Sero-epidemiology of Lyme disease in an endemic area in China.

A sero-epidemiological investigation on Lyme disease was carried out in a forestry center of Hailin County, Heilongjiang Province, China. A total of 381 participants including forestry workers and their dependents completed questionnaires and had blood samples taken for detection of antibody against Borrelia burgdorferi by indirect immunofluorescent assay. Of 381 participants, 250 (65.6%) had a history of tick bites between May and July, 1987, and 379 (99.5%) at some time in the past, 56 (14.7%) developed erythema migrans at the site of tick attachment, 138 (36.2%) had late manifestations of Lyme disease, and 101 (26.2%) were seropositive. There was a significant difference in the seropositive rate between the persons with tick bites and those without tick bites in 1987 (P < 0.01). The titers in the older age group (over 30) were slightly higher than those of the younger age group (under 30). No relationship between the prevalence of Lyme manifestations by tick bites and the result of serological test was observed. Further investigations are necessary to assess the actual prevalence and incidence of infections using antigen of Lyme disease borreliae isolated in China.