillance and control"
PhD Roger Breeze, BVMS, PhD, MRCVS Centaur Science Group - U.S. Agricultural and Food Security: Who Will Provide the Leadership?
Sept 12 - Sept 18 2004 ~ "It is fair to say that we have taken PCR out of the research lab and into the field where it is most needed."
The Telegraph (Wednesday) carries an article about what it calls the "first DNA-based test that can diagnose a range of diseases within 30 minutes" They refer to the "portable mini-lab" developed at the Defence Science and Technology Laboratory, Dstl, Porton Down which "could eventually cost less than #10 each." Trials are to take place at hospitals in Portsmouth and Liverpool and in-the-field testing for animal diseases, including foot and mouth and bovine TB.
Telegraph "The test could change the face of general practice and veterinary medicine. .... ..... Yesterday, speaking at a conference in Bournemouth, Dr Mullis said tests based on the method had huge potential because "you need to know what a disease is before you can do anything about it".
Can the UK Government continue now to ignore such rapid diagnostic tests in contingency planning for foot and mouth?
At first, Porton Down wanted to find a way to use PCR for fast battlefield detectors of biological warfare agents such as anthrax but its wider potential was realised ...... The team plans to provide two rapid, automated PCR machines for various uses...
...... There will also be in-the-field testing for animal diseases, including foot and mouth or tuberculosis in cattle within 30 minutes, rather than having to send samples to a lab. Tim Rubidge, Dstl head of technology transfer and investments group, said the idea of a tabletop DNA test laboratory was no longer a "a twinkle in the eye of a research scientist looking far out into the future". ..... The Porton team uses custom-built test tubes made from a novel, electrically-conducting polymer to heat and cool samples. This not only speeds up the process, but also creates a lighter, more portable instrument."
March 2 2004 ~ RT-PCR diagnosis against FMD to be tested in Texas.
AgNews "Experimental technology to rapidly detect foot-and-mouth disease will be tested in Texas this spring as the result of an agreement between the U.S. Department of Agriculture and the Texas A&M University College of Veterinary Medicine. The agreement, which also will test classical swine fever, means the Texas A&M researchers will be responsible for testing cattle and hogs with new assays to determine the tests' accuracy in populations of disease-free animals. ....
Currently, foot-and-mouth testing may only be performed at the U.S. Plum Island Animal Disease Center in New York, a high-security biocontainment facility. The usual method of confirming foot-and-mouth includes virus isolation a procedure that, while accurate, may take up to a week to obtain results plus the time required to ship samples to Plum Island. New, rapid tests that could be performed in the field would enable officials to quickly detect and stop massive spread in a disease outbreak, researchers said. ....
The new experimental testing procedures that will be evaluated use "real time" polymerase chain-reaction technology to identify genetic material specific for the viruses that cause foot-and-mouth and classical swine fever. No active foot-and-mouth virus will be used in Texas. "Such procedures can give results in less than one hour and could be modified to test livestock on location during outbreak situations," ...."
(The conference Pan American Health Organization (PAHO), gather in Houston, Texas to "give a final push towards the eradication of foot-and-mouth" tomorrow.)
Feb 25 2004 ~ 80% of all state public health laboratories in the US now have and use SmartCyclers.
It is, as Fred Brown said, "a beautiful piece of kit, simple and not costly" - and making use of it three years ago, as it was used in Uruguay in the same year, would have avoided bloodshed and trauma. The RT-PCR rapid diagnosis kit now used by the Pennsylvania Veterinary Laboratory - ( "in a matter of hours, it can determine both the presence and strain of the disease") is the Smart Cycler . We have confirmation from the journalist who wrote last Sunday's article in the Philadelphia Inquirer that the "new machine" is indeed the same machine that was offered to the UK government by the Agricultural Research Service (ARS) of USDA in early March 2001 for field tests. It is, as we hear from the Cepheid installer, now in 80% of all US state public health laboratories.
As was noted in tactfully phrased evidence to the Royal Society Inquiry (pdf. new window)"Unfortunately, yet understandably, Pirbright staff were too busy coping with the demands of epidemic control to explore new technology during the spring and summer of 2001 . As a result, my offer to provide the latest diagnostic technology was not taken up.
The Philidephia article noted that even with the help of the older, slower Bio-rad machine: ".. the state was able to announce that it had confirmed avian influenza, that the particular strain was virulent in poultry, and that it was unrelated to the type implicated in Thailand and Vietnam. The public was reassured that there was no Asian connection. Agriculture officials knew how big a quarantine was needed, and scientists had crucial details needed to start tracing the source of the infection."
Fortunately, we were able to take the devices and test system into the field in Uruguay in November 2001, where they performed splendidly on farm in a remote area..."
The Smart Cycler, with appropriate reagent, is considerably faster.Even now, three years on, we can find no mention of RT-PCR technology in the141 pages of the latest DEFRA Foot and Mouth Contingency Plan (pdf - slow - new window)
Feb 24 ~" a further indictment of the UK's refusal to recognise and grasp the same opportunity three years ago"
Comment from Alan Beat about the item on the Chinese tests posted on February 14, and which applies equally to the news of the RT-PCR test at the Pennsylvania Veterinary Laboratory :
"This technology is the very same that was offered to the UK authorities in the early stages of the 2001 FMD epidemic by their USA counterparts, and was bluntly refused on the grounds that it was "not validated" by the OIE (just before the contiguous cull, itself unvalidated, was introduced). By appropriate choice of reagent chemicals used, such tests can accurately identify and strain any viral infection, so the Chinese announcement is not in any sense a scientific advance, rather it is the practical application of well-established technology - and a further indictment of the UK's refusal to recognise and grasp the same opportunity three years ago."
