Maine CDC Health Advisory
October 21, 2020
Flavivirus Case in a Maine Resident
Maine CDC identified a human case of neuroinvasive Flavivirus infection in an adult who resides in Cumberland County. The individual became ill in early September and is currently hospitalized. Serum samples collected September 5th and September 13th tested positive for West Nile virus (WNV) antibodies at a commercial laboratory. Per established protocols, Maine's Health and Environmental Testing Laboratory (HETL) sent the samples to the U.S. CDC for further confirmation. Plaque reduction neutralization test (PRNT) testing results from the U.S. CDC indicated evidence of cross-reactive Saint Louis Encephalitis virus (SLEV) and WNV flavivirus neutralization antibodies, although the specific virus could not be identified. This is the first identification of a flavivirus in a Maine resident since 2018.