Investigation of anaplasmosis in Yiyuan County, Shandong Province, China

Objective: To investigate the situation of anaplasmosis in Yiyuan county, Shandong Province. Methods: A total of 26 blood samples from febrile patients suspected of anaplasmosis, 48 blood samples from healthy farmers, 8 from dogs, and 10 from goats and 170 ticks were collected in the same area during 2005-2007, and detected by serological and molecular methods. Results: Eight confirmed cases and 6 probable cases were determined using serologic and molecular methods. The seroprevalence of Anaplasma phagocytophilum (A. phagocytophilum) was 26.7% in healthy cases. Nine out of 10 sheep samples and 7 out of 8 dog samples reacted positively to the A. phagocytophilum antigen. PCR amplification and sequencing of the 16SrRNA of A. phagocytophilum gene showed that some samples from patients, goats and ticks were 100% identical. The seroprevalence of Rickettsia typhi was 22.9%, Orientia tsutsugamushi 6.3%, Rickettsia sibirica 27.1%, Coxiella burnetii 18.8%, Bartonella henselae 31.3%, and Borrelia burgdorferi 41.6%. Conclusions: It is important to make differential diagnosis of febrile patients and to apply treatment with specific antibiotics. It is needed to enforce essential prevention and control measures including tick control and to improve sanitation conditions.