"... the real-time PCR assay for foot and mouth disease virus detects all seven FMD virus serotypes
and differentiates this virus from other RNA viruses of animals and man and specifically from three viruses that cause almost identical diseases in livestock, namely swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses. The assay detects as few as 10 virus particles, well below the number required to establish an infection and is more sensitive than cell culture. Significantly, this has been found to be a preclinical test: in experimentally infected cattle, sheep and pigs, foot and mouth virus can be detected 24 to 48 hours before the onset of clinical signs of disease. A single assay costs about £5. ..." See full articleFeb 22 2004 ~ New DNA-based test speeds diagnosis of avian influenza
Philadelphia Inquirer Sunday 22Feb
" ...a new DNA-based test, capable of confirming the disease within hours, has arrived in labs around the region at a fortuitous time. ....About a year ago, the state bought DNA-testing equipment that can identify a virus within 24 hours of collecting the sample. A newer model, with a turnaround of several hours, arrived less than two weeks ago at the Pennsylvania Veterinary Laboratory in Harrisburg.
See also MasterAmp Real-Time RT-PCR Kit (pdf file), an example of the sort of kit now available. We assume that DEFRA has been looking into this new technology fo many months now. We mentioned the Chinese PCR kit on February 14th2004
The staff have yet to be fully trained and validated on the new equipment, but they lost no time running samples from the Lancaster farm on the new machine, known as real-time RT-PCR (reverse transcriptase-polymerase chain reaction). Their findings, confirmed by the National Veterinary Services Laboratories in Ames, Iowa, identified an H2 strain of avian flu - a concern, but not nearly as bad as the type found in Delaware.
A quarantine of the farm and screening of 16 flocks within five miles appear to have contained the infection, said state veterinarian John Enck...."
Jan 9 2003 ~ Rapid Diagnosis PCR tests: a peer-reviewed publication, lab validation, and successful field tests in South America.
Roger Breeze's ProMed posting of May 2001. ...getting on for TWO years ago. Much has moved on since then, including a peer-reviewed publication, lab validation, and successful field tests in South America.
Extract: "These devices offer rapid real-time detection and identification by polymerase chain reaction (PCR) assays, are designed for use on farm at the site of the problem as hand-held or portable units, and communicate real-time data via the Internet to those who need to know in order that immediate action can be taken. ..... The system is specifically intended to support immediate detection on-site by operators with limited training, not just by highly-trained personnel geographically restricted to centralized laboratories. ........ The FMD assay requires minimal sample preparation and results are available in less than 2 hours after collection. The assay detects all 7 FMD virus serotypes and differentiates the virus from near relatives and from swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses. In experimentally-infected animals, FMD virus can be detected well before the onset of clinical signs of disease. ...... instead of taking the sample to the expert in a central laboratory, the system takes the analytical data from the farm to the expert, so that any comment can be immediately returned to the person performing the analysis on the site. The system thus offers a time saving of at least 24 to 48 hours in definitive detection of virus. If time is gained, multiple alternate courses of action become possible for those charged with controlling the disease outbreak. This is the true significance of the system."
"we did attempt to validate Fred Brown's test and it didn't pass the validation"
said Professor David King on the Today Programme (Dec 18 2002) (See transcript below)
But here is an extract of the letter sent as evidence to the Royal Society Enquiry
It was also sent to the Lessons Learned Inquiry and given by hand to Lord Whitty
...Our real time PCR assay for foot and mouth disease (W) has been validated in the laboratory: it has proven to be a pre-clinical test for infection in cattle, swine and sheep, it detects all 7 serotypes of FMD virus and differentiates this infection from other viral diseases that cause similar clinical signs. The test is more sensitive than viral culture and will detect as few as 10 virus particles....
The research paper with these results appeared in the Journal of the American Veterinary Medical Association.
Some eight months after we had disclosed the existence of our x;h/lD test to Dr. Donaldson, we read in the Veterinary Record that the Pirbright Laboratory had subsequently established a relationship with Cepheid and conducted some experiments with FpvfB reagents supplied by that company (data published by Alex Donaldson and others in the Veterinary Record, 2001).
I have no idea what those reagents were because the paper does not describe them. But I can be sure that these reagents were not those developed by USDA-ARS and Tetracore because Cepheid does not have this proprietary information.
I hope there has been no confusion in Britain between the Cepheid mystery test and the real time PCR test developed at Plum Island...."
For Prof King to continue to suggest that "we did attempt to validate Fred Brown's test" is absurd. There was indeed "confusion in Britain between the Cepheid mystery test and the real time PCR test". In the Veterinary Record on 6 October 2001, "Evaluation of a portable, 'real-time' PCR machine for FMD diagnosis", Alex Donaldson and his team reported poor results, stating that:"The reagents used in the assay were recommended by the manufacturer of the instrument" - but of course they were not recommended by the manufacturer, only by Cepheid - who, of course, didn't know and were guessing. Had the real time PCR test been properly trialled with the correct reagents - in other words, if the US offer had been courteously accepted - the story of FMD in 2001 would be very different. But Professor King told the EFRA Committee that "there are very serious questions to be asked about the use of that machine in the field, in particular the problem of cross-contamination". If one studies the letter and compares it with what Professor King and Dr Donaldson were saying in March 2001 at that EFRA Committee meeting one is struck by a feeling of great regret at what may well have been a genuine but tragic mistake.This transcript was sent to Alan Beat's smallholders.org newsletter - and we reproduce it here with gratitudeOn the 9th of March 2001, an offer of help came from the USDA collaborating with Tetracore to provide a sensitive real time PCR farmgate test
and, if required, an experienced team to carry out the work. It had been successfully laboratory tested by the USDA and required validation in the field. Its convenient size, speed and simplicity of use was even demonstrated here on BBC television by Tetracore. But Pirbright turned down the offer on the grounds of lack of time.
