Molecular epidemiological survey of Anaplasma in small mammals in Yunnan province
TANG Li1,2, SHAO Zong-ti1, DUAN Xing-de1, JIANG Jia-fu3, JIA Na3, ZHANG Yun1, HE Zhi-hai1,2, LI Yu-qiong1, LIU Zheng-xiang1, PU En-nian1, CHEN Xing1,2, LIU Hong-bo3, JIANG Bao-gui3, GAO Zi-hou1, DU Chun-hong1
1.Yunnan Institute of Endemic Disease Control and Prevention,Dali 671000,China; 2.School of Public Health, Dali University, Dali 671000, Yunnan Province, China; 3.State Key Laboratory of pathogen and Biosecurity,Beijing Institute of Micobiology and Epidemiology,Beijing 100071,China
Abstract:To investigate the species and epidemic situation of Anaplasma infecting small mammals and survey the threat to the human and domestic health in Yunnan Province and provide scientific evidence for developing control measures. A total of 2 251 small mammals belonging to 52 species, 26 genera, 9 families from 4 orders were captured in 130 sample locations in 22 counties of Yunnan Province. DNA was extracted from spleen tissue. A nested PCR to target partial sequences(660 bp) within the 16S rRNA gene of Anaplasma was done by using universal primers of Anaplasma. Anaplasma species was identified by Blast program and phylogenetic tree. Epidemiological significance was analyzed by knowing Anaplasma species and sample information. 27 samples were infected with Anaplasma with the infection rate of 1.20%, of which 23 were infected with Anaplasma phagocytophilum, 4 were infected with Anaplasma sp. These positive small mammals belonging to 12 species,7 genera and 6 families from 3 orders were S. fusicaudus (50.00%), S.cylindricauda (12.50%), D.pernyi (8.33%), O. thibetana (5.66%), P.leucurus (5.41%), E.custos (4.00%), N.confucianus (3.74%), R. nitidus (3.57%), R. brunneusculus (2.20%), A.latronum (1.85%), A.draco (1.30%) and R.tanezumi (0.69%). The positive samples belonging to 12 species, 7 genera, 6 families from 3 orders originated from 5 counties. The prevalence of Anaplasma in male small mammals was significantly higher than that in the female mammals. The prevalence of A.phagocytophilum in small mammals at the altitude classes of >2 500 meters were highest. However, there was no significant difference in prevalence of A.phagocytophilum between different mammal genders, as well as ages.Conclusion Many species of small mammals in some counties of Yunnan Province were infected with A.phagocytophilum, which threaten human health and stock raising development. It is necessary to investigate infection rate of Anaplasma in ticks, humans and other host animals.