Questionnaire surveys of cases of tick bite and Lyme borreliosis in hunters in Hokkaido with reference to detection of anti-Borrelia burgdorferi antibody.

An epidemic of Lyme borreliosis on Hokkaido island, Japan, was surveyed by questionnaire in 587 hunters. The 308 returns (52.4%) revealed episodes of tick bite (usually 2 or more) in 210 cases. Skin rashes appeared in 164 cases. Associated itching, pain, etc., but not skin rash, were more frequent after 2 or more tick bite. Previous determinations of anti-Borrelia burgdorferi antibody titers in these subjects and in controls suggested an association with outdoor activities other than hunting, and among 33 cases of dermatological symptoms and 23 of articular symptoms, 4 and 2, respectively, were antibody-positive. Most of these antibody-positive subjects had suffered tick bite at least twice, but had had no antibiotic treatment. Three subjects with joint disorders were antibody-positive. These findings suggested that the many hunters exposed to Borrelia burgdorferi frequently carried latent infections, and that some had latent form of arthritis, dermatitis and other disorders.