CDC/ACIP [to 9 September 2017]
MMWR News Synopsis for September 7, 2017
:: Update: Increase in Human Infections with Novel Avian Influenza A(H7N9) Viruses During the Fifth Epidemic and Pandemic Preparedness — China, October 1, 2016–August 18, 2017
Avian influenza A(H7N9) viruses remain a pandemic concern. The fifth annual epidemic of Asian Lineage Avian Influenza A(H7N9) Viruses in China is marked by extensive geographic spread in poultry and in humans. The number of human infections reported in the fifth epidemic is almost as many as were reported during the previous four epidemics combined. The increased number of human infections appears to be associated with wider geographic spread and higher prevalence of Asian H7N9 viruses among poultry rather than any increased incidence of poultry-to-human or human-to-human spread. Human infections with Asian H7N9 viruses from poultry are rare, and no efficient or sustained human-to-human transmission has been detected. Among all influenza viruses assessed using CDC’s Influenza Risk Assessment Tool, the Asian H7N9 virus is ranked as the influenza virus with the highest potential pandemic risk. Continued vigilance is important to identify changes in the virus that have epidemiologic implications, such as increased transmission from poultry to humans or transmission between humans.