Swine-origin triple reassortant influenza A(H3N2) viruses in North America

Risk assessment

ECDC published an update of its previous rapid risk assessment on Swine-origin triple reassortant influenza A(H3N2) viruses in North America. This rapid risk assessment updates that of 29 November 2011, with a focus on the epidemiological information and a report on progress made to address the diagnostic needs in the European Union that will enable detection of these new viruses.

Executive Summary

Today ECDC published an update of its previous rapid risk assessment on Swine-origin triple reassortant influenza A(H3N2) viruses in North America.

Centers for Disease Control and Prevention (CDC) has reported recent infections in children in North America with a swine-origin triple reassortant influenza A(H3N2) virus that includes a genetic component from the pandemic 2009 virus, and with probable human-to-human transmission with these viruses. As of 9 December, eleven cases have been reported in five US states.

The conclusions and recommendations of the ECDC rapid risk Assessment of 29 November remain valid.