Diagnosis, Clinical Features, and Self-Reported Morbidity of Strongyloides stercoralis and Hookworm Infection in a Co-Endemic Setting

Abstract

Infections with Strongyloides stercoralis and other helminths represent important, yet often neglected issues in developing countries. Indeed, strongyloidiasis can be fatal, but only a few studies provide information regarding its health relevance in Africa. Moreover, clinical data on symptomatology and typical recognition patterns mainly originate from Western travel clinics. A cross-sectional epidemiological survey was carried out in a rural part of south-central Côte d'Ivoire. Stool samples from 292 randomly selected individuals were examined for intestinal helminths, using a suite of diagnostic techniques (i.e., Kato-Katz, Baermann funnel, and Koga agar plate). Participants were interviewed with a pre-tested questionnaire and clinically examined. Multivariate logistic regression analysis was done to relate perceived morbidity and clinical findings to helminth infection status. The prevalence of hookworm and S. stercoralis was 51.0% and 12.7%, respectively. Both infections were strongly associated with each other (adjusted odds ratio, 6.73; PS. stercoralis-infected individuals expressed self-reported morbidity considerably more often than those with hookworm infection. Clinical examination identified high prevalences of various pathologies and detected tendencies to worse health conditions in helminth-infected subjects. The use of multiple diagnostic tools showed that S. stercoralis and hookworm are co-endemic in rural Côte d'Ivoire and that each infection causes clinical symptoms and sequelae. Our findings are important for (re-)estimating the burden of helminth infections, and highlight the need for integrating epidemiological surveys, rigorous diagnostic approaches, and clinical assessments in the developing world. Infections with parasitic worms such as hookworm and threadworm (Strongyloides stercoralis) are widespread throughout the developing world. However, the symptoms caused by parasitic worms are unspecific and little is known about clinical presentations in endemic countries, and hence doctors' awareness of these diseases is usually low. Many infections therefore remain undetected and untreated over long time periods. As a consequence, parasitic worms can impair the well-being of infected individuals and cause harmful, sometimes even fatal health outcomes. To improve the knowledge about clinical signs and symptoms caused by parasitic worms, we administered a questionnaire to 292 children and adults in rural Côte d'Ivoire, examined them clinically, and looked at their stool for parasitic worm infections. We found that people with parasitic worms reported some symptoms, especially disorders of the gastrointestinal tract, more often than those without worms. Our clinical examination showed a trend toward worse health conditions in worm-infected people, particularly in those with S. stercoralis. Our results are important to improve patient management and control measures, and to better estimate the true health impact of parasitic worm infections.