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Liaoning Amantadane Use Signal Major H5N1 Human Outbreak?
Recombinomics Commentary
January 16, 2006
When bird flu began killing chickens across Liaoning province in northeastern China late last year, officials took the preventive step. Without waiting to determine whether the virus had spread among people, they appear to have distributed antiviral drugs to farmers and cullers who might have been exposed to the sick birds.
Northeast Pharmaceutical Group Co., a Liaoning drug company, says it sent five million pills of amantadine, rimantadine and vitamin C to Heishan county's civil affairs department in November. Li Zunjie, office director of the Heishan Health Bureau, says that after bird flu spread to the county, the provincial health department had called on local pharmaceutical companies to donate antiviral drugs. Mr. Li, who doesn't recall how many pills were involved, says he then distributed the drugs to the farmers and cullers.
The above comments on the shipment of major quantities of amantadine and rimantadine to Liaoning province in November coincides with boxun reports of 77 human fatalities in cullers in Liaoning province.
China filed a number of OIE reports describing outbreaks in Jinshou, Fuxin, as well as six towns in Heishan county that involved domestic poultry and wild birds. The OIE reports also indicated three different bird vaccines were used.
The multiple reports and multiple vaccines suggested the outbreaks were hard to control and boxun reports indicated cullers were called in from other provinces and a fatal version of H5N1 spread through the cullers killing 77.
77 deaths would be a record number of fatalities for one region and the shipment of amantadine and rimantadine to the area supports the involvement of H5N1 wild bird flu, which is sensitive to the amantadanes. The large number of pills suggest that a major outbreak among humans may have happened.
Officially, China has only reported one human case in Liaoning Province, but the recent outbreak in Turkey suggests H5N1 can quickly spread over a large area and infect many people.
In Turkey HA S227N has been identified, which would increase the affinity for human receptors. However, all H5N1 wild bird sequences since the May 2005 outbreak at Qinghai Lake have also had PB2 E627K, which allows for more efficient replication in colder temperatures, which may have been the case in Liaoning Province in November.
If the boxun reports are accurate, the human cases in China are being significantly under reported. China has reported 3 cases in Hunan, but most reports only describe 1-2 cases and China has limited official cases to those from whom H5N1 was isolated. These stringent requirements may generate a significant undercount in official cases that would be more extreme than the undercount created by WHO requirements which are frequently not met because of poor sample collection.
A high number of human fatalities in China would be a concern because of the large number of outbreaks linked to migratory birds. These birds will likely carry H5N1 throughout China and into southeast Asia, which may be leading to larger clusters of cases in Indonesia also.
The presence of H5N1 in long rage migratory birds with have PB2 E627K fixed could have catastrophic consequences. The large number of cases and clusters in Turkey are cause for concern. Moreover, if the reports of large numbers of human fatalities in Liaoning in November are accurate, the more lethal human cases of H5N1 infections throughout China would be expected.
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