Seven months later Pirbright took the very same machine and started their own laboratory trials Failing in the first instance to get good results, they went to press (The Veterinary Record 6 Oct 2001)* where they falsely claimed that Cepheid, the manufacturer of the PCR machine, had recommended and provided the wrong materials. Later in the same letter they triumphantly claim success by changing to those they would normally use - Cepheid do not provide or give advice on test materials.
lack of cooperation may have been due to an economic conflict of interest
Evidence submitted to the Royal Society Inquiry of Edinburgh by the Director Patent and Licensing Affairs United Biomedical Inc. "... Clearly, safety and MAFF regulations were not the controlling factors here, but rather a desire to exploit their privileged position as the World Reference Centre to restrict competition. IAH-Pirbright is now involved with a competitor of UBI for the commercialization of their own NS test so it appears that their lack of cooperation may have been due to an economic conflict of interest. To put a kinder light on it, perhaps they simply decided to retain an intellectual exclusivity to FMD immunoassays. Either motivation is equally unethical and retarded development of FMD immunoassays...."
Rapid on-site PCR "....the real-time PCR assay for foot and mouth disease virus detects all seven FMD virus serotypes and differentiates this virus from other RNA viruses of animals and man and specifically from three viruses that cause almost identical diseases in livestock, namely swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses. The assay detects as few as 10 virus particles, well below the number required to establish an infection and is more sensitive than cell culture. Significantly, this has been found to be a preclinical test: in experimentally infected cattle, sheep and pigs, foot and mouth virus can be detected 24 to 48 hours before the onset of clinical signs of disease." (read in full) http://www.nuengr.unl.edu/cet/Research/LabNotes/nworthy1.html
Professors Develop Advanced DNA Replication Technology
by Roxane GayImagine being able to diagnose a viral strain at the site of an outbreak or identifying a deadly pathogen on the battlefield. Professors Hendrik Viljoen (chemical engineering) and George Gogos (mechanical engineering), both from the University of NebraskaLincoln, have been awarded a $1.44 million grant over five years from the National Institutes of Health (NIH) to further their development of faster Polymerase Chain Reaction (PCR) technology. PCR is a technique for amplifying DNA for diagnostic purposes wherein a sample of target DNA is replicated many times over to enable gene sequencing and identification. The key to our technology is that were able to amplify DNA in five to ten minutes, Viljoen said. Our device is also rugged, transportable and reliable. The rapid PCR uniquely positions us to pursue two other technologies. We can measure the PCR kinetics and the results are included in intelligent software, which will be part of the next generation of PCR thermocyclers. We have also started a program in assembly PCR. Short pieces of DNA are assembled, under conditions to minimize mutations, into larger structures.
To enable this rapid amplification, Viljoen and Gogos have integrated a novel device to produce the heating and cooling gases necessary for the thermocycling of the DNA. This device makes our technology amenable to field usage, Viljoen said. And it can handle volumes from 5 microliters to 40 microliters with outstanding sensitivity, while producing a high yield. The grant will be used to add optical detection, establish protocols for reverse transcription and the quantification of PCR, as well as to collect kinetic data of various polymerase enzymes to create mathematical models. The researchers have partnered with Michael Nelson, president of local biotechnology firm Megabase Research Products. The firm provides the required biochemistry expertise. This is an interdisciplinary project. Putting together a group of chemical engineers, mechanical engineers and biochemists has been very critical to the success of the project, Gogos said. We have built a device with vast medical and non-medical applications which at the same time is a scientific instrument for basic studies.
The implications for this innovative technology are many. We hope to form cross-disciplinary teams of researchers to look at parallel applications of this technology, said Dipanjan Nag, a technology development associate with the UNL Office of Technology Development, which provided the researchers with an additional $75,000 grant for further development of the technology. This NIH grant demonstrates that we are at the cutting edge of research, Nag said. And it has tremendous potential in biosecurity and bioterrorism related research.
See also: http://www.dailynebraskan.com/vnews/display.v/ART/2004/07/19/40fc058f93db5
http://www.medinews.com/GMEDTS32olcgi/ts.cgi?tsurl=0.59.13813.0.0
30-Minute PCR Technology
By medinews.com staff writers
Posted on 21 December 2004
A portable polymerase chain reaction (PCR) system automates all the steps, including sample preparation, allowing operation by nonscientist users in the field and providing results in only 30 minutes.
All the instruments used in the process are protected by a portfolio of 30 patents and incorporate a direct heating system that uses a plastic to rapidly heat and cool the samples. When combined with the detection and sample preparation chemistries, direct heating allows several test assays to be run in a single rapid reaction.
The process was originally developed for fast, accurate battlefield detection of biologic warfare agents such as anthrax, but has wider potential applications in human care. Two systems close to market launch are the NPT (near-patient testing) Gold for detection of chlamydia in hospitals and clinics and the PCR-Light, for field applications such as detection of foot-and-mouth disease and outbreaks of food poisoning. The systems are being marketed by Enigma Diagnostics (Porton Down, UK).
My task is now to devise and implement a licensing and commercial strategy that will enable us to successfully exploit the many potential applications areas both in the UK and internationally, noted John Thornback, new CEO of Enigma Diagnostics.pdf file of Real-Time Reverse Transcription PCR Detection of Foot-and-Mouth-Disease Virus Using the R.A.P.I.D.® System by Katy M. Andrews, Michael D. Powers, Gordon B. Ward, Thomas McKenna, Deepika de Silva Idaho Technology Inc., Salt Lake City, UT, 2APHIS USDA, Plum Island Animal Disease Ctr., Plum Island, NY.
