Patient with Influenza A(H9N2) in Hong Kong

With reports of new and recurring infections with different subtypes of the Influenza A virus each passing month, China looks more like a boiling cauldron than a tranquil mixing vessel. Just two weeks ago we reported about a fatal case of Influenza A(H10N8) and now the virus has appeared in Hong Kong with an unusual return of Influenza A(H9N2) [Press release here].

Again, the patient is an elderly man with underlying illnesses but this time had no known recent contact with poultry, consumption of undercooked poultry, or contact with patients.

Infection with Influenza A(H9N2) is not unheard of but a rather rare occurrence: in the past 15 years it has been reported only a handful of times, including in Hong Kong in 1999 (two cases), 2003 (one case) and 2007 (one case). Several additional human H9N2 virus infections were reported from China in 1998-99. More recently, in 2011 Bangladesh detected an infected patient.

The patients of these rare and sporadic human cases, generally experience mild respiratory tract infections with a mild fever.