Novel avian influenza A(H7N9) virus outbreak
In March 2013, a novel avian influenza A(H7N9) virus was detected in patients in China. Since then, additional cases from China have been reported. As of January 2018, 1 566 cases have been reported, including 569 deaths. No autochthonous cases have been reported outside China. Most cases are isolated, and sporadic zoonotic transmission from poultry to humans is the most likely explanation for the outbreak. The possibility of humans infected with influenza A(H7N9) returning to the EU/EEA cannot be excluded. However, the risk of the disease spreading in Europe through humans is still considered low, as there is no evidence of sustained human-to-human transmission.
The outbreak shows a seasonal pattern:
- The first wave in spring 2013 resulted in 135 cases (week 7 - 40/2013) .
- The second wave led to 320 cases (week 41 - 40/2014) .
- The third wave caused 223 cases (week 41/2014 - 40/2015).
- The fourth wave caused 120 cases (week 41/2015 - 40/2016).
- The fifth wave resulted in 766 cases (week 41/2016 to 40/2017)
- The sixth wave which started on week 40/2017 has resulted in two cases (as of January 2018). Based on the seasonal pattern of avian influenza (H7N9) viruses, more cases are expected as the influenza activity increases during the winter months.
ECDC main outputs:
- ECDC and the European Food Safety Authority (EFSA) are publishing a joint report quarterly which provide an update of the developments of zoonotic avian influenza viruses in EU/EEA and worldwide, in particular with a view to describe the evolution of virus spread from certain regions towards the EU.
- A map showing the distribution of confirmed A(H7N9) human cases by place of reporting is available on the ECDC website.
- New cases and/or rapid assessments are reported in the ECDC Communicable Disease Threats Report; the weekly bulletin for epidemiologists and health professionals on active public health threats.
- ECDC has published rapid risk assessment on 3 July 2017, addressing the genetic evolution of influenza A(H7N9) virus in China and the implications for public health.