Philippines Moves to Fight Pig Ebola

[Animal 0]

DECEMBER 19, 2008 Philippines Moves to Fight Pig Ebola
By JONATHAN CHENG


Global health authorities are preparing an emergency mission to the Philippines after U.S. scientists discovered a strain of the Ebola virus in dead pigs there that had previously only been found in monkeys.



Unlike more-deadly strains of Ebola virus, health officials say this particular strain, known as the Reston strain, has never caused human illness or death, and it's not immediately clear there is a public-health issue.

But health officials say it is too early to rule out a possible threat to humans, and expressed concern over the fact that this incident, first revealed in an Oct. 30 teleconference between the Philippine government and U.S. health authorities, wasn't made public until a news conference for local media in Manila last week.



Farmers gather pigs for slaughter Thursday in Manila. Authorities in the Philippines sought to allay public fears about the spread of the Ebola virus.
Pigs have served as genetic mixing vessels for viruses that pass from animals to humans, which makes the Philippine discovery significant. "When a virus jumps species, in this case from monkeys to pigs, we become concerned, particularly as pigs are much closer to humans than monkeys in their ability to harbour viruses," says Peter Cordingley, Western Pacific spokesman for the World Health Organization in Manila.

Philippine authorities say they have quarantined affected farms, canceled plans for the country's first official exports of pork, and conducted tests on hog farmers and slaughterhouse workers.

Authorities say there have been no signs of humans infection in the outbreak. It's unclear whether any infected pigs were sold for consumption. Experts say it could take weeks to determine how the pigs were infected and the threat to humans.

According to officials at the WHO, the World Organization for Animal Health and the Philippines' Bureau of Animal Industry, pig farmers in three provinces near the capital of Manila began noticing high rates of sickness and death among their livestock as early as May.

In August, Philippine authorities sent samples from the dead pigs to the Plum Island Animal Disease Center in New York, where scientists detected the presence of several diseases, including a devastating pig virus known as porcine reproductive and respiratory syndrome, or blue-ear pig disease.

Weeks later, during the Oct. 30 teleconference, authorities at the Philippines' Department of Agriculture were notified that scientists had further discovered Ebola Reston virus in six of the 28 pig samples sent to the U.S.

The Philippine government waited until Dec. 10 to make the presence of Ebola Reston virus public, citing concern for the pork industry and a lack of evidence that humans were in any danger.

Davinio Catbagan, director for the Philippines' Bureau of Animal Industry, said the government first consulted with people in the swine industry and only later notified the Department of Health. Mr. Catbagan said authorities were aware of the public-health importance of the recent discovery, but that the available medical literature didn't suggest any threat to humans.

The WHO said it learned of the disease through the United Nations' Food and Agriculture Organization in late November.

Concerns have been deepening across Asia about diseases among stocks of chickens and pigs, including H5N1 avian influenza and blue-ear pig disease. The latest announcement forced the Philippines to abort its first-ever commercial export of pork, which was to be made to Singapore earlier this month.

According to people at the WHO and the Paris-based World Organization for Animal Health, known by its French acronym OIE, Philippine authorities decided to go public only after being pressured by those two groups and the FAO. Dr. Bernard Vallat, director-general of the OIE, said it was "not an easy negotiation" to persuade Philippine authorities to go public with the news.

He said the pigs were most likely killed by another disease, but that the presence of the Ebola Reston virus in pigs should be investigated to assess the risk to humans.

The Ebola virus comes in five distinct strains, three of which are associated with the high-fatality outbreaks that first appeared in the Congo in 1976. In 1989, scientists discovered what would be known as the Reston strain of the Ebola virus among monkeys imported from the Philippines and kept for research in a Reston, Va., lab. A handful of humans were infected in that case, but only one person showed any symptoms, and fully recovered.

According to the WHO, the Ebola Reston virus can be identified only by laboratory testing, and anyone eating pork even from healthy pigs should cook the meat thoroughly. Meat from a sick animal should never be eaten. According to the FAO, the Ebola Reston virus is transmitted by air, unlike African strains of the virus which are transmitted through direct contact with bodily fluids.

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