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H5N1 Cluster in Hunan China Raises More Concerns
Recombinomics Commentary
October 28, 2005
Chen said tests showed a 12-year-old girl who died in southern Hunan province, the site of China's latest bird flu outbreak, was the victim of pneumonia, not bird flu. Her 9-year-old brother also contracted pneumonia and was in a stable condition.
Previous reports said the girl was suspected to have died from bird flu. Chen said the cause of the pneumonia was unclear.
The World Health Organisation (WHO) said on Friday it was seeking information on the two Hunan children.
"We still have no information on suspect cases in China," WHO spokeswoman Maria Cheng told Reuters in Geneva. "We need more clarification because both apparently had been exposed to sick chickens."
The above comments clearly point toward two human infections in Hunan by H5N1 wild bird flu. Although China continues to insist that the cases are not bird flu, they have failed to identify an etiological agent for the two pneumonias. In the absence of an etiological agent to explain the two pneumonias, including one that was fatal, the assumption remains that these are H5N1 cases.
China just filed an OIE report confirming HPAI H5 in Wantang Village that killed chickens and ducks> The children had eaten a sick chicken before developing bird flu symptoms. The older child died and her brother is recovering. Both acute respiratory distress and pneumonia are symptoms of bird flu.
These two cases are cause for concern because they appear to be linked to wild bird flu. China reported three outbreaks in 8 days and the outbreaks created a trail from Mongolia to Inner Mongolia, to Anhui, to Hunan and all isolates were H5N1 or HPAI H5, which is consistent with H5N1 (and all HPAI H5 described in Asia to date have been H5N1).
The number of different versions of H5N1 linked to human disease continues to grow, further suggesting that H5N1 wild bird flu can cause human disease. The H5N1 is rapidly spreading. It has been detected in many countries in Europe and is now entering the Middle East while migrating to Africa. H9N2 in the Middle East can recombine with H5N1 to produce S227N in HA, increasing binding for mammalian receptors. Such recombinant would also likely be able to infect humans.
As wild birds continue to bring new H5N1 sequences into new regions, or regions with endemic H5N1, new recombinants will emerge, generating more divers H5N1's and creating new opportunities for more efficient human-to-human transmission.
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