Field epidemiological survey of human granulocytic anaplasmosis in Yiyuan county, Shandong province

ObjectiveTo analyze the risk factors and infection routes of human granulocytic anaplasmosis occurred in Yiyuan county. MethodsThe survey and descriptive analysis were conducted for 34 suspected human granulocytic anaplasmosis cases reported from 2002 to 2006，and the laboratory test was performed for the selected cases. The control group well matched by age, gender and address was selected to conduct 1∶2 case control study. ResultsSingle factor analysis and logistic regression analysis indicated that the frequent forest work (IOR/I=4.4901, 95%ICI/I: 1.4348-14.0518, IP/I0.05), the average work time was more than 1 hour (IOR/I=4.0408, 95%ICI/I: 1.3083-12.4806, IP/I0.05) and livestock shed in residential area (IOR/I=3.3707, 95%ICI/I: 1.2883-8.8191, IP/I0.05) were the risk factors of human granulocytic anaplasmosis in Yiyuan county. ConclusionAccording to the clinical data, field epidemiological survey and case control study, the possible infection routes of human granulocytic anaplasmosis included contacting livestock (especially sheep), forest work and contacting grassland. Further survey and study are needed for human granulocytic anaplasmosis.