Department of Civil, Architectural and Environmental Engineering, Drexel University, Philadelphia, PA 19104, USA.
Risk Anal. 2011 Oct;31(10):1610-21. doi: 10.1111/j.1539-6924.2011.01604.x. Epub 2011 Mar 31.
Rickettsia rickettsii is the causative agent of Rocky Mountain spotted fever (RMSF) and is the prototype bacterium in the spotted fever group of rickettsiae, which is found in North, Central, and South America. The bacterium is gram negative and an obligate intracellular pathogen. The disease is transmitted to humans and vertebrate host through tick bites; however, some cases of aerosol transmission also have been reported. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment, it can be fatal. This article develops dose-response models of different routes of exposure for RMSF in primates and humans. The beta-Poisson model provided the best fit to the dose-response data of aerosol-exposed rhesus monkeys, and intradermally inoculated humans (morbidity as end point of response). The average 50% infectious dose among (ID₅₀) exposed human population, N₅₀, is 23 organisms with 95% confidence limits of 1 to 89 organisms. Similarly, ID₁₀ and ID₂₀ are 2.2 and 5.0, respectively. Moreover, the data of aerosol-exposed rhesus monkeys and intradermally inoculated humans could be pooled. This indicates that the dose-response models fitted to different data sets are not significantly different and can be described by the same relationship.
落矶山斑点热（RMSF）的病原体是立克次体立克次体，它是斑点热群立克次体中的原型细菌，存在于北美、中美和南美。该细菌为革兰氏阴性菌，是一种专性细胞内病原体。该疾病通过蜱叮咬传播给人类和脊椎动物宿主；然而，也有一些气溶胶传播的病例报告。在疾病的早期阶段，这种疾病可能难以诊断，如果没有及时和适当的治疗，它可能是致命的。本文为灵长类动物和人类建立了 RMSF 不同暴露途径的剂量-反应模型。β-泊松模型为暴露于气溶胶的恒河猴和皮内接种的人类（以发病率作为反应终点）的剂量-反应数据提供了最佳拟合。暴露于人群中的平均 50%感染剂量（ID₅₀），N₅₀为 23 个生物体，95%置信区间为 1 至 89 个生物体。同样，ID₁₀ 和 ID₂₀ 分别为 2.2 和 5.0。此外，暴露于气溶胶的恒河猴和皮内接种的人类的数据可以合并。这表明拟合不同数据集的剂量-反应模型没有显著差异，可以用相同的关系来描述。
