Rare positive laboratory tests for the presence of influenza virus A/H1N1--2009 in May, June, July, 2011, in the districts of Kosice I-IV and surroundings of Kosice in the Slovak Republic.

Influenza illnesses and positive laboratory tests for the presence of influenza virus in recent years in the districts of Kosice I-IV and surroundings have only occurred during the winter season. In May to July 2010 only one positive laboratory test for the presence of influenza virus A/H1N1-2009 was reported. In 2011, during the same period, a total of 29 positive laboratory tests recorded the presence of influenza virus A/ H1N1-2009 in individuals with typical clinical symptoms of influenza. Of 29 clinical cases, 27 were diagnosed as influenza and 2 as SARI; 4 cases involved children.