Two new cases of H7N9 reported in China

China reported two new cases of H7N9 infection to the World Health Organization in October, according to a recent update from the U.S. Centers for Disease Control and Prevention.

The WHO posted the information about the two cases on October 16 and October 24. The two cases were the first new H7N9 cases reported since August 11. The two additional cases bring the total number of reported cases to 137, including 45 deaths.

The most recent H7N9 case reportedly occurred in a farmer who had contact with live poultry in China. The infection suggests that exposure to infected birds is still the main source of infection with the virus. There is no evidence of sustained human-to-human transmission with the virus.

Evidence suggests that there is a seasonal pattern to the circulation of avian influenza viruses, with activity dropping in warmer seasons and rising in cooler weather. Such a pattern suggests that H7N9 activity among birds and humans could rise again in China when the weather turns colder. While it is likely H7N9 cases will continue to be detected in China during the winter, it is not possible to determine how many cases there will be.

The U.S. government is continuing its preparedness efforts along with global health partners. The CDC did not change the risk assessment for H7N9 in the U.S. as part of its recent update.