Data from: Beyond Rocky Mountain spotted fever: Investigation of the presence and diversity of spotted fever Rickettsia species in ticks submitted from forestry workers

Ticks present a significant risk to people in the southern United States, particularly those who spend time outdoors, as they can transmit agents that cause various diseases. This study evaluated the risk of exposure to ticks positive for spotted fever group (SFG) Rickettsia species among forestry workers. From 2017 to 2021, forestry workers passively collected ticks during field surveys for the USDA Forest Service's Forest Inventory and Analysis (FIA) program. We screened 1395 ticks for SFG-Rickettsia, including Amblyomma americanum (51.5% positive, N=1,279), A. maculatum (40% positive, N=10), and Dermacentor variabilis (22.6%, N=106). The agent of Rocky Mountain spotted fever, R. rickettsii, was not detected; however, seven different SFG Rickettsia species were identified. Rickettsia amblyommatis was the most common, present in 95.7% of A. americanum ticks. The pathogenic R. parkeri was rarely found in two A. americanum nymphs and two A. maculatum males. Several Rickettsia species, such as R. montanensis, R. monacensis, Candidatus R. andeanae, and R. tamurae subsp. buchneri were identified in D. variabilis. Some of these species are suspected to be pathogenic. Rickettsia-positive ticks were detected year-round, with the highest prevalence in Tennessee and Kentucky, possibly due to larger sample submissions, which may have increased detection rates. Dermacentor variabilis were less likely to be Rickettsia-positive compared to A. americanum. Male ticks were less likely to carry Rickettsia than females and nymphs. The presence of Rickettsia-positive ticks found in this study poses a risk to forestry workers, emphasizing the importance of ongoing surveillance and education to prevent tick-borne infections.

蜱虫对美国南部民众构成显著健康风险，尤其常进行户外活动者，因其可传播多种致病病原体。本研究评估了林业从业者接触斑点热群立克次体（spotted fever group Rickettsia, SFG）阳性蜱虫的暴露风险。2017年至2021年间，林业从业者为美国农业部林务局（USDA Forest Service）的森林资源清查与分析（Forest Inventory and Analysis, FIA）项目开展野外调查期间，被动采集了蜱虫样本。研究团队对1395份蜱虫样本开展了SFG立克次体筛查，样本涵盖美洲钝眼蜱（Amblyomma americanum，阳性率51.5%，N=1279）、美洲花蜱（A. maculatum，阳性率40%，N=10）以及变异革蜱（Dermacentor variabilis，阳性率22.6%，N=106）。未检出落基山斑点热的致病菌立氏立克次体（R. rickettsii），但共鉴定出7种不同的斑点热群立克次体。其中钝眼蜱立克次体（R. amblyommatis）最为常见，在95.7%的美洲钝眼蜱样本中检出。致病性的帕氏立克次体（R. parkeri）仅在2只美洲钝眼蜱若虫以及2只美洲花蜱雄虫中检出。变异革蜱样本中还鉴定出多种立克次体，包括山氏立克次体（R. montanensis）、莫纳科立克次体（R. monacensis）、候选安德安纳立克次体（Candidatus R. andeanae）以及田村立克次体布氏亚种（R. tamurae subsp. buchneri），其中部分物种被怀疑具有致病性。本研究全年均检出携带立克次体的蜱虫，阳性率最高的地区为田纳西州与肯塔基州，这可能与当地提交的样本量更大有关，更高的样本量或提升了检出率。相较于美洲钝眼蜱，变异革蜱的立克次体阳性率更低。雄蜱携带立克次体的概率低于雌蜱与若虫。本研究检出的立克次体阳性蜱虫对林业从业者构成健康风险，这凸显了持续开展监测与教育工作以预防蜱传感染的重要性。