In April 2009, influenza A(H1N1)pdm09 virus infection was confirmed in a person who had been symptomatic while traveling on a commercial flight from Mexico to the United Kingdom. Retrospective public health investigation and contact tracing led to the identification of 8 additional confirmed cases among passengers and community contacts of passengers.
Keywords: Mexico; United Kingdom; aircraft passengers; contact tracing; in-flight exposure; infectious disease; influenza; influenza A(H1N1)pdm09; international flights; pandemic; swine flu; transmission; viruses.