Impact of early life geohelminths on wheeze, asthma and atopy in Ecuadorian children at 8 years

Abstract

Background Early‐life exposures to geohelminths may protect against development of wheeze/asthma and atopy. Objective To study the effect of maternal geohelminths and infections in children during the first 5 years on atopy, wheeze/asthma and airways reactivity/inflammation at 8 years. Methods Birth cohort of 2404 neonates followed to 8 years in rural Ecuador. Data on wheeze/asthma were collected by questionnaire and atopy by skin prick test (SPT) reactivity to 9 allergens. We measured airways reactivity to bronchodilator, fractional exhaled nitric oxide (FeNO) and nasal eosinophilia. Stool samples were examined for geohelminths by microscopy. Results 1933 (80.4%) children were evaluated at 8 years. Geohelminths were detected in 45.8% of mothers and 45.5% of children to 5 years. Frequencies of outcomes at 8 years were as follows: wheeze (6.6%), asthma between 5 and 8 years (7.9%), SPT (14.7%), airways reactivity (10%) and elevated FeNO (10.3%) and nasal eosinophilia (9.2%). Any maternal geohelminth was associated with reduced SPT prevalence (OR 0.72). Childhood Trichuris trichiura infections during the first 5 years were associated with reduced wheeze (OR 0.57) but greater parasite burdens with Ascaris lumbricoides at 5 years were associated with increased wheeze (OR 2.83) and asthma (OR 2.60). Associations between maternal geohelminths and wheeze/asthma were modified by atopy. Parasite‐specific effects on wheeze/asthma and airways reactivity and inflammation were observed in non‐atopic children. Conclusions Our data provide novel evidence for persistent effects of in utero geohelminth exposures on childhood atopy but highlight the complex nature of the relationship between geohelminths and the airways. Registered as an observational study (ISRCTN41239086).

Patterns of Allergic Sensitization and Factors Associated With Emergence of Sensitization in the Rural Tropics Early in the Life Course: Findings of an Ecuadorian Birth Cohort

“…an analysis that ignored the effects of age on the acquisition of SPT+) in which protective effects were observed among children of STH-infected mothers. In the previous analysis, strongest protective effects against SPT+ at 8 years were seen among children with STH infections during the first 5 years of life who also had infected mothers ( 11 ). Here, using an analysis that estimated age-dependent risk of SPT+ rather than at a single point in time, we observed a significant protective effect of maternal infections with T .…”

“…Maternal questionnaires were repeated at the time points listed above. Presence of allergic disease symptoms at 8 years of age were defined as described ( 11 , 14 ).…”

“…We have shown previously in a birth cohort, from a tropical rural district of coastal Ecuador, followed to 8 years of age, that childhood and or maternal STH parasites protected against the development of mite sensitization at 3 years ( 9 ), to perennial allergens at 5 years of age ( 10 ), and to any allergen when measured at 8 years of age ( 11 ). In the present analysis, we describe the development and patterns of allergic sensitization measured by allergen SPT+ to school age and explore the potential role of a range of relevant ante-natal and post-natal individual and environmental risk factors, with a particular focus on the role of exposures associated with poor hygiene, in determining the emergence early in the life course of SPT+ in this tropical setting.…”

Yaws elimination in Ecuador: Findings of a serological survey of children in Esmeraldas province to evaluate interruption of transmission

“…The protocols of each of the three surveys used for the present analysis were approved by local ethics committees in Ecuador as described [ 10 , 12 , 13 ]. The protocol for this retrospective analysis of stored samples was approved by the Ethics Committee of the Universidad Central del Ecuador (Reference 001-SEISH-UCE-20).…”

“…Samples were collected between 2005 and 2017 as part of two observational studies of allergy in children in the Districts of Eloy Alfaro, San Lorenzo, and Quininde in Esmeraldas Province: the first study was a cross-sectional survey of school age children aged 6 to 15 years (predominantly of Afro-Ecuadorian ethnicity in the Districts of Eloy Alfaro and San Lorenzo including formerly endemic and non-endemic communities) using updated censuses of each community with blood sampling between 2005 and 2009 [ 10 ] while the second was a population-based birth cohort (predominantly of mestizo ethnicity in the District of Quininde in geographically close but non-endemic communities) in which serum samples collected between 2014 and 2017 were analysed at 8 to 9 years [ 11 , 12 ]. Sera from a survey of indigenous Awa children aged 2 to 15 years in the District of San Lorenzo (of unknown endemicity for yaws) collected in 2014 and 2015 were analyzed also [ 13 ].…”