Strongyloides stercoralis infection in Ethiopia: systematic review and meta-analysis on prevalence and diagnostic methods

Summary Strongyloides stercoralis is a helminthic intestinal parasite that causes the disease strongyloidiasis. Its prevalence is high in tropics and sub-tropics due to poor sanitation and hygiene. However, its true prevalence is not well known in Ethiopia as most health institutions use low sensitive diagnostic methods. This review aimed to determine the pooled prevalence of S. stercoralis at country, and regional state levels. Papers published on S. stercoralis in Ethiopia from 2010 to 2020 were collected from PubMed, Google Scholar and Science direct databases and Addis Ababa repository. Identification, screening, checking the eligibility, and inclusion of the relevant literatures were done. Articles with S. stercoralis positive results from Ethiopian populations were included. Articles which focused on Strongyloides infection in foreigners, and other than stool samples were excluded. The pooled prevalence of S. stercoralis and heterogeneity between studies and across regions were computed. From the 43 articles, the overall prevalence of S. stercoralis in Ethiopia was 1.82 %. Across regions, relatively high prevalence of S. stercoralis (8.78 %) was recorded in Addis Ababa city. High prevalence of S. stercoralis was found to be 44.02 % with a combination of formol ether concentration, Baermann concentration, and molecular methods. Low prevalence of 0.26 %, 0.31 %, and 1.20 % was evidenced respectively with Kato-Katz, direct saline microscopy, and formol ether concentration methods. Using random effect analysis, the pooled prevalence of S. stercoralis in Ethiopia, across regions and across diagnostic methods was 2.1 % (95 %CI: 1.20 – 3.60), 2.6 % (95 %CI: 0.80 – 8.20) and 3.7 % (95 %CI: 1.10 – 11.70), respectively. The heterogeneity was high (P<0.001). This review revealed that Strongyloides infection is probably underreported and its prevalence could be higher than the reported in Ethiopia. Therefore, a revision of the best combination of diagnostic methods could be advisable as it gives better diagnostic results in routine diagnosis of Strongyloides infection in Ethiopia.