Maternal Geohelminth Infections Are Associated with an Increased Susceptibility to Geohelminth Infection in Children: A Case-Control Study

Raaj S Mehta,Nely Broncano,Alejandro Rodriguez,Irene Guadalupe,Fernanda Tupiza,Martha Chico,Philip J Cooper,Carlos Sandoval,Edward Mitre

doi:10.1371/journal.pntd.0001753

Abstract

BackgroundChildren of mothers infected with soil-transmitted helminths (STH) may have an increased susceptibility to STH infection.Methods and FindingsWe did a case-control study nested in a birth cohort in Ecuador. Data from 1,004 children aged 7 months to 3 years were analyzed. Cases were defined as children with Ascaris lumbricoides and/or Trichuris trichiura, controls without. Exposure was defined as maternal infection with A. lumbricoides and/or T. trichiura, detected during the third trimester of pregnancy. The analysis was restricted to households with a documented infection to control for infection risk. Children of mothers with STH infections had a greater risk of infection compared to children of uninfected mothers (adjusted OR 2.61, 95% CI: 1.88–3.63, p<0.001). This effect was particularly strong in children of mothers with both STH infections (adjusted OR: 5.91, 95% CI: 3.55–9.81, p<0.001). Newborns of infected mothers had greater levels of plasma IL-10 than those of uninfected mothers (p = 0.033), and there was evidence that cord blood IL-10 was increased among newborns who became infected later in childhood (p = 0.060).ConclusionOur data suggest that maternal STH infections increase susceptibility to infection during early childhood, an effect that was associated with elevated IL-10 in cord plasma.

Highlights

Soil-transmitted helminths (STHs, known as geohelminths or intestinal helminths) are estimated to infect 2 billion people worldwide [1]
Our data suggest that maternal soil-transmitted helminths (STH) infections increase susceptibility to infection during early childhood, an effect that was associated with elevated IL-10 in cord plasma
We evaluated whether children of mothers infected with STH infections have a greater risk of infection when compared to children of uninfected mothers

Summary

Introduction

Soil-transmitted helminths (STHs, known as geohelminths or intestinal helminths) are estimated to infect 2 billion people worldwide [1] These parasites, of which Ascaris lumbricoides and Trichuris trichiura are the most prevalent, are a major cause of morbidity related to malnutrition and reductions in childhood growth [2]. Heterogeneity in exposure to infective stages may be relevant, but host factors must be involved, as suggested by individuals reacquiring heavy infections after treatment [5]. Understanding these factors is likely to help us develop novel interventions to complement mass drug administration (MDA) with anthelmintic drugs, and make MDA more efficient thereby reducing rates of re-infection. Children of mothers infected with soil-transmitted helminths (STH) may have an increased susceptibility to STH infection

Methods

Results

Conclusion