"This study evaluates the ability of two real-time Reverse Transcription Polymerase Chain Reaction (RT-PCR) assays to independently detect the presence of Foot-and-Mouth-Disease Virus (FMDV) RNA. Assays to amplify the internal ribosomal entry site (IRES) and RNA polymerase regions of the FMDV genome recognize all seven existing serotypes. Both assays can effectively evaluate the presence of FMDV in various bovine samples, including blood, serum, saliva, nasal swabs, and epithelial tissue..... Real-time RT-PCR using the Ruggedized Advanced Pathogen Identification Device (R.A.P.I.D.) System is an ideal platform for fast, sensitive, and specific identification of FMDV...."
From the submission to the Royal Inquiry by the FMDF
RAPID ON-SITE DETECTION OF FOOT AND MOUTH DISEASE VIRUS
Those puzzled and frustrated by the seeming lack of technological breakthroughs in control of foot and mouth and other foreign animal diseases should not be discouraged by recent lacklustre results reported for foot and mouth virus detection by real-time polymerase chain reaction (PCR) on a portable device (Donaldson et al Vet Rec 149 6 Oct 2001).This technology is now so well developed for high-consequence pathogen detection in defence, public health, law enforcement and agriculture in the United States (U.S.) that it is clear that those indifferent results can be explained entirely by the inappropriate choice of reagents and assay conditions.
Furthermore, the caveats raised about potential limitations on applicability of the technology have not been found valid in experienced hands.
To understand the current frontiers of high-consequence pathogen detection elsewhere in the world, British government officials, livestock owners, practitioners and other interested parties should know the pedigree of this technology.
It was essentially driven by the needs of the U. S. Defense Department, to detect biological threat agents quickly, in the field and with such a high level of confidence that there would be time to take protective measures (Higgins et al., 1999).
To solve these problems, the Defense Department initiated revolutionary approaches to pathogen detection.
One of these is the portable real-time PCR machine, which is now widely deployed.
The term "real-time" refers to the ability to monitor all stages of the reaction and identification as it proceeds, rather than to have to wait until the end for a result.
"Portable" means that the device is taken to the site of the problem and operated there by the military - it is not confined to a central laboratory staffed by trained microbiologists.
Recently, as U. S. public health and law enforcement officials have come to realize that these same biological threat agents might be employed against civilian populations, they too have had to confront the problem of detecting high-consequence pathogens, outside the comfort of a reference laboratory and have again adopted portable real-time PCR devices as a way to provide fast, accurate answers wherever the pathogen might be present.
Veterinary medicine is also deeply involved in high-consequence pathogen detection - for control of infectious diseases moving swiftly through international boundaries and perhaps also, deliberately introduced diseases for the purpose of overwhelming conventional defences.
Hence, the Agricultural Research Service (ARS) of the U.S. Department of Agriculture (USDA) has begun to develop a uniform system of animal, plant and zoonotic pathogen detection, identification and epidemic response.
There are two components:
1. Rapid on-site tests that detect and identify important animal and plant pathogens.
The rapid detection and identification tests are performed with standardized reagents designed to work on a common device platform for all assays. Several devices are already commercially available and others are close to production. The most popular devices are made by Idaho Technology Inc. (www.idahotech.com) and Cepheid Inc. (www.cepheid.com).
2. An Internet-based information technology programme that incorporates these assays into an integrated management scheme to focus assets for rapid outbreak control in real time. This system is fully compatible with that used by U. S. military, public health and law enforcement agencies, which obviously maximises its utility. This is not a new test system that is an incremental improvement over the past - it is a fundamentally new way to control highly-infectious disease epidemics.These devices both work in the same way.
Future models from these and other manufacturers are expected to become smaller, quicker and cheaper to purchase and operate - hand held machines are already available. The devices cost between £15,000 and £30,000.
Real-time PCR assays are performed on a small, portable computer controlled device operating on mains or car battery power. The device is specifically designed to be taken to or near the site of the problem and used there by a person with limited training.
An integral global positioning system can identify the exact location of the device. A wireless Internet connection provides world-wide communication, so that distant experts can "look over the shoulder" of the person conducting the assay, to offer advice, expert analysis and validation of assay performance as it proceeds.
Instead of taking the sample to the expert, at a distant site for analysis, the sample is analysed on the spot and the data sent electronically to the expert and back to the operator with whatever advice is needed.
This immediately saves one or two or more days. If time is gained, multiple alternate courses of action become possible for those charged with taking action to control the disease outbreak. This is the true significance of the technology (Breeze, 2001).
Sample preparation is minimal and can be automated. The process of preparation inactivates infectious agents, including foot and mouth disease virus
. All necessary reagents are contained in a single-assay sealed tube in a freeze-dried form stable under a wide range of environmental conditions for over a year. Reagents are produced to ISO 9000 standards and weekly updates of quality control and quality assurance data for each batch are available over the Internet. Sample collection, preparation and the assay itself can be completed in 90 minutes after arriving on site, but positive results can be obtained much earlier.
Real-time PCR assays for foot and mouth disease and classical swine fever virus detection and identification were described and demonstrated by scientists from the USDA at the 105th Annual Meeting of the U.S. Animal Health Association/44th Annual meeting of the American Association of Veterinary Laboratory Diagnosticians held in November 2001 in Hershey, Pennsylvania.
Members of the FMD Forum were in the audience and had the opportunity to see the research results and watch assays being conducted.
Briefly, data were presented to show that the real-time PCR assay for foot and mouth disease virus detects all seven FMD virus serotypes and differentiates this virus from other RNA viruses of animals and man and specifically from three viruses that cause almost identical diseases in livestock, namely swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses.
The assay detects as few as 10 virus particles, well below the number required to establish an infection and is more sensitive than cell culture.
Significantly, this has been found to be a preclinical test: in experimentally infected cattle, sheep and pigs, foot and mouth virus can be detected 24 to 48 hours before the onset of clinical signs of disease.
A single assay costs about £5.
