Autumn has arrived. So has H7N9 (and H7N2).

Influenza is a seasonal infection. Migratory birds on their way to warmer climes drop their faeces during their flight onto pigs and humans alike.

It has been a little while since the last official case of Influenza H7H9 was reported but now, with autumn approaching in China, a new case has emerged. This is the first new confirmed case of human infection with avian influenza H7N9 virus since 11 August 2013.

To date, WHO has been informed of a total of 136 laboratory-confirmed human cases with avian influenza A(H7N9) virus infection including 45 deaths.

In other, related news: a highly pathogenic strain of Influenza H7N2 has been identified in poultry in Australia. The decision has been made to cull 400,000 birds and destroy upwards of 3,000,000 eggs.

Although human infection with H7 avian influenza is not unknown, it has been a rather rare occurence and the risk of infection in humans from these avian viruses is generally considered low. The exception to this rule is of cource the recently emerged H7N9 virus in China, which has proven unexpectedly pathogenic in humans.