Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, L3 5QA, UK.
BMC Infect Dis. 2011 Jun 29;11:184. doi: 10.1186/1471-2334-11-184.
Geohelminth infections are highly prevalent infectious diseases of childhood in many regions of the Tropics, and are associated with significant morbidity especially among pre-school and school-age children. There is growing concern that geohelminth infections, particularly exposures occurring during early life in utero through maternal infections or during infancy, may affect vaccine immunogenicity in populations among whom these infections are endemic. Further, the low prevalence of allergic disease in the rural Tropics has been attributed to the immune modulatory effects of these infections and there is concern that widespread use of anthelmintic treatment in high-risk groups may be associated with an increase in the prevalence of allergic diseases. Because the most widely used vaccines are administered during the first year of life and the antecedents of allergic disease are considered to occur in early childhood, the present study has been designed to investigate the impact of early exposures to geohelminths on the development of protective immunity to vaccines, allergic sensitization, and allergic disease.
METHODS/DESIGN: A cohort of 2,403 neonates followed up to 8 years of age. Primary exposures are infections with geohelminth parasites during the last trimester of pregnancy and the first 2 years of life. Primary study outcomes are the development of protective immunity to common childhood vaccines (i.e. rotavirus, Haemophilus influenzae type B, Hepatitis B, tetanus toxoid, and oral poliovirus type 3) during the first 5 years of life, the development of eczema by 3 years of age, the development of allergen skin test reactivity at 5 years of age, and the development of asthma at 5 and 8 years of age. Potential immunological mechanisms by which geohelminth infections may affect the study outcomes will be investigated also.
The study will provide information on the potential effects of early exposures to geohelminths (during pregnancy and the first 2 years of life) on the development of vaccine immunity and allergy. The data will inform an ongoing debate of potential effects of geohelminths on child health and will contribute to policy decisions on new interventions designed to improve vaccine immunogenicity and protect against the development of allergic diseases.
Current Controlled Trials ISRCTN41239086.
在许多热带地区，土源性寄生虫感染是儿童中高度流行的传染病，与发病率显著相关，尤其是在学龄前和学龄儿童中。越来越多的人担心，土源性寄生虫感染，特别是在子宫内通过母体感染或在婴儿期发生的早期生活暴露，可能会影响这些感染流行地区人群的疫苗免疫原性。此外，热带农村地区过敏疾病的低患病率归因于这些感染的免疫调节作用，人们担心在高危人群中广泛使用驱虫治疗可能与过敏疾病的患病率增加有关。由于最广泛使用的疫苗是在生命的第一年接种的，而过敏疾病的前兆被认为发生在儿童早期，因此本研究旨在调查早期接触土源性寄生虫对疫苗保护性免疫、过敏致敏和过敏疾病发展的影响。
方法/设计：对 2403 名新生儿进行了队列研究，随访至 8 岁。主要暴露是在妊娠最后三个月和生命的前 2 年内感染土源性寄生虫。主要研究结果是在生命的前 5 年内发展出对常见儿童疫苗（即轮状病毒、流感嗜血杆菌 b 型、乙型肝炎、破伤风类毒素和口服脊髓灰质炎病毒 3 型）的保护性免疫、3 岁时出现湿疹、5 岁时出现过敏原皮肤试验反应以及 5 岁和 8 岁时出现哮喘。还将研究土源性寄生虫感染可能影响研究结果的潜在免疫机制。
该研究将提供有关早期接触土源性寄生虫（在妊娠和生命的前 2 年内）对疫苗免疫和过敏发展的潜在影响的信息。这些数据将为土源性寄生虫对儿童健康的潜在影响的持续争论提供信息，并为旨在提高疫苗免疫原性和预防过敏疾病发展的新干预措施的决策提供依据。
当前对照试验 ISRCTN41239086。
