Distribution and prevalence of Mermet virus infections in the central United States.

Tests were run on 3,198 bird sera for neutralizing antibody of Mermet virus. The birds were mostly House Sparrows (Passer domesticus) captured in the central U.S. Antibody was detected in birds from Texas, Mississippi, Tennessee, Ohio, Indiana, Illinois, and Wisconsin, but not Kentucky or Missouri. Antibody prevalence differed by location and between years in similar locations. These results confirmed the widespread activity of Mermet virus in the central U.S., suggested irregular activity of the virus, and provided the first evidence that Mermet virus activity occurs in Mississippi, Indiana, and Wisconsin. No antibody to Mermet virus was found in paired sera from 966 humans with suspected arboviral infection.