Aug 26, 2005 (CIDRAP News) – Reports today said three rare palm civets that recently died in captivity in Vietnam were infected with an H5N1 avian influenza virus, adding another species to the list of those susceptible to the pathogen.
The three Owston's palm civets died in June, and tests of samples in a Hong Kong laboratory detected the H5N1 virus, according to Reuters and Agence France-Presse (AFP) reports. The animals died in the same cage in Cuc Phuong National Park, about 55 miles south of Hanoi.
Staff members at the park said no other animals or people had fallen ill.
In addition to birds and humans, H5N1 viruses have been known to infect pigs, housecats, tigers, and leopards. The virus has killed millions of poultry and at least 57 people in outbreaks in Asia since late 2003.
Civets figured in another relatively new infectious disease: SARS (severe acute respiratory syndrome). Chinese scientists concluded that masked palm civets—a different species from Owston's—were the main animal source of the SARS virus, which infected about 8,000 people around the world in 2003. Civets are used for food in southern China.
The civets that died of avian flu were a female and two offspring, all of which had been born in captivity, reports said. It was not clear how they became infected.
Reuters quoted Do Van Lap, a manager at the park, as saying, "How they were infected remains unknown as they were raised together with 20 other civets, their cages close to each other, but the remaining civets are strong."
Lap said initial suspicion fell on park staff members who lived in a village where some chickens had died, but tests did not find the virus. He said the civets were not fed chicken.
The story said Cuc Phuong National Park has a wildlife protection project that involves raising peacocks, pheasants, freshwater turtles, and deer in captivity, as well as civets. "All the remaining animals are safe, so we reckon the three civets are isolated cases," Lap told Reuters.
In an Associated Press (AP) report, Scott Robertson, technical adviser for the civet conservation program at the park, commented, "It's another good example of how dangerous this thing [the H5N1 virus] is." He said the WHO and Vietnamese health officials were expected to test park employees.
Peter Horby, a WHO epidemiologist in Hanoi, said the finding does not signal an increased risk of avian flu in humans, since people have less contact with civets than with poultry, according to the AP. Poultry have been the source of nearly all human cases so far.
Owston's palm civet is an endangered species that is confined to parts of northern Vietnam, northern Laos, and neighboring areas of China, according to a report from Vietnam's National Center for Scientific Research.
Also in Vietnam, a pilot program to vaccinate poultry against avian flu in two provinces is running behind schedule, according to a report today from the Vietnam News Agency. About 72% of targeted birds in the northern province of Nam Dinh have been vaccinated, but only 38% have been vaccinated in Tien Giang province in the south, where flooding has caused problems, the story said.
In other developments, officials in Finland reported a possible avian flu outbreak in seagulls, but it was probably not a highly pathogenic strain, according to a Reuters report today.
A flu virus was found in sick and dead seagulls in the northern town of Oulou, the report said, but the strain was not identified. Finland shares a border with Russia, where H5N1 avian flu has surfaced in poultry in recent weeks, but not in areas near Finland.
CIDRAP Overview: Avian influenza: agricultural and wildlife considerations