Influenza Testing and Variant Influenza A Virus Detection

The 2021 city and county fair season in Wisconsin is quickly approaching. During recent summers, swine exhibitions at agricultural fairs and other direct or indirect exposure to swine have been associated with human infections caused by variant influenza A viruses that include A/H3N2v, A/H1N2v, and A/H1N1v.
Clinicians should consider influenza among patients with acute respiratory illnesses (ARI) who report either direct or indirect exposure to swine. Direct exposure to swine includes showing swine, raising swine, feeding swine, cleaning swine waste, or physically touching swine. Indirect exposure to swine includes visiting a building that houses swine or attending an event where swine are present. Clinicians should also suspect variant influenza in symptomatic patients who have been in close contact with an ill person who had recent swine exposure, or is known to be infected with a variant virus (within 2 meters or approximately 6 feet).