[Preliminary investigation on reservoir hosts of Borrelia burgdorferi in China].

From 1987 to 1997, the reservoir hosts of Borrelia burdorferi(B.b.) were investigated in 16 provinces, municipalities and autonomous regions of China. Seroepidemiological findings indicated that cattle, sheep, dogs and rats from forest areas had a high antibody titer for B.b. (B31) with positive rates of 18.18%-32.61%, 17.12%-61.21%, 38.50-60.00% and 41.18%-86.05% respectively. Using BSK medium, 20 strains of B.b. were isolated from Apodemus agrarius, Clethrionomys rufocanus, Eutamias sibiricus, Rattus coxingi, Rattus norvegicus, Rattus edwardsi, Rattus confucianus, Rattus fulvescens and Caprolagus sinensis. These spirochetal strains were identified as B.b. by indirect immunofluorescence assay using species and genus specific monoclonal antibodies. Vertical transmission of B.b. was confirmed with B.b. isolated from foetuses of Apodemus agrarius and Rattus edwardsi. The results showed that lyme disease spirochetes, B.b., might be naturally maintained in an enzootic cycle by transplacental transmission. Apodemus agrarius and Clethrionomys rufocanus might serve as major reservoir hosts for B.b. in China.