Communicable disease threats, 5-11 August 2012, week 32

During the 2012 transmission season of the West Nile virus in Europe, Greece has reported 44 autochthonous cases (24 confirmed, 20 probable). Likewise, Italy notified ECDC about an asymptomatic case of West Nile virus infection in a resident of Venezia province. On 13 July, ECDC updated its Rapid risk assessment on West Nile virus infection in the European Union, which concluded that more cases should be expected.

Six autochthonous cases of Plasmodium vivax malaria have been reported from Greece since June 2012. According to the Greek authorities, active screening of neighbours and seasonal immigrants is being carried out to detect malarial infection, and vector control measures are being implemented.

Since July 2012, 152 cases of the variant influenza A(H3N2) virus (A(H3N2)v) have been detected in the US. No human-to-human transmission has been determined among these recent cases. These reports come following detection of 13 isolates with influenza A(H3N2)v in the US between August 2011 and April 2012. The recent increase in the number of cases is consistent with the conclusions of the ECDC risk assessment published in November 2011 and updated in December 2011.