The classical swine fever real time PCR assay detects all the strains of this virus and differentiates these from similar viruses, such as border disease and bovine viral diarrhoea viruses. This test is also more sensitive than cell culture and has again been found to be preclinical - detecting infected animals several days before the onset of clinical signs.
Once a positive identification is made on-site, the information technology part of the system allows those responsible to take immediate action in cooperation with other parties who must become involved.
Since the device location is known by global positioning, officials can immediately see electronically a map of the area around the infection, predict where infection may have been spread by recent wind, map this spread according to geography and topography, identify quarantine zones, set up control measures (such as road blocks) and identify farms at risk where animals should be tested immediately to detect any infection.
The system is designed to coordinate Government officials, academia and private industry, cooperatively, to focus all available resources on immediately stamping out such an introduction through quick, targeted and science-based interventions.
Consequentially, in future, the British people - once aware that such amazing and proven science is available from our friends across the water - will not tolerate the little Englander attitude and medieval approach, adopted for the control of this outbreak
References 1. Breeze, R.G. Foot and mouth disease preparedness -USA. Promed-mail, 20010520.0981, May 20, 2001. 2. Donaldson, A. L., Hearps, A., and Alexandersen, S. Evaluation of a portable, "real-time" PCR machine for FMD diagnosis, Veterinary Record,149, 430, 2001. 3. Higgins, J.A., Ibrahim, M.S., Knauert, F.K., Ludwig, G.V., Kijek, T.M., Ezzell, J.W., Courtney, B.C., and Henchal, E.A.. Sensitive and rapid identification of biological threat agents. In "Food and Agricultural Security: Guarding against natural threats and terrorist attacks affecting health, national food supplies and agricultural economics". Editors Frazier, T.W. and Richardson, D.C. Annals of the New York Academy of Sciences, 894, 130-148, 1999.
About rapid diagnosis tests
"As we sit here now there are no validated tests and of course were all working hard towards that objective." Professor David King, Chief Scientific Advisor to the UK Government, on the Today programme, December 18 2002
March 2 2004 ~ RT-PCR diagnosis against FMD to be tested in Texas.
AgNews "Experimental technology to rapidly detect foot-and-mouth disease will be tested in Texas this spring as the result of an agreement between the U.S. Department of Agriculture and the Texas A&M University College of Veterinary Medicine. The agreement, which also will test classical swine fever, means the Texas A&M researchers will be responsible for testing cattle and hogs with new assays to determine the tests' accuracy in populations of disease-free animals. ....
Currently, foot-and-mouth testing may only be performed at the U.S. Plum Island Animal Disease Center in New York, a high-security biocontainment facility. The usual method of confirming foot-and-mouth includes virus isolation a procedure that, while accurate, may take up to a week to obtain results plus the time required to ship samples to Plum Island. New, rapid tests that could be performed in the field would enable officials to quickly detect and stop massive spread in a disease outbreak, researchers said. ....
The new experimental testing procedures that will be evaluated use "real time" polymerase chain-reaction technology to identify genetic material specific for the viruses that cause foot-and-mouth and classical swine fever. No active foot-and-mouth virus will be used in Texas. "Such procedures can give results in less than one hour and could be modified to test livestock on location during outbreak situations," ...."
(The conference Pan American Health Organization (PAHO), gather in Houston, Texas to "give a final push towards the eradication of foot-and-mouth" tomorrow.)
Feb 25 2004 ~ 80% of all state public health laboratories in the US now have and use SmartCyclers.
It is, as Fred Brown said, "a beautiful piece of kit, simple and not costly" - and making use of it three years ago, as it was used in Uruguay in the same year, would have avoided bloodshed and trauma. The RT-PCR rapid diagnosis kit now used by the Pennsylvania Veterinary Laboratory - ( "in a matter of hours, it can determine both the presence and strain of the disease") is the Smart Cycler . We have confirmation from the journalist who wrote last Sunday's article in the Philadelphia Inquirer that the "new machine" is indeed the same machine that was offered to the UK government by the Agricultural Research Service (ARS) of USDA in early March 2001 for field tests. It is, as we hear from the Cepheid installer, now in 80% of all US state public health laboratories.
As was noted in tactfully phrased evidence to the Royal Society Inquiry (pdf. new window)"Unfortunately, yet understandably, Pirbright staff were too busy coping with the demands of epidemic control to explore new technology during the spring and summer of 2001 . As a result, my offer to provide the latest diagnostic technology was not taken up.
The Philidephia article noted that even with the help of the older, slower Bio-rad machine: ".. the state was able to announce that it had confirmed avian influenza, that the particular strain was virulent in poultry, and that it was unrelated to the type implicated in Thailand and Vietnam. The public was reassured that there was no Asian connection. Agriculture officials knew how big a quarantine was needed, and scientists had crucial details needed to start tracing the source of the infection."
Fortunately, we were able to take the devices and test system into the field in Uruguay in November 2001, where they performed splendidly on farm in a remote area..."
The Smart Cycler, with appropriate reagent, is considerably faster.Even now, three years on, we can find no mention of RT-PCR technology in the141 pages of the latest DEFRA Foot and Mouth Contingency Plan (pdf - slow - new window)
Feb 24 ~" a further indictment of the UK's refusal to recognise and grasp the same opportunity three years ago"
Comment from Alan Beat about the item on the Chinese tests posted on February 14, and which applies equally to the news of the RT-PCR test at the Pennsylvania Veterinary Laboratory :
"This technology is the very same that was offered to the UK authorities in the early stages of the 2001 FMD epidemic by their USA counterparts, and was bluntly refused on the grounds that it was "not validated" by the OIE (just before the contiguous cull, itself unvalidated, was introduced). By appropriate choice of reagent chemicals used, such tests can accurately identify and strain any viral infection, so the Chinese announcement is not in any sense a scientific advance, rather it is the practical application of well-established technology - and a further indictment of the UK's refusal to recognise and grasp the same opportunity three years ago."
