- Authorities also haven't responded to a WHO request to
be allowed to visit the Xinjiang region in China's northwest, where there
have been reports of a bird flu outbreak along the border with Kazakhstan,
said Roy Wadia, a spokesman for WHO's Beijing office.
- Chinese authorities have yet to release samples gathered
in the western province of Qinghai, where at least 6,000 migratory birds
have died, Wadia said.
- "It would be useful if information on the virus
was shared with the international agencies concerning bird flu, or if it
were deposited at gene banks as per the usual procedures in these cases,"
- China's Ministry of Agriculture didn't immediately respond
Wednesday to requests for comment.
- China's failure to respond to foreign appeals for cooperation
has prompted fears that the outbreak might be bigger and more dangerous
- The above comments add considerable weight to concerns
that there is a raging human pandemic in China. China has been the epicenter
of the unprecedented H5N1 outbreak in 2004. H5N1 was reported throughout
China and most adjacent countries. The reported human cases were in Vietnam
and Thailand. In 2005 the human cases were initially concentrated in Vietnam
- However, the demographics of the outbreak in Vietnam
suggested a less lethal but more transmissible variant was affecting northern
Vietnam. Although these cases had been laboratory confirmed, WHO refused
to acknowledge the widespread human-to-human transmission. The first sequences
of 2005 were recently made public, and these new sequences clearly show
a China connection, with sequences found in Guangdong and Yunnan province.
Today fatal human H5N1 was confirmed in Indonesia in suburban Jakarta,
where H5N1 was also detected in asymptomatic swine. The swine sequences
also pointed toward a Yunnan origin.
- The sequences of the H5N1 provide valuable clues on the
origin of infections. A large database was generated using 2004 isolates
and additional 2005 isolates have been deposited at GenBank, although two
weeks after publication, GenBank has still not released these sequences.
- The description of the sequences however, has been published
and they also show links to earlier sequences from Shantou and Hong Kong.
The Nature paper also described 2005 H5N1 sequences from Yunnan, Hunan,
and Fujian Province in addition to Shantou in Guangdong Provicince. The
Qinghai sequences also have a polymorphism in PB2 (E627K), which had previously
been limited to human flu isolates. The presence in H5N1 was limited to
brain isolates from experimental mice, or severe, usually fatal, cases
in humans, dating back to the 1997 outbreak.
- The H5N1 in Qinghai is unusually severe in migratory
birds, which is why it is critical to obtain additional sequence information
on the birds before they disperse throughout Asia and Europe. These sequences
can help identify the genetic changes, which are required to produce more
specific probes for detecting H5N1 and designing more specific vaccines.
- Boxun reports indicate the birds at Qinghai Lake are
infected with several versions of H5N1, which leads to new reassortants
and recombinants. The Qinghai isolates are already reassortants, with
three genes related to Shantou isolates and five related to a Hong Kong
isolate. The E627K indicates they are also recombinants and dual infections
will generate new recombinants.
- The withholding of the sequence data is an ominous sign.
Boxun reports indicate China has an active avian influenza program and
will certainly collect samples and sequences from Qinghai lake, in addition
to the sequences from the Xinjiang outbreaks. Failure to share this information
adds to speculation of a widespread cover-up of human cases. Boxun reports
detailed human cases in Qinghai and the description of the 10 strains indicates
8 infect humans.
- China has never reported a human H5N1 case although fatal
human cases in Vietnam, Thailand, Cambodia, and Indonesia all have genetic
links to China.
- It appears increasingly likely that an unreported flu
pandemic is well underway in China.