Background: Soil-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. Results: Annual 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. Conclusion: While 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.[Figure not available: see fulltext.]
Bibliographical noteFunding Information:
The work was funded by the Bill and Melinda Gates Foundation (INV-01010) in partnership with the Task Force for Global Health through the NTD Modelling Consortium [OPP105116 and OPP108566]. CV, SB, RJH, JET, RMA are supported by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement which is also part of the EDCTP2 programme supported by the European Union. JET, RJH, RMA were supported by the Bill and Melinda Gates Foundation via the DeWorm3 (OPP1129535) award to the Natural History Museum in London. LEC further acknowledges funding from the Dutch Society for Scientific Research [NWO, grant 016.Veni.178.023]. FG acknowledges funding from a European Marie Skłodowska-Curie fellowship (H2020-COFUND-2015-FP-707404). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
© 2021, The Author(s).