Agencies to seek accord on naming of H5N1 strains

Dec 11, 2006 (CIDRAP News) – International health officials who met with Chinese health experts last week said the dispute over the "Fujian-like" strain of H5N1 avian influenza reflects confusion over names and vowed to seek an agreement on terminology for the various H5N1 subgroups.

The meeting in Beijing came a few weeks after US and Hong Kong scientists reported in a medical journal that the Fujian-like strain had emerged as the predominant H5N1 strain in southern China in the past year and caused increased poultry outbreaks. Chinese authorities rejected the report, saying the strain did not exist as a distinct subgroup.

A postmeeting statement from the World Health Organization (WHO), United Nations Food and Agriculture Organization (FAO), and World Organization for Animal Health (OIE) affirmed the existence of the Fujian-like strain, but said it has been called several different names.

Participants agreed that "a number of significant H5N1 virus groups have been identified from poultry and wild birds in China since 2004," the statement said. "One such identified group of viruses has been termed differently by several groups. Terms include the 'waterfowl clade', 'clade 2.3', and 'Fujian-like'."

The statement also said, "It was agreed there is a need for a shared understanding and a common nomenclature for influenza A(H5N1) groups and that some of the recent confusion about the avian influenza situation in China resulted from multiple terms used to describe the same virus groups.

"FAO/OIE/WHO will establish an international working group including Chinese experts to develop global consensus on terminology to be used when describing different influenza A(H5N1) virus groups."

According to a Reuters report, the WHO's David Heymann told reporters after the meeting, "It's very important that naming of viruses is done in a way that doesn't stigmatize countries, that doesn't stigmatize regions and doesn't stigmatize individual people." Heymann is the WHO's assistant director-general for communicable diseases.

Media reports on the meeting said Chinese experts didn't deny the existence of the Fujian-like strain but did take exception to the name. According to a Canadian Press (CP) report, Chinese officials said the Hong Kong–US researchers had renamed a known H5N1 subgroup that some other authorities called Anhui-like, Anhui being another Chinese province.

The FAO-OIE-WHO statement affirmed some aspects of the Hong Kong–US researchers' report, which was published by the Proceedings of the National Academy of Sciences. For example, the statement said information presented at the meeting indicated that the Fujian-like strain has grown more common in parts of southern China since 2005 and has been found in poultry in Laos and Malaysia this year.

In addition, the statement said, "This virus group has been documented to cause some human infection in 2005 and 2006 in China," as the Hong Kong–US researchers had said.

But contrary to another possibility the researchers have suggested, "There is no evidence to date to link the emergence of this virus group with use of poultry influenza vaccination in China."

The statement affirmed that vaccination can control H5N1 in poultry, provided that vaccines are of high quality and well matched to circulating viruses and that vaccination coverage is adequate.

"China has recently strengthened poultry surveillance to include serological (antibody) and virus surveillance as well as surveillance for disease outbreaks," the statement added. With the increased surveillance, China is now publishing data monthly on the Ministry of Agriculture Web site, rather than annually, news services reported.

China has been criticized for sharing too little data on the H5N1 virus and too few samples. Last month the country promised to provide samples to the WHO.

Keiji Fukuda, coordinator of the WHO global influenza program, said all participants at the meeting agreed that sharing information and virus samples "is critical for the defense of everybody," according to Reuters.

The FAO-OIE-WHO statement said there has been no evidence that the Fujian-like strain is more transmissible to humans than other H5N1 viruses and no evidence that it has sparked human-to-human transmission.

See also:

Nov 10 CIDRAP News story "Chinese promise H5N1 samples, deny claim of new strain"

Nov 3 CIDRAP News story "Study says new H5N1 strain pervades southern China"

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