Journal Article

Impact of ivermectin mass drug administration on burden of soil-transmitted helminths in onchocerciasis control and elimination programs, Yeki district, southwest Ethiopia

Gebrezgabiher, Gebremedhin, Hailu, Asrat, Ayana, Mio, Yewhalaw, Delenasaw, Mekonnen, Zeleke

2022

Overview

Community-directed treatment with ivermectin (CDTi) is the primary strategy employed to control and eliminate human onchocerciasis in Ethiopia. After long-term mass distribution for onchocerciasis, ivermectin is expected to have additional benefits beyond the envisioned targets by reducing the burden of other co-endemic parasitic infections as to STHs. To date, studies focused on the collateral impact of CDTi on STH in Ethiopia are scanty. Two community-based cross-sectional surveys (baseline in 1997 and post-CDTi in 2017) were conducted to evaluate the impact of long-term CDTi employed to control and eliminate onchocerciasis on the burden of STH infections in Yeki district of southwest Ethiopia. Stool samples were collected and examined using Ritchie`s concentration and Kato-Katz techniques in the baseline and current study, respectively. Overall, 188(38.3%, 95% Confidence interval (CI) 34.1–42.7%) individuals were positive at least for any of the STH species from 491 study participants in the post-CDTi. The prevalence of A . lumbricoides , hookworms, and T . trichiura was 11.2% (95% CI 8.7–14.3%), 16.3% (95% CI 13.3–19.8%), and 29.9% (95% CI 26.1–34.1%), respectively. Individuals aged 5–9 years had a significantly higher prevalence of A . lumbricoides (Adjusted odds ratio (AOR) 6.5, 95% CI 1.7–25.4), T . trichuria (AOR 8, 95% CI 2.6–25.1), and any STH infection (AOR 5, 95% CI 1.7–14.7) than those of ≥ 51 years. Also, significantly higher prevalences of T . trichuria infection were observed in individuals aged 10–14 years (AOR 4.1, 95% CI 1.7–9.9), 15–20 years (AOR 3.1, 95% CI 1.2–8.1), 21–30 years (AOR 2.4, 95% CI 1.1–5.5), and 31–40 years (AOR 3.2, 95% CI 1.3–7.5) compared with those of ≥ 51 years. The prevalence of A . lumbricoides was significantly higher in males (AOR 0.5, 95% CI 0.3–0.9). Of the 491 study participants, only data from 400 individuals who had not been involved in a mass drug administration (MDA) with other STH anthelmintics were considered in the comparative analysis. Before CDTi, the prevalence of A . lumbricoides , T . trichiura , hookworm, and any STH infection was 47.1% (95% CI 41.6–52.7%), 3.3% (95% CI 1.8–5.9%), 37.9% (95% CI 32.7–43.5%), and 58.8% (95% CI 53.2–64.1%), respectively. Long-term CDTi considerably reduced the prevalences of A . lumbricoides and hookworm by 76.2% and 56.9%, respectively (p < 0.001). Nonetheless, CDTi did not affect the prevalence of T . trichiura infection and, in contrast, it was significantly higher in the current study (P < 0.001). Overall post-CDTi prevalence of any STH infection was considerably lower than reported in the baseline (p < 0.001). It is evidenced that long-term CDTi for onchocerciasis control and elimination had additional benefits by reducing the prevalence of STH infections specifically of A . lumbricoides and hookworm, but had no impact on infections with T . trichuria . Our finding of additional health benefits of large-scale ivermectin administration taking it will aid to increase positive engagement and sustain participation of communities during MDA campaigns, and strengthen governmental and non-governmental organizations (NGOs) support for the undergoing national onchocerciasis elimination program.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adolescent / Adult / Age Factors / Animals / Anthelmintic agents / Antiparasitic agents / Biology and Life Sciences / Child / Community / Community involvement / Community participation / Comparative analysis / Confidence intervals / Control / Cross-Sectional Studies / Drug therapy / Ethiopia - epidemiology / Feces - parasitology / Female / Helminthiasis - classification / Helminthiasis - epidemiology / Helminths / Helminths - classification / Helminths - drug effects / Helminths - isolation & purification / Humans / Infections / Ivermectin / Ivermectin - administration & dosage / Ivermectin - pharmacology / Male / Mass distribution / Mass Drug Administration / Medical laboratories / Medicine and Health Sciences / Middle Aged / Morbidity / NGOs / Nongovernmental organizations / Onchocerciasis / Onchocerciasis - prevention & control / Parasitic diseases / Prevalence / Sex Characteristics / Soil - parasitology / Spatial data / Tropical diseases / Young Adult