Trends in the prevalence and intensity of soil-transmitted helminth (STH) infection in Ethiopia 2000 to 2023: a systematic review

Background

Soil-transmitted helminths (STH) are a source of parasitic infections common in Ethiopia and cause stunting of growth and neurodevelopment. The aim of this review was to examine the trends in STH prevalence and intensity in Ethiopia by year, age group, and region over a period of more than two decades.

Methods

A comprehensive literature review using predefined terms was conducted in PubMed, Scopus, and Web of Science. The relevant studies were screened and reviewed, and the data were extracted and recorded in an Excel spreadsheet. A random-effects model was employed to determine the pooled prevalence. Prevalence estimates and their standard errors were extracted for each period, and pairwise comparisons of estimates between consecutive periods were performed, with P-values computed to assess the statistical significance in the changes recorded.

Results

A total of 310 studies published from 2000 to 2023, focused on STHs in Ethiopia, were included in the analysis. Of these, 298 focused on Ascaris lumbricoides, 250 on Trichuris trichiura, and 278 on hookworms. The majority of studies were conducted in the Amhara region (43.5%), followed by Oromia (26.1%). The overall prevalence of A. lumbricoides decreased from 13.8% (95% confidence interval [CI] 11.5%, 16.8%) before 2015 to 9.4% (95% CI 6.8%, 13.1%) after 2020, with a notable change observed between 2015 and 2019. In contrast, the prevalence of T. trichiura and hookworms did not show a significant change.

Conclusions

Progress has been made in reducing the prevalence and intensity of A. lumbricoides, but there is still some way to go, which will require higher mass drug administration (MDA) coverage levels plus treatment of the whole community including adults, alongside water, sanitation, and hygiene (WaSH) interventions to prevent persistent reinfection. Graphical Abstract