Objective: To investigate the endemic area of Lyme disease in Shandong province.
Methods: An investigation on endemic Lyme disease was conducted by means of serological and etiological methods in Shandong province from 1992 to 1999.
Results: Of 1919 forestry residents, 120 residents had a significant antibody titer against Borolo burgdorferi strain B(31). The prevalance rate of Lyme disease was 6.25%. Haemaphysalis longicornis was a prevailing species of Ixodidae in the region. Spirochetes were observed in the midguts of 50 H. longicornis in this area by direct fluorescence antibody method. The overall positive rate was 12.0% (6/50). Two strains (TSH(1), TSH(3)) of spirochetes were isolated from H. longicornis. Both TSH(1) and TSH(3) were positively responded to McAb H(5332) and H(9724), but negatively to H(6831). Spirochetes were observed in the kidneys of 46 Rattus in this area by direct fluorescence antibody method with a positive rate of 13.26% (6/46).
Conclusion: It was the first time that the mountainous areas in Shandong province was confirmed endemic areas of Lyme disease.