Proximal determinants of risk for tularemia outbreaks

兔热病暴发风险的近端决定因素

• 批准号: 6679462
• 负责人: Sam R Telford
• 金额: $ 23.78万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-30 至 2005-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6679462
• 关键词: Carnivora; Francisella tularensis; Lagomorpha; Procyonidae; Rodentias; animal mortality; bacteria infection mechanism; bioterrorism /chemical warfare; clinical research; communicable disease transmission; disease /disorder etiology; disease reservoirs; disease vectors; epizootiology; field study; geographic site; human ecology; human subject; occupational hazard; polymerase chain reaction; questionnaires; sample collection; serology /serodiagnosis; ticks; tularemia; zoonosis

DESCRIPTION (provided by the applicant): Although much is known about the biology of Francisella tularensis, the factors that regulate its natural prevalence remain un-described. We seek to test the 'rule of the incumbent' hypothesis: by analogy with politics, F. tularensis epizootics in the northeastern United States are limited by interactions with a 'ruling' endosymbiotic Francisella sp. (previously classified as Wolbachia sp.) common within tissues of dog ticks, Dermacentor variabilis. The recent outbreak of tularemia on Martha's Vineyard provides a unique opportunity for identifying factors that serve as the basis for increased transmission of this rare infection because sites there appear to be longstanding natural foci of this infection. However, testing this hypothesis requires identification of these natural foci, which may comprise small patches of vegetation; transmission is not homogeneously distributed over the entire 100,000-hectare island. Accordingly, we first seek to identify such natural foci by (1) determining whether striped skunks (Mephitis mephitis) serve as effective sentinels for F. tularensis transmission; and (2) complementing skunk-based predictions by enlisting landscapers and others who are occupationally exposed to tularemia and other tick borne infections to actively report, in real time, the presence of animal carcasses encountered during their work. Natural foci will be definitively confirmed by intensive longitudinal epizootiologic analyses (prevalence of F. tularensis infection in ticks and other potential vector arthropods; evidence of exposure in rodents and other animals). In this manner, we shall accumulate reliable study sites and the preliminary data required for a comprehensive test of the 'rule of the incumbent' hypothesis. In addition, our mapping of risky sites may serve as the basis for local public health measures. We anticipate that the epidemiologic and epizootiologic methods developed or validated during the proposed work may contribute towards enhanced investigations of tularemia outbreaks; new prevention strategies for those at risk of natural or illicit tularemia exposure; enhanced detection of F. tularensis in the environment; and, ultimately, a better understanding of F. tularensis-host interactions.

描述（由申请人提供）：尽管对弗朗西斯氏菌的生物学知之甚少，但调节其自然流行率的因素仍未描述。我们试图检验“现任”假设的“统治”：通过与政治类似，美国东北部的tularensis epizootics受到与“统治”内共生Francisella sp的相互作用的限制。 （以前被归类为Wolbachia sp。）在狗tick虫的组织中常见。最近，关于玛莎葡萄园的Tularemia爆发为识别因素增加了这种罕见感染的基础，这为识别因素提供了独特的机会，因为该地点似乎存在这种感染的长期自然焦点。但是，检验该假设需要鉴定这些天然焦点，这可能包括少量的植被。在整个100,000公顷的岛屿上，传输不是同质分布的。因此，我们首先试图通过（1）确定条纹臭鼬（墨肾炎）是否可以作为f菌的有效哨兵； （2）通过招募园林绿化和其他受到暴露于Tularemia和其他tick感染感染的人的预测，以实时报道他们工作中遇到的动物尸体的存在。自然灶将通过强化的纵向epizootiologic分析（tick和其他潜在的载体节肢动物中的F. tularensis感染率）明确证实。通过这种方式，我们将积累可靠的研究地点以及对“现任”假设的“规则”进行全面检验所需的初步数据。此外，我们对风险地点的映射可以作为当地公共卫生措施的基础。我们预计在拟议的工作期间开发或验证的流行病学和epizootiologic方法可能有助于加强对tularemia爆发的研究。为有天然或非法tulare症风险的人提供新的预防策略；在环境中增强了对tularensis的检测；最终，更好地理解了F. tularensis-host相互作用。