The nation's leading bird flu experts on Sat 4 Nov 2006 refuted a
report that a new strain of bird flu had emerged in southern China,
published by a foreign publication and widely cited by foreign media
recently. Scientists in Hong Kong and the United States said in a
report released last week that a new strain of bird flu called the
"Fujian-like virus", first isolated in the southern Chinese province
of Fujian in 2005, had become prevalent in the Hong Kong Special
Administrative Region, Laos, Malaysia, & Thailand.

Chen Hualan, director of the National Bird Flu Reference Laboratory
at the Chinese Academy of Agricultural Sciences, rebuked the report,
published in the US-based Proceedings of the National Academy of
Sciences [see ProMED-mail post entitled: Avian influenza, human
(173): new sub-lineage 20061102.3144]  saying its claims "lack
scientific proof".  "The so-called 'Fujian-like virus' is not a new
variant of the virus," she said, "Gene sequence analysis of the virus
shows that it shares high conformity with the H5N1 virus that was
isolated in Hunan when bird flu broke out [there] in early 2004."

Samples from every domestic bird flu outbreak are sent for isolation
and gene sequence analysis at Chen's lab.  Chen said that in 2005 and
2006, the lab had isolated some viruses in waterfowl in southern
China which was reported to the Food and Agriculture Organization
(FAO) and the World Organization for Animal Health (OIE). "These
viruses all remain steady in gene type and there is no marked change
in their biological characteristics," she said.

Chen said there was only one new variant of the virus, which was
isolated in north China's Shanxi Province and the Ningxia Hui
Autonomous Region at the beginning of this year [2006] and has been
reported to the FAO & OIE. Experimental results show that the variant
is weak in triggering disease in mammals, and a new vaccine, which
has been put into use in these areas, has effectively brought it under control.

Chen also defended the effectiveness of China's bird flu vaccine,
saying that it had a good effect, in response to the report's surmise
that the current vaccine was less effective for the "Fujian-like
virus". The report claimed that through the analysis of serum samples
from 76 chickens for signs of antibodies against 3 H5N1 variants,
including the Fujian-like strain, they found almost all of the
samples displayed 2-4 times more antibodies to the other 2 variants
than to the Fujian virus, suggesting that the vaccine given to the
chickens was less effective against that strain.  Chen said that the
evaluation of the vaccine was "not scientific", as where the chickens
were from and whether they had been vaccinated was unknown.

Chen said that since the country launched a strategy of culling and
vaccination to curb bird flu in the latter half of 2005, the number
of bird flu cases has plummeted. Statistics from the Ministry of
Agriculture showed that more than 95 percent of domestic poultry had
been vaccinated from January to October [2006]. 10 cases of bird flu
broke out in poultry populations from January to October in 2006;
there were 50 cases in 2004 and 31 last year.

Shu Yuelong, director of the National Influenza Centre at the Chinese
Centre for Disease Control and Prevention, also refuted the report's
allegation that 5 people in southern China were actually infected by
the new "Fujian-like virus". Shu said that altogether 16 variants of
bird flu viruses have been found in the 20 confirmed cases of human
infections in the Chinese mainland since October 2005, 7 in 2005 and
13 in 2006. "15 out of the 16 variants were isolated from cases in
southern China and they belong to the same gene type," Shu said,
"There is no proof that 5 of them were infected by a new mutated
virus." Shu said that the viruses isolated in South China and
northern China were very different, and also differed a lot with the
virus isolated in Vietnam and Thailand.

Chen Hualan also attacked the report's allegations that the
"Fujian-like virus" was causing a 3rd wave of prevalence of bird flu
in Southeast Asia. "Judging from the actual situation, these
allegations are all subjective and arbitrary surmises," she said.

--
Joseph P.Dudley
<jdudley@eaicorp.com>