Deworming women of reproductive age during adolescence and pregnancy: what is the impact on morbidity from soil-transmitted helminths infection?

Carolin Vegvari,Veronica Malizia,Luc E Coffeng,James E Truscott,Federica Giardina,Robert J Hardwick,Sake J De Vlas,Roy M Anderson,Antonio Montresor,Sumali Bajaj

doi:10.1186/s13071-021-04620-w

Abstract

BackgroundSoil-transmitted helminths (STHs) are a major cause of poor health in low- and middle-income countries. In particular, hookworm is known to cause anaemia in children and women of reproductive age (WRA). One goal of the World Health Organization’s (WHO) 2030 roadmap for neglected tropical diseases is to reduce STH-related morbidity in WRA. As a minimal intervention, the WHO recommends deworming adolescent girls annually during human papilloma virus vaccination programmes and WRA during pregnancy and lactation. These routine interventions are low cost and can be implemented even by the most basic health services in endemic countries. In this study we use a cohort model to investigate the potential impact on STH-related morbidity in WRA.ResultsAnnual deworming treatment of adolescent girls reduces the prevalence of moderate- and heavy-intensity infections in this age group by up to 60% in moderate transmission settings and by 12–27% in high transmission settings. Treatment of WRA during pregnancy and lactation on its own has a small (< 20%) but significant effect on morbidity although it does not lead to the achievement of the morbidity target (< 2% moderate- to high-intensity infections) in this age group. However, depending on the age-intensity profile of infection, which may vary geographically, and assumptions on the density-dependence of egg production by fertilised female worms, continued school-based treatment may be able to reduce the force of infection acting on WRA, both through an indirect effect on the overall population-based force of infection and via reducing the burden of infection as children age and move into the WRA age classes. As a result, morbidity in WRA may be eliminated.ConclusionWhile deworming during pregnancy and lactation does not lead to the achievement of the morbidity target in WRA and its efficacy may vary by setting, it is still expected to be beneficial for maternity and child health. Monitoring of any WRA-based intervention is recommended to evaluate its effectiveness.Graphical

Highlights

Soil-transmitted helminths (STHs) are a major cause of poor health in low- and middle-income countries
The Imperial College London (ICL) model predicts a reduction of 77.8% (95% credible interval [CI] 59.2–91.9%) in the average point prevalence of moderate- and high-intensity (M&HI) infections in women aged 15–50 years where annual SB treatment is ongoing (Fig. 1; Table 2)
For women aged 20–50 years, the Erasmus MC (EMC) model predicts a relative reduction by treatment during pregnancy or lactation in the average point prevalence of M&HI infections of 18.3% where annual SB treatment is implemented and of 19.0% where semi-annual SB treatment is implemented (Figs. 1, 2; Tables 2, 3)

Summary

Introduction

Soil-transmitted helminths (STHs) are a major cause of poor health in low- and middle-income countries. Hookworm is known to cause anaemia in children and women of reproductive age (WRA). The WHO recommends deworming adolescent girls annually during human papilloma virus vaccination programmes and WRA during pregnancy and lactation. These routine interventions are low cost and can be implemented even by the most basic health services in endemic countries. As part of the new 2030 roadmap to achieve morbidity control of STH, the World Health Organization (WHO) recommends the treatment of WRA and adolescent girls (15–19 years) with one dose of 400 mg albendazole [5]. Community-wide treatment of WRA is not economically feasible for most low- and middle-income countries (LMICs) with the presently available resources

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