"... the real-time PCR assay for foot and mouth disease virus detects all seven FMD virus serotypes
and differentiates this virus from other RNA viruses of animals and man and specifically from three viruses that cause almost identical diseases in livestock, namely swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses. The assay detects as few as 10 virus particles, well below the number required to establish an infection and is more sensitive than cell culture. Significantly, this has been found to be a preclinical test: in experimentally infected cattle, sheep and pigs, foot and mouth virus can be detected 24 to 48 hours before the onset of clinical signs of disease. A single assay costs about £5. ..." See full articleFeb 22 2004 ~ New DNA-based test speeds diagnosis of avian influenza
Philadelphia Inquirer Sunday 22Feb
" ...a new DNA-based test, capable of confirming the disease within hours, has arrived in labs around the region at a fortuitous time. ....About a year ago, the state bought DNA-testing equipment that can identify a virus within 24 hours of collecting the sample. A newer model, with a turnaround of several hours, arrived less than two weeks ago at the Pennsylvania Veterinary Laboratory in Harrisburg.
See also MasterAmp Real-Time RT-PCR Kit (pdf file), an example of the sort of kit now available. We assume that DEFRA has been looking into this new technology fo many months now. We mentioned the Chinese PCR kit on February 14th2004
The staff have yet to be fully trained and validated on the new equipment, but they lost no time running samples from the Lancaster farm on the new machine, known as real-time RT-PCR (reverse transcriptase-polymerase chain reaction). Their findings, confirmed by the National Veterinary Services Laboratories in Ames, Iowa, identified an H2 strain of avian flu - a concern, but not nearly as bad as the type found in Delaware.
A quarantine of the farm and screening of 16 flocks within five miles appear to have contained the infection, said state veterinarian John Enck...."
Jan 9 2003 ~ Rapid Diagnosis PCR tests: a peer-reviewed publication, lab validation, and successful field tests in South America.
Roger Breeze's ProMed posting of May 2001. ...getting on for TWO years ago. Much has moved on since then, including a peer-reviewed publication, lab validation, and successful field tests in South America.
Extract: "These devices offer rapid real-time detection and identification by polymerase chain reaction (PCR) assays, are designed for use on farm at the site of the problem as hand-held or portable units, and communicate real-time data via the Internet to those who need to know in order that immediate action can be taken. ..... The system is specifically intended to support immediate detection on-site by operators with limited training, not just by highly-trained personnel geographically restricted to centralized laboratories. ........ The FMD assay requires minimal sample preparation and results are available in less than 2 hours after collection. The assay detects all 7 FMD virus serotypes and differentiates the virus from near relatives and from swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses. In experimentally-infected animals, FMD virus can be detected well before the onset of clinical signs of disease. ...... instead of taking the sample to the expert in a central laboratory, the system takes the analytical data from the farm to the expert, so that any comment can be immediately returned to the person performing the analysis on the site. The system thus offers a time saving of at least 24 to 48 hours in definitive detection of virus. If time is gained, multiple alternate courses of action become possible for those charged with controlling the disease outbreak. This is the true significance of the system."
"we did attempt to validate Fred Brown's test and it didn't pass the validation"
said Professor David King on the Today Programme (Dec 18 2002) (See transcript below)
But here is an extract of the letter sent as evidence to the Royal Society Enquiry
It was also sent to the Lessons Learned Inquiry and given by hand to Lord Whitty
...Our real time PCR assay for foot and mouth disease (W) has been validated in the laboratory: it has proven to be a pre-clinical test for infection in cattle, swine and sheep, it detects all 7 serotypes of FMD virus and differentiates this infection from other viral diseases that cause similar clinical signs. The test is more sensitive than viral culture and will detect as few as 10 virus particles....
The research paper with these results appeared in the Journal of the American Veterinary Medical Association.
Some eight months after we had disclosed the existence of our x;h/lD test to Dr. Donaldson, we read in the Veterinary Record that the Pirbright Laboratory had subsequently established a relationship with Cepheid and conducted some experiments with FpvfB reagents supplied by that company (data published by Alex Donaldson and others in the Veterinary Record, 2001).
I have no idea what those reagents were because the paper does not describe them. But I can be sure that these reagents were not those developed by USDA-ARS and Tetracore because Cepheid does not have this proprietary information.
I hope there has been no confusion in Britain between the Cepheid mystery test and the real time PCR test developed at Plum Island...."
For Prof King to continue to suggest that "we did attempt to validate Fred Brown's test" is absurd. There was indeed "confusion in Britain between the Cepheid mystery test and the real time PCR test". In the Veterinary Record on 6 October 2001, "Evaluation of a portable, 'real-time' PCR machine for FMD diagnosis", Alex Donaldson and his team reported poor results, stating that:"The reagents used in the assay were recommended by the manufacturer of the instrument" - but of course they were not recommended by the manufacturer, only by Cepheid - who, of course, didn't know and were guessing. Had the real time PCR test been properly trialled with the correct reagents - in other words, if the US offer had been courteously accepted - the story of FMD in 2001 would be very different. But Professor King told the EFRA Committee that "there are very serious questions to be asked about the use of that machine in the field, in particular the problem of cross-contamination". If one studies the letter and compares it with what Professor King and Dr Donaldson were saying in March 2001 at that EFRA Committee meeting one is struck by a feeling of great regret at what may well have been a genuine but tragic mistake.This transcript was sent to Alan Beat's smallholders.org newsletter - and we reproduce it here with gratitudeOn the 9th of March 2001, an offer of help came from the USDA collaborating with Tetracore to provide a sensitive real time PCR farmgate test
and, if required, an experienced team to carry out the work. It had been successfully laboratory tested by the USDA and required validation in the field. Its convenient size, speed and simplicity of use was even demonstrated here on BBC television by Tetracore. But Pirbright turned down the offer on the grounds of lack of time.
