Aug 27, 2008 (CIDRAP News) – The United Nations Food and Agriculture Organization (FAO) said today that the recent novel H1N1 influenza outbreak in turkeys in Chile points up the possibility of poultry outbreaks elsewhere, increasing the risk of H1N1 mixing with the more deadly H5N1 avian flu virus.
Chilean authorities told the World Organization for Animal Health (OIE) on Aug 21 that the H1N1 virus was found on two turkey farms near the seaport of Valparaiso. The turkeys' egg production dropped, but no increase in mortality was seen. A later report from Chilean officials said the virus was identical to the one circulating among humans in Chile.
The FAO said the discovery does not pose any immediate threat to human health, and turkey meat can still be sold after veterinary inspection and hygienic processing. But it does raise the possibility of outbreaks on poultry farms elsewhere in the world, the agency said.
The FAO stated that the novel H1N1 strain is highly contagious but "no more deadly than common seasonal flu viruses. However, it could theoretically become more dangerous if it adds virulence by combining with H5N1, commonly known as bird flu, which is far more deadly but harder to pass along among humans."
"Chile does not have H5N1 flu. In southeast Asia where there is a lot of the virus circulating in poultry, the introduction of H1N1 in these populations would be of a greater concern," said Juan Lubroth, the FAO's interim chief veterinary officer, in the agency's press release.
In an Aug 23 report to ProMED, the reporting service of the International Society for Infectious Diseases, a Chilean health official said the Chilean finding marked the first known case of transmission of the novel H1N1 virus from humans to birds. (The Aug 21 report by Chile to the OIE said the turkeys had been exposed to people with respiratory symptoms.)
The Chilean official, Julio Garcia Moreno, MD, MSc, of Chile's Institute of Public Health, also remarked on the risk of an H1N1 reassortment with H5N1. "This is a concern vis-a-vis the possibility that this may happen in Asia or Africa under the conditions of co-infection with H5N1 virus," he wrote.
Another animal health expert, Dr. Les Sims of Asia Pacific Veterinary Information Services in Australia, told CIDRAP News recently that he regarded the chance of an H1N1-H5N1 reassortment event as low.
Sims, who is a consultant to the FAO, said he wasn't surprised by the news of the turkey outbreak. He added, "It was always a possibility that turkeys would be susceptible, albeit one that I had not considered as a threat in Asia given the limited number of turkeys reared in this part of the world.
"We cannot rule out the possibility of an H5N1 and H1N1 reassortant emerging, but my assessment is that the probability of such an event occurring remains low," Sims said.
The FAO statement said the risk of reassortment is one of the reasons FAO encourages improved monitoring of animal health and good farming practices, including protecting farm workers if animals are sick and not allowing sick workers near animals.
The agency noted that Chile is the fourth country investigating the spillover of the 2009 H1N1 virus from farm workers into animals. Swine have been infected in Canada, Argentina, and, most recently, Australia.
Aug 27 FAO press release
Aug 21 Chilean report to OIE
Aug 23 ProMED report