H7N9 Avian Influenza Update

As of May 9, 2013, there were 131 confirmed cases of the new bird flu H7N9 in China. Of these, 32 patients have died. It appears that the number of reported new cases is declining. There is speculations that this decline may be due to the containment measures reportedly taken by Chinese authorities, including closing live bird markets, where the risk of exposure to any bird flu viruses can be high. However, it is known that bird flu viruses can be seasonal like human viruses, so that the change from winter to summer, when there are fewer bird flu viruses circulating in China may also contribute to fewer human cases. So, H7N9 bird flu activity in poultry or other birds may be declining and with it the chances for human exposures and resulting human infections. If this is the case, H7N9 activity may return again when the weather turns cooler.

There has been no substantial change in what is currently known about the source of this virus. Infected poultry or contaminated environments like live poultry markets seem to be the source of most but not all infections. There is still no evidence of ongoing human-to-human transmission with this virus. No cases have been reported outside of mainland China, except for the one case in Taiwan who was infected while in mainland China.
The World Health Organization has not recommended any travel restrictions, but it would be good practice to avoid visiting any live poultry markets at this time.