Seven months later Pirbright took the very same machine and started their own laboratory trials Failing in the first instance to get good results, they went to press (The Veterinary Record 6 Oct 2001)* where they falsely claimed that Cepheid, the manufacturer of the PCR machine, had recommended and provided the wrong materials. Later in the same letter they triumphantly claim success by changing to those they would normally use - Cepheid do not provide or give advice on test materials.
lack of cooperation may have been due to an economic conflict of interest
Evidence submitted to the Royal Society Inquiry of Edinburgh by the Director Patent and Licensing Affairs United Biomedical Inc. "... Clearly, safety and MAFF regulations were not the controlling factors here, but rather a desire to exploit their privileged position as the World Reference Centre to restrict competition. IAH-Pirbright is now involved with a competitor of UBI for the commercialization of their own NS test so it appears that their lack of cooperation may have been due to an economic conflict of interest. To put a kinder light on it, perhaps they simply decided to retain an intellectual exclusivity to FMD immunoassays. Either motivation is equally unethical and retarded development of FMD immunoassays...."
Jan 10 ~"Clearly, safety and MAFF regulations were not the controlling factors here, but rather a desire to exploit their privileged position as the World Reference Centre to restrict competition."
From the letter submitted as evidence to the Royal Society (Edinburgh) Inquiry by the Director Patent and Licensing Affairs United Biomedical Inc. about the reluctance of Pirbright to let them have access to sera "..... IAH-Pirbright is now involved with a competitor of UBI for the commercialization of their own NS test so it appears that their lack of cooperation may have been due to an economic conflict of interest. To put a kinder light on it, perhaps they simply decided to retain an intellectual exclusivity to FMD immunoassays.
Either motivation is equally unethical and retarded development of FMD immunoassays. Without access to the Pirbright World Reference Centre collection, we were unable to fully standardize the UBI tests at that time..We believe it is perfectly OK for them to profit from their own tests, but as the publicly funded OIE-designated World Reference Center, it is improper for them to reserve their resources to themselves or to use an arbitrary standard to exclude companies from the ranks of qualified FMD researchers. (Unfortunately, an anti-company attitude is more pervasive among FMD researchers than it is in most fields of the life sciences and in this age of biotechnology, this attitude needs to be seriously questioned.) ..Dr. Brown and others at the USDA also have been working on a device to detect FMDV RNA by PCR, in real-time, in collaboration with Tetracore, Inc., another U.S. biotechnology company. This project is also worth your looking into, independently of IAH-Pirbright. .UBI has not been involved with that project. UBI also has an FMD vaccine program. IAH-Pirbright has provided advice and has offered access to their facilities. The conflict of interest seems to be limited to diagnostics." MoreJan 10 ~ "it is a breach of duty that this has been allowed to pass"
Extract from Dr Watkins' Submission to the Royal Society of Edinburgh FMD Enquiry ".... During the early stages of the FMD epidemic Dr Noel Mowat offered to help educate MAFF officials and vets on FMD virology. Dr Mowat used to work at Pirbright and ran courses on FMD infection at Pirbright. His offer was refused.
On the 9th of March 2001, an offer of help came from the USDA collaborating with Tetracore to provide a sensitive real time PCR farmgate test and if required an experienced team to carry out the work. It had been successfully laboratory tested by the USDA and required validation in the field. Its convenient size, speed and simplicity of use was even demonstrated here on BBC television by Tetracore. But Pirbright turned down the offer on the grounds of lack of time.
Seven months later Pirbright took the very same machine and started their own laboratory trials Failing in the first instance to get good results, they went to press (The Veterinary Record 6 Oct 2001)* where they falsely claimed that Cepheid, the manufacturer of the PCR machine, had recommended and provided the wrong materials. Later in the same letter they triumphantly claim success by changing to those they would 'normally' use - Cepheid do not provide or give advice on test materials. ......They (Pirbright) have also insisted that they could not use an anti-NSP test, as it also was not validated. Antibody to non-structural virus proteins (NSP) enables vaccinated herds or flocks to be distinguished from infected ones. Again they use their own in-house test rather than validate any commercial anti-NSP tests, also offered them during this epidemic from UBI for example. What is going on at Pirbright? Pirbright has confined itself to in-house tests, producing the materials and developing its own protocols. It has refused to undertake validation of commercial FMD tests such as those produced by Michael Walker at Genesis. There is no other laboratory in Britain that is allowed or could undertake to validate FMD tests - it is a breach of duty that this has been allowed to pass..." (more)Jan 9 ~ Rapid Diagnosis PCR tests: a peer-reviewed publication, lab validation, and successful field tests in South America.
Roger Breeze's ProMed posting of May 2001. Much has moved on since then, including a peer-reviewed publication, lab validation, and successful field tests in South America.
Extract: "These devices offer rapid real-time detection and identification by polymerase chain reaction (PCR) assays, are designed for use on farm at the site of the problem as hand-held or portable units, and communicate real-time data via the Internet to those who need to know in order that immediate action can be taken. ..... The system is specifically intended to support immediate detection on-site by operators with limited training, not just by highly-trained personnel geographically restricted to centralized laboratories. ........ The FMD assay requires minimal sample preparation and results are available in less than 2 hours after collection. The assay detects all 7 FMD virus serotypes and differentiates the virus from near relatives and from swine vesicular disease, vesicular exanthema and vesicular stomatitis viruses. In experimentally-infected animals, FMD virus can be detected well before the onset of clinical signs of disease. ...... instead of taking the sample to the expert in a central laboratory, the system takes the analytical data from the farm to the expert, so that any comment can be immediately returned to the person performing the analysis on the site. The system thus offers a time saving of at least 24 to 48 hours in definitive detection of virus. If time is gained, multiple alternate courses of action become possible for those charged with controlling the disease outbreak. This is the true significance of the system."Jan 9 ~ FMD Contingency Plan: no reference to new technologies - rapid field diagnosis and linked GIS systems. On the contrary:
DEFRA's Contingency Plan (external link) "8.2 Transport of samples
8.2.1 DVMs will ensure they have access to local couriers to transport blood samples during an animal disease outbreak as per SVS standard instructions."
