During early 2017, we conducted a seroepidemiologic investigation for tickborne encephalitis virus among 291 Japan Self-Defense Forces members in Hokkaido. Two (0.7%) tested positive. Neither had clinically apparent symptoms after removing ticks.
Keywords: Japan; Japanese encephalitis virus; Subclinical infection; flaviviruses; neutralizing antibody; seroepidemiologic study; tick-borne encephalitis virus; ticks; vector-borne infections; viruses; zoonoses.