L. major infection: Natural history and determinants of resistance

疫源地主要乳杆菌感染的敏感性/耐药性和自然病史的决定因素包括 与环境和宿主相关的风险因素。我们的长期目标是阐明洛杉矶梅杰的自然历史。 皮肤型利什曼病(CL)宿主相关危险因素的相对重要性 考虑影响暴露的环境因素的混杂效应的出现和严重程度。 具体的假设是，主要乳杆菌感染的自然病程和临床表现 皮肤利什曼病根据过去的传播史和当地生物栖息地的类型而变化。 学习区。宿主相关免疫替代物的保护前利什曼皮肤试验(LSI) 传播可以解释对这种疾病的抗药性，并可以作为疗效标准在 疫苗的现场评价。基于这些观察，项目1的重点是通过 基于前瞻性队列人群的流行病学参数估计和临床研究 描述疾病和传播动态，以提高对自然病史的理解 利什曼原虫主要感染及其影响因素。具体目标是： 1.阐明了大型钩端螺旋体感染的流行病学参数。我们将使用 利什曼宁皮肤试验(LST)及临床观察，CL发生率与无症状感染 (LST+/病变-)在一项为期两年的前瞻性研究中，以确定：I)LST阳性的患病率，II) LST转换率和复发率，III)有症状/无症状感染的发生率，IV) 疾病严重程度的评分，v)复发率，vi)预测价值和保护分数 LST阳性。 2.评价免疫宿主相关因素和环境对自然环境的相对重要性 疾病的病史和临床表现。这些包括LST、细胞毒性免疫反应和抗体 抗沙蝇唾液抗原、水库到聚居区的距离、居住特点和 其组成、社会经济因素及主要致病菌株的致病特性。 3.制定和验证皮肤损伤严重程度和由此产生的疤痕质量的量表。规模 项目包括溃疡的大小、颜色(色素沉着减少、色素沉着、正常皮肤)和身高。

Determinants of susceptibility/resistance and natural history of L. major infection in endemic foci include environmental and host related risk factors. Our long term goal is to elucidate the natural history of L. major infection and to weight the relative importance of host related risk factors of cutaneous leishmaniasis (CL) emergence and severity considering the confounding effect of environmental factors influencing exposure. The specific hypothesis is that the natural history of L. major infection and the clinical expression of cutaneous leishmaniasis varies according to past history of transmission and to the type of biotope in the study area. Host related immunological surrogates of protection other than leishmanin skin test (LSI)prior to transmission might explain resistance to the disesase and might be used as efficacy criteria in the context of vaccines' evaluation in the field. Based on these observations the focus of project 1 is to refine bya prospective cohort population based study the estimation of the epidemetric parameters and clinical description of disease and transmission dynamics to improve the understanding of natural history of Leishmania (L.)major infection and its determinants. The specific aims are to: 1. Elucidate epidemetric parameters of L. major infection. We will use leishmanin skin test (LST) and clinical observations, the incidence of CL versus asymptomatic infection (LST+/lesions-) in a two years prospective study in order to determine: i) the prevalence of LST positivity, ii) the rate of conversion and reversion of LST, iii)the incidence of symptomatic/ asymptomatic infection, iv) the score severity of disease, v) the rate of recurrence, vi) the predictive value and the protection fraction of LST positivity. 2. To evaluate the relative importance of immune host related factors and environmental on the natural history and clinical expression of the disease. These include LST, cytotoxic immune response and antibodies against sand flies' saliva antigens, distance to colonized area by reservoirs, characteristics of dwelling and its compound, socio-economic factors and pathogenic properties of L. major isolates. 3. To develop and validate scales for severity of cutaneous lesions and quality of resulting scars. The scale items include size of the ulcer, color (hypopigmentation, hyperpigmentation, normal skin) and height.