Estimation of Ivermectin Treatment Demand for the Management of Strongyloidiasis Cases Worldwide: A Systematic Review
Author(s): Heron Gezahegn Gebretsadik
Background: Strongyloides stercoralis is an intestinal helminth that infects humans through contact with larval soil. The infection is often asymptomatic and can only be detected by eosinophilia in peripheral blood. Therefore, serology is the most reliable method for diagnosing the infection. The disease is treated with 2 × 200 μg/kg ivermectin administered orally at two-week intervals. However, the need for this medication to treat strongyloidiasis cases worldwide is unknown. All available data were systematically reviewed and summarized to estimate the global need for ivermectin treatment.
Methods: A systematic electronic literature search was performed in the PubMed, WHOLIS, and ISI Web of Science databases for articles published between January 1990 and May 2017. Articles with quantitative data on prevalence, incidence, duration of infection, remission/cure, and mortality in humans were included. After obtaining the raw data from the systematic review, adjustments were made for diagnostic accuracy, reference population selection, and adjustments for age and reference year 2017 as a prerequisite for estimating the total number of strongyloidiasis cases in humans worldwide. The corresponding ivermectin treatment needs were then derived.
Results: One hundred and sixty-six articles were identified as relevant for data analysis. The analysis revealed that an estimated 159 542 655 people were infected with S. stercoralis worldwide in the best-case scenario and 260 710 055 in the worst-case scenario. Accordingly, the corresponding ivermectin treatment requirements were calculated to be 422,043,504 and 1,379,330,000 ivermectin 3-mg tablets for the best-case and worst-case scenarios. The calculation assumed a single tablet per day for 1- and 2-day treatment recommendations.
Conclusions: To begin disease control, approximately 422,043,504 to 1,379,330,000 ivermectin tablets would be required based on the results of this study, not including occasional ivermectin treatment by other programs. This estimate could be important for policymakers and other stakeholders to address the disease worldwide.