October (selective round-up)

October ends with Thailand seeing its twentieth case of bird flu, a 50 year old woman who lived on the northern outskirts of Bangkok and reportedly had helped her husband clean a chicken coop that had been occupied by infected birds (AP) She is in stable condition and said to be improving. Her husband is asymptomatic but under quarantine (Reuters). Two other cases have also occurred this month in Thailand, a 48 year old male who died after handling his neighbors' sick chickens and the man's 7 year old son, who also was reported to have handled the birds. The boy, who was treated with Tamiflu early on, is recovering. Vietnam also has reported four suspect cases this month, two of whom have died (Reuters). Indonesia also reported several more cases, bringing the confirmed total to seven of whom four have been fatal. However there are many more suspect cases (the exact number is in dispute, so the numer seven is a very conservative lower bound. Finally, The deaths of a 12 year old Chinese girl and her 9 year old brother, while declared negative for H5N1 by Chinese authorities, is still under suspicion by WHO, who has asked for additional information to substantiate the negative result. The suspicious cases occur in the setting of three new outbreaks in bird flocks in China.

Thus the human cases continue to be reported from Asia, South Asia and Southeast Asia. This is also the area where the H5N1 virus has become endemic in birds and where WHO believes a pandemic is most likely to develop. Because of the vast number of viral "bioreactors" (birds, other livestock and humans) living closely together in this region, this is a reasonable (but not necessary) proposition.

But the panzootic (pandemic in animals) also extended itself this month, finally reaching Europe.

Outbreaks of avian influenza H5N1 have now been confirmed in five countries either by the World Organisation for Animal Health (OIE) or national government agencies in the WHO European region: Croatia, Kazakhstan, Romania, the Russian Federation and Turkey. In addition to this, avian influenza H5N1 has been confirmed in an imported parrot in the United Kingdom. There are now numerous further outbreaks of disease in birds under investigation in several European countries.

Since the occurrence of outbreaks of highly pathogenic avian influenza H5N1 virus in migratory birds, the risk of transmission to domestic birds has increased. Surveillance in wild birds has thus become a priority and the European Union has made guidelines available. It is likely that migratory birds are responsible for the introduction of H5N1 in the European region, as the viruses from outbreaks in Kazakhstan, Romania and Turkey are phylogenetically almost identical to the virus that caused the wild bird die-off at Lake Qinghai in China in May 2005. (from WHO, citations omitted)

WHO is at pains to emphasize (correctly) this is not evidence of the start of a human pandemic, although the increased range and number of infections might add to the risk. This is correct, of course. But it does mean that preparations and surveillance need to be ramped up everywhere. The appearance of H5N1 in the parrot in the UK also sparked new import bans in the European Union:

The European Commission has banned the import of live birds into the European Union (EU) from outside countries. The ban covers captive live birds except poultry imported for commercial purposes. No more than five birds will be allowed into the EU with their owners, provided they have undergone a 30 day quarantine, been vaccinated against avian influenza, or have tested negative for avian influenza in a 10 day isolation period before movement. However, birds may be accompanied by their owners between the EU and Norway, Switzerland, Liechtenstein Andorra, Iceland, Greenland, Faeroe Islands and San Marino. Birds may also be moved between approved zoos and similar institutions. (Eurosurveillance Weekly)

All in all, not a good month on the bird flu front. But it could have been worse. And it likely will be.