The impact of community based interventions for the prevention and control of soil-transmitted helminths: A systematic review and meta-analysis

Soil-transmitted helminths (STHs) are among the most common human infections worldwide and a major cause of morbidity. They are caused by different species of parasitic worms and transmitted by eggs released in faeces or when hookworm larvae penetrate the skin. The main control strategy in endemic regions is periodic treatment with deworming medication. In the last 10 years, there has been a scale-up of prevention and control activities with a focus on community-based interventions (CBIs). This review aims to systematically analyse the impact of CBIs on the prevalence and infection intensity of STHs. A systematic review was published on this topic in 2014, but there have subsequently been several new studies published which are included in this review. Electronic database search of MEDLINE (Ovid), Global Health Online (Ovid), Cochrane Library, Embase (Ovid) and Web of Science was conducted. Titles, abstracts, and full texts were screened by two independent reviewers according to predefined eligibility criteria. Data were extracted and a meta-analysis of included studies was conducted. A total of 11,954 de-duplicated titles were screened, and 33 studies were included in the review. 14 focussed on community-wide treatment, 11 studies investigated school-based interventions, and 3 studies investigating both. Results suggest that CBIs are effective in reducing the prevalence of Hookworm, Trichuris trichiura and Ascaris lumbricoides. School-based treatment and community-wide treatment, as well as annual and semi-annual deworming, all reduce STH prevalence significantly. Mass drug administration was effective in reducing the infection intensity of Hookworm (Mean difference: -211.36 [95% CI: -519.12, 96.39]), Trichuris trichiura (-736.69 [-1349.97, -123.42]) and Ascaris lumbricoides (-2723.34 [-5014.85, -431.84]). The results suggest that CBIs are effective in reducing the prevalence and intensity of STH infections. While most studies delivered preventive chemotherapy (PC), few studies explored the impact of interventions such as water, sanitation, and hygiene (WASH) or health education, which may be essential in preventing reinfection after PC.