Foot-and-mouth virus not as infectious as thought: new research

[Shiloh]

Source: http://www.canada.com/technology/Foo...988/story.html

Foot-and-mouth virus not as infectious as thought: new research
By Margaret Munro, Postmedia News May 5, 2011 3:02 PM

A dreaded animal disease that can, and has, brought countries to their knees is not always the microbial villain it is portrayed to be, according to new research.

The foot-and-mouth virus that triggered a national disaster in the United Kingdom in 2001, turns out to be about half as infectious as thought, says a study to be published Friday.

It also suggests culling of livestock ? like the recent slaughter of more than a million pigs and cattle in Korea to try stop a foot-and-mouth outbreak ? may be overused.

Experts stress infected animals need to be killed, but they say slaughtering livestock that "may" have been exposed to the virus can be overkill...

[Tonka]

Re: Foot-and-mouth virus not as infectious as thought: new research

http://www.elpais.com.uy/110506/pnacio-564578/sociedad/animales-solo-transmiten-aftosa-durante-40-horas-segun-estudio/

Spanish to English translation

Animal disease transmitted only 40 hours, according to report
Finding. If the global test, mass slaughter would be reduced

The FMD-infected animals transmit the disease only after the first symptoms. That concludes a scientific study, which calls into question the international bases of disease control.

Research published today in the journal Science suggests that cattle affected by FMD is infectious only after signs and for a short period of time. The findings suggest that the application of sanitary rifle, used to stop the spread of the disease by culling, could be reduced.

FMD is a viral disease that affects cattle as well as pigs, sheep and other ruminants. Of the 177 countries of the World Organization for Animal Health (OIE), 100 still have problems caused by the disease in terms of lost production and restriction of commercial markets (many countries do not allow meat from areas with disease).


One of the most widespread measures to control the spread of the virus is the sacrifice of both animals infected as those found within the site of infection and may have acquired the disease.

After ten years free of disease, the virus was readmitted to Uruguay in 2000, with a focus on Artigas was brought under control. Only 3,000 animals were slaughtered there. A year later, there were new outbreaks and disease spread across the country. This year the situation caused losses of U.S. $ 700 million.

Since then the whole Uruguay vaccine rodeo. In 2003 the country regained FMD-free status (with vaccination). The research could bring, globally, changes from new outbreaks.

STUDY. Carried out jointly between the University of Edinburgh and the Pirbright Laboratory in the UK, the study focused on identifying the precise periods of incubation and infection. They found that although the virus can be detected in a blood sample from a cow that does not mean that the animal actually has the ability to infect another.

In fact, according to the results, a cow disease is only infectious for 1.7 days, ie for less than 48 hours. After that time, immune responses start to work and limit viral replication.

Charleston led by Bryan and Mark Woolhouse, the researchers infected cows with FMDV (foot and mouth disease virus) and studied how the virus was transmitted to uninfected animals. In 28 attempts to infect healthy cows, located near the sick for eight hours, the researchers looked only eight successful transfers.

In light of its findings, Charleston and colleagues suggest that cows with FMDV infectious only get about half a day after the appearance of clinical signs of disease. These include fever and sores in the form of blisters in the mouth, udder and between the hooves.

"We now know that there is a window that, if the affected livestock is detected and immediately removed from the herd may be no need for preventive culling in the immediate area of an infected farm," Woolhouse said.

Charleston, meanwhile, told El Pais that the finding demonstrates the importance of preclinical testing to identify the disease early. "Knowing that it is unlikely that the infection transmitted by animals before they begin their clinical symptoms, a period in which the virus is easily detectable in samples of body fluids, know that the development of accurate diagnostic techniques could be valuable to reduce transmission, "he said.

In this line Charleston and his team called veterinary communities to find practical tools that can diagnose the disease in the field, before clinical signs appear. According to the researchers, if the VFA could be detected in cattle only 24 hours before symptoms appear, the producers would have time to remove the infected animals before they transmit the virus.

"It is technically and logistically challenging, but our work shows that the potential benefits could be much higher than we did before," said researcher Pirbright Laboratory in the UK.

NEW. Francisco Muzio, director of Livestock Services of the Ministry of Livestock, Agriculture and Fisheries, said the research casts doubt on concepts that have been the basis of many investigations. "All available research says that before the appearance of the characteristic lesions of the disease, the animal is already shedding virus in saliva or urine," he said.

"It is what is called an incubation period ranging from who was infected until they have symptoms, which can be seven days. Within that time, it is first infected, then the virus gets into your blood and there begins to eliminate, "said Muzio, who is part of the Standing Veterinary Committee (SVC), regional watchdog.

If it is found globally in spite of having the virus has no animal infectivity, the basic concepts remain unchanged, estimated Muzio. And therefore also the actions.

The search for new strategies to prevent the slaughter of herds and is one of the lines promoted by international health authorities face food shortages worldwide.

In America, the surveillance is aimed at keeping the state free of FMD with vaccination, on the grounds that the producers suspected alerted against infection (in Uruguay there are 15 to 20 per year) and a Hemispheric Plan for Eradication of Foot 2012 - 2020.

They point to early detection
What characteristics did the research?

The study was conducted in Holstein Friesian cows (Holstein breed) and pointed to the type O virus, which is what caused the epidemic in the UK in 2001. Were conducted under experimental conditions and will be tested in the open field.

What are the next steps?

We are developing diagnostic methods that can detect the virus when found in small quantities. This study demonstrated the importance of early detection of disease transmission control.

* Research, Pirbright Laboratory, UK.

[Gert van der Hoek]

Re: Foot-and-mouth virus not as infectious as thought: new research

Mass cull obsolete in future FMD outbreaks

//09 May 2011

The mass culling of cattle to control outbreaks of foot and mouth disease may soon be a thing of the past, writes The Independent following a report of scientists who have made a breakthrough in understanding how the virus is transmitted.

A study has established a hidden "window of opportunity" between the point when a cow becomes infected with the foot and mouth virus and the time when she is able to transmit the virus to another animal.

Scientists said that this discovery, combined with the realisation that cattle are only infectious for about a two-day period, means it should be possible to identify infected animals and eliminate them from a herd before they can pass on the infection.

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