Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762, USA.
Vector Borne Zoonotic Dis. 2011 Apr;11(4):439-42. doi: 10.1089/vbz.2009.0221. Epub 2010 Sep 16.
Because tick-borne diseases are becoming increasingly important throughout the world, monitoring their causative agents in wildlife may serve as a useful indicator of potential human exposure. We assessed the presence of known and putative zoonotic, tick-borne agents in four wildlife species in Mississippi. Animals were tested for exposure to or infection with Ehrlichia chaffeensis, Ehrlichia ewingii, Borrelia lonestari, Rickettsia spp., Anaplasma phagocytophilum, and Francisella tularensis. Whole blood and serum were tested from white-tailed deer (WTD; Odocoileus virginianus) and feral swine (Sus scrofa); serum was tested from raccoons (Procyon lotor) and opossums (Didelphis virginiana). We used polymerase chain reaction to detect all agents in blood, whereas an indirect fluorescent antibody assay was used to detect antibodies to E. chaffeensis, B. lonestari, and Rickettsia parkeri (spotted fever group rickettsiae) antigens in serum. Molecular evidence of infection with E. chaffeensis, B. lonestari, and An. phagocytophilum was detected only in WTD. Antibodies to E. chaffeensis antigen were detected in 43.9% of WTD, 32.8% of swine, 42.1% of raccoons, and 15.8% of opossums. Serologic evidence of exposure to B. lonestari antigen was found in 19.3% of WTD, 6.9% of swine, and 5.3% of raccoons, but not in opossums. Interestingly, the percent of animals with antibodies reactive to spotted fever group rickettsiae (R. parkeri antigen) was highest in raccoons (73.7%) and opossums (57.9%). These results support the role of WTD as reservoirs for E. chaffeensis, B. lonestari, and An. phagocytophilum, as well as provide additional evidence for exposure of raccoons and opossums to E. chaffeensis. Finally, we provide new data that feral swine may have antibodies to these agents. Thus, in general, these four wildlife species are exposed to tick-borne disease agents in Mississippi, suggesting that ticks carry and have the potential to transmit the agents to humans in the state.
由于蜱传疾病在全球范围内变得越来越重要，因此监测野生动物中的病原体可能成为潜在人类暴露的有用指标。我们评估了密西西比州四种野生动物物种中已知和推测的人畜共患、蜱传病原体的存在情况。对白尾鹿（Odocoileus virginianus）和野猪（Sus scrofa）进行了全血和血清检测；对浣熊（Procyon lotor）和负鼠（Didelphis virginiana）进行了血清检测。我们使用聚合酶链反应检测血液中的所有病原体，而间接荧光抗体检测用于检测血清中 E. chaffeensis、B. lonestari 和 Rickettsia parkeri（斑点热组立克次体）抗原的抗体。仅在白尾鹿中检测到 E. chaffeensis、B. lonestari 和 An. phagocytophilum 感染的分子证据。在 43.9%的白尾鹿、32.8%的野猪、42.1%的浣熊和 15.8%的负鼠中检测到针对 E. chaffeensis 抗原的抗体。在 19.3%的白尾鹿、6.9%的野猪和 5.3%的浣熊中发现了对 B. lonestari 抗原的暴露血清学证据，但在负鼠中未发现。有趣的是，对斑点热组立克次体（R. parkeri 抗原）有反应的动物百分比在浣熊（73.7%）和负鼠（57.9%）中最高。这些结果支持白尾鹿作为 E. chaffeensis、B. lonestari 和 An. phagocytophilum 的储存宿主的作用，并为浣熊和负鼠接触 E. chaffeensis 提供了额外的证据。最后，我们提供了野猪可能对这些病原体产生抗体的新数据。因此，一般来说，这四种野生动物在密西西比州都接触到了蜱传疾病病原体，这表明这些州的蜱携带并有可能将病原体传播给人类。
