Indoor Allergens And Asthma

我们的哮喘研究项目包括暴露评估和预防两部分，重点关注暴露于常见室内过敏原与哮喘患病率/发病率之间的关系。美国国家过敏原调查（National Allergen Survey）是一项关于美国房屋地板和床上用品粉尘中过敏原类型和水平的研究，是第一个提供美国人口中过敏原暴露估计的研究。它包括全国75个主要抽样单位的831个家庭。主要终点是测量尘螨，蟑螂，猫，狗，小鼠，大鼠和真菌过敏原水平，以及从调查家庭的一系列地点收集的粉尘样本中的内毒素。尘螨过敏原分析的结果表明，大约24%的美国家庭的床含有bb10微克尘螨过敏原/克粉尘（先前与症状性哮喘相关），大约46%的美国家庭的床含有>2微克尘螨过敏原/克粉尘（先前与尘螨过敏原致敏相关）。在老房子、非西部地区的房子、低收入家庭和湿度较高的卧室里，床上有高尘螨过敏原水平的可能性更大。狗和猫的过敏原在美国家庭中普遍存在。在室内有狗和/或猫的家庭中，这一水平更高；然而，在没有室内宠物的家庭中，平均过敏原浓度仍然远远高于过敏致敏和疾病的建议阈值。在大约82%的美国家庭中检测到小鼠过敏原，22%的家庭的水平超过了建议的感知阈值。在高层公寓、活动房屋、老旧房屋、低收入家庭、报告有啮齿动物或蟑螂问题的家庭，以及用拖地而不是吸尘的家庭，厨房里老鼠过敏原含量较高的可能性更大。这项具有全国代表性的调查(a)提供了美国人口室内过敏原暴露的当前估计，(b)建立了一个数据库，可用于刺激未来试图将过敏原暴露与疾病结果联系起来的研究，(c)提供了一个基线，可作为未来过敏原调查的参考点，(d)促进了对过敏原负担的地区、种族、社会经济和住房特征差异的评估。我们还进行了一项随机临床试验，以测试环境干预在降低北卡罗来纳州市中心家庭蟑螂过敏原水平方面的可行性/有效性。我们的研究表明，灭蟑和密集清洁相结合，可以显著降低高感染家庭中的蟑螂过敏原水平。此外，在持续灭杀的情况下，效果可维持长达12个月。令人惊讶的是，在6个月的时间里，仅消灭蟑螂就能显著降低低收入家庭的蟑螂过敏原水平。这些研究的结果将用于设计一项预防试验，以确定旨在降低室内过敏原水平的环境干预是否可以预防致敏，并降低生活在贫困中的高危儿童哮喘的患病率和发病率。

Our asthma research program involves both exposure assessment and prevention components, and focuses on the relationship between exposure to common indoor allergens and asthma prevalence/morbidity. The National Allergen Survey, a study of allergen types and levels in floor and bedding dust in the nation's housing, is the first study to provide estimates of allergen exposure in the U.S. population. It encompasses 831 homes in 75 primary sampling units located throughout the country. The major endpoints are measurements of dust mite, cockroach, cat, dog, mouse, rat and fungal allergen levels, and endotoxin in dust samples collected from an array of sites in the surveyed homes. Results from analysis of dust mite allergens suggest that approximately 24% of U.S. homes have beds that contain >10 microgram dust mite allergen/gram dust (a level previously associated with symptomatic asthma) and approximately 46% of U.S. homes have beds that contain >2 microgram dust mite allergen/gram dust (a level previously associated with mite allergen sensitization). The likelihood of having a high dust mite allergen level in the bed was greater for older homes, non-western region homes, lower income households and bedrooms with higher humidity. Dog and cat allergens were universally present in U.S. homes. Levels were higher among homes with an indoor dog and/or cat; however, among homes without an indoor pet, mean allergen concentrations were still well above proposed thresholds for allergic sensitization and disease. Mouse allergen was detectable in approximately 82% of U.S. homes and levels exceeded proposed sentization thresholds in 22% of homes. The likelihood of having high mouse allergen levels in the kitchen was greater in high rise apartments, mobile homes, older homes, low income homes, homes where rodent or cockroach problems were reported, and when floor mopping was performed instead of vacuuming. This nationally representative survey has (a) provided current estimates of indoor allergen exposure in the U.S. population, (b) established a database that can be used to stimulate future studies which attempt to correlate allergen exposure to disease outcome, (c) provided a baseline that can be used as a reference point for future allergen surveys, and (d) facilitated evaluation of regional, ethnic, socioeconomic, and housing characteristic differences in the allergen burden. We have also conducted a randomized clinical trial to test the feasibility/effectiveness of environmental interventions in reducing cockroach allergen levels in inner-city North Carolina homes. Our study demonstrated that the combination of cockroach extermination and intensive cleaning can significantly reduce cockroach allergen levels in highly infested homes. Moreover, the effect can be maintained for up to 12 months with continued extermination. Surprisingly, cockroach extermination alone can also significantly reduce cockroach allergen levels in low income homes over a 6 month period. The results of these studies will be used to design a prevention trial to determine if environmental intervention aimed at reducing indoor allergen levels can prevent sensitization and decrease the prevalence and morbidity of asthma in high risk children living in poverty.