So is there really no plan to use the already available and excellent real time PCR tests? Defra is continuing to maintain its option of slaughter on contiguous premises and of "firebreak" culls:
"7. If FMD is Confirmed (through Clinical Examination or Laboratory Test) ..... Further action will depend on the circumstances of a particular outbreak and depending on the scientific and veterinary advice. Additional options and strategies which are potentially available include:But an "open consultation" is certainly a welcome development - if it means what it says. It is hoped that interested parties will contact DEFRA about this. Email: contingency.comments@defra.gsi.gov.uk
- emergency vaccination (either to live or to kill, within an area or in a ring around an area);
- culling of other livestock exposed to the disease (e.g. premises under virus plumes, contiguous premises); and
- (subject to the Government's Animal Health Bill becoming law) pre-emptive or 'firebreak' culling of animals not on infected premises not dangerous contacts or not necessarily exposed to the disease, in order to prevent the wider spread of the disease outwith an area."
No stress on the importance of targeted vaccination, which requires better diagnostics/detection technology and better data management than indicated in this paper.Jan 1-6 ~ "we did attempt to validate Fred Brown's test and it didn't pass the validation"
said Professor David King on the Today Programme (Dec 18)
We will remind readers again of what actually happened since Professor King doesn't seem to remember. Here is an extract of the letter sent as evidence to the Royal Society Enquiry
It was also sent to the Lessons Learned Inquiry and given by hand to Lord Whitty
...Our real time PCR assay for foot and mouth disease (W) has been validated in the laboratory: it has proven to be a pre-clinical test for infection in cattle, swine and sheep, it detects all 7 serotypes of FMD virus and differentiates this infection from other viral diseases that cause similar clinical signs. The test is more sensitive than viral culture and will detect as few as 10 virus particles....
The research paper with these results appeared in the Journal of the American Veterinary Medical Association.
Some eight months after we had disclosed the existence of our x;h/lD test to Dr. Donaldson, we read in the Veterinary Record that the Pirbright Laboratory had subsequently established a relationship with Cepheid and conducted some experiments with FpvfB reagents supplied by that company (data published by Alex Donaldson and others in the Veterinary Record, 2001).
I have no idea what those reagents were because the paper does not describe them. But I can be sure that these reagents were not those developed by USDA-ARS and Tetracore because Cepheid does not have this proprietary information.
I hope there has been no confusion in Britain between the Cepheid mystery test and the real time PCR test developed at Plum Island...."
For Prof King to continue to suggest that "we did attempt to validate Fred Brown's test" is absurd. There was indeed "confusion in Britain between the Cepheid mystery test and the real time PCR test". In the Veterinary Record on 6 October 2001, "Evaluation of a portable, 'real-time' PCR machine for FMD diagnosis", Alex Donaldson and his team reported poor results, stating that:"The reagents used in the assay were recommended by the manufacturer of the instrument" - but of course they were not recommended by the manufacturer, only by Cepheid - who, of course, didn't know and were guessing. Had the real time PCR test been properly trialled with the correct reagents - in other words, if the US offer had been courteously accepted - the story of FMD in 2001 would be very different. But Professor King told the EFRA Committee that "there are very serious questions to be asked about the use of that machine in the field, in particular the problem of cross-contamination". If one studies the letter and compares it with what Professor King and Dr Donaldson were saying in March 2001 at that EFRA Committee meeting one is struck by a feeling of great regret at what may well have been a genuine but tragic mistake.Real-time PCR
Real-time PCR differs from standard PCR in that the amplified PCR products are detected directly during the amplification cycle using hybridisation probes, which enhance assay specificity. Various real-time methods, such as TaqMan, Scorpions, FRET, or Molecular Beacons assays, have become popular tools for detection of infectious agents. Real-time PCR has been used for the detection of bacteria, viruses or parasites from a range of animal species (2, 6, 8). These new assays have several advantages over the 'classical' conventional or nested PCR methods. Only one primer pair is used, providing sensitivity often close or equal to traditional nested PCR but with a much lower risk of contamination. Fluorescence, indicating the presence of the amplified product, is measured through the lid or side of the reaction vessel thus there is no need for post-PCR handling of the amplified DNA. These procedures are considerably less time-consuming compared with traditional post-amplification PCR product detection in agarose gels followed by ethidium bromide staining and again, the risk of contamination is reduced. The use of a 96-well microtitre plate format, without the need for nested PCR, allows the procedure to be automated and suitable for large-scale testing (5). Diagnosis can be further automated by using robots for DNA/RNA extractions and pipetting. Compared with classical amplification methods, a further advantage of the real-time PCR is that it is possible to perform quantitative assays (6).
Multiplex PCR
PCR reactions using multiple primers directed at different targets in a single assay are referred to as multiplex PCR assays. In multiplex PCR, various infectious agents can be detected and differentiated in a single reaction vessel at the same time. The different PCR targets amplified in a standard PCR assay are identified based on PCR product size. The use of 'classical' nested PCR methods for the construction of a multiplex assay is complicated by the need for targets of different sizes, as well as primers that may 'compete' with each other in the same reaction mix, both of which can negatively impact PCR efficiency. In contrast, the concept of real-time PCR (single primer pairs) provides excellent possibilities for the construction of highly sensitive multiplex systems (2, 4) based on more uniform target size, uniform amplification conditions, and differential detection of targets using specific hybridisation probes labelled with different fluorophores.