We assessed IgM detection in Zika patients from the 2016 outbreak in Miami-Dade County, Florida, USA. Of those with positive or equivocal IgM after 12-19 months, 87% (26/30) had IgM 6 months later. In a survival analysis, ≈76% had IgM at 25 months. Zika virus IgM persists for years, complicating serologic diagnosis.
Keywords: Florida; IgM; IgM antibody capture ELISA; MAC-ELISA; Miami-Dade County; United States; Zika virus; antibody persistence; antibody survival; flaviviruses; immunoglobulin M; mosquitoborne viruses; vector-borne infections; viruses.