Effects of treating helminths during pregnancy and early childhood on risk of allergy‐related outcomes: Follow‐up of a randomized controlled trial

Abstract

BackgroundHelminth infections, common in low‐income countries, may protect against allergy‐related disease. Early exposure may be a key. In the Entebbe Mother and Baby Study, treating helminths during pregnancy resulted in increased eczema rates in early childhood. We followed the cohort to determine whether this translated to increased asthma rates at school age.MethodsThis randomized, double‐blind, placebo‐controlled trial, conducted in Entebbe, Uganda, had three interventions. During pregnancy, women were randomized, simultaneously, to albendazole vs placebo and to praziquantel vs placebo. Their children were independently randomized to quarterly albendazole vs placebo from age 15 months to 5 years. We here report follow‐up to age 9 years. Primary outcomes at 9 years were recent reported wheeze, skin prick test positivity (SPT) to common allergens and allergen‐specific IgE positivity to dust mite or cockroach. Secondary outcomes were doctor‐diagnosed asthma and eczema rates between 5 and 9 years, recent eczema, rhinitis and urticaria at 9 years, and SPT and IgE responses to individual allergens.Results2507 pregnant women were enrolled; 1215 children were seen at age nine, of whom 1188 are included in this analysis. Reported wheeze was rare at 9 years (3.7%) while SPT positivity (25.0%) and IgE positivity (44.1%) were common. There was no evidence of a treatment effect for any of the three interventions on any of the primary outcomes.ConclusionsPrenatal and early‐life treatment of helminths, in the absence of change in other exposures, is unlikely to increase the risk of atopic diseases later in childhood in this tropical, low‐income setting.

The environment and its effect on allergic sensitization and atopic dermatitis, and colostrum and the immune system of the preterm infant

“…3 Such an environment is definitely of interest, as has been shown earlier in PAI that the presence of parasites might influence allergies. 4,5 As expected and shown earlier in birth cohorts from high-income countries in the Western Hemisphere, sensitization increases gradually during the first years of life. 6,7 The authors further explored sensitization in relation to hygienic conditions (toilets in the housing unit, connection to sewage…) and did find a significantly lower odds ratio in relation to better conditions.…”

“…In the first of my highlighted articles, Zakzuk and colleagues have investigated the pattern of sensitization to Blomia tropicalis, a common tropical mite, as well as to Ascaris in a population of children living in a low‐income neighborhood in Cartagena, Colombia . Such an environment is definitely of interest, as has been shown earlier in PAI that the presence of parasites might influence allergies . As expected and shown earlier in birth cohorts from high‐income countries in the Western Hemisphere, sensitization increases gradually during the first years of life .…”

Parasites and allergy: Observations from Africa

“…Albendazole treatment in early childhood was not associated with allergy‐related outcomes . However, the effects of anthelmintic treatment in pregnancy on clinical asthma could not be measured due to the small number of children who developed asthma in this cohort . This birth cohort also showed that the children's own helminth infections in early life (hookworm and Trichuris ) were associated with a reduced risk of eczema in later childhood .…”

Editor's Choice

“…In a semi‐urban setting in Uganda, the authors of this study found previously that treatment of helminths during pregnancy resulted in increased rates of infantile eczema. Therefore, they followed the trial cohort to determine whether such treatment in pregnancy, and in early life, would go on to increase the risk of asthma and other ARDs later in childhood.…”