Date of Award

January 2014

Document Type

Open Access Thesis

Degree Name

Master of Public Health (MPH)

Department

School of Public Health

First Advisor

Michael Cappello

Second Advisor

Kaveh Khoshnood

Abstract

One billion people are currently infected with at least one soil-transmitted nematode (STN), and over 161,600 school-aged children in sub-Saharan Africa live in areas where the prevalence exceeds 20%. STN infections cause malnutrition and cognitive deficits that limit productivity and may contribute to endemic poverty. Despite this significant and recognized disease burden, research on these diseases remains piecemeal; the majority of scientific understanding of these conditions is derived from a handful of small studies. Data regarding prevalence, intensity, and effectiveness of treatment of STN infections in Rakai District, Uganda is particularly limited, and the Ministry of Health has discontinued surveillance in the area due to financial constraints. A cross-sectional study of 269 school-aged children was conducted in Rakai District to address this knowledge gap. Fecal samples were collected by household and analyzed using light microscopy. Demographic and behavioral risk factors for infection were assessed via questionnaire. Subjects who were infected with any of the three major soil-transmitted nematodes (hookworm, Ascaris lumbricoides, Trichuris trichiura) were offered treatment with single dose oral albendazole (400 mg). The prevalence of hookworm, Ascaris, and Trichuris, was 55.0%, 49.4%, and 21.2%, respectively, with 70.6% of all subjects infected with at least one STN. In a univariate analysis, young age was associated with hookworm (p = 0.0239), Ascaris (p = 0.0186), and any STN (p = 0.0010) infection. Having a recent history of malaria was a risk factor for hookworm (p = 0.0308), Ascaris (p = 0.0301), and any STN (p = 0.0251). Moderate/heavy infection intensity was associated with increasing poly-parasitism (OR = 5.2) and treatment failure (OR = 2.3). In a multivariate analysis, recent history of malaria and low weight/height were significant predictors of hookworm (adjusted OR: 1.86, 0.95) or Ascaris (adjusted OR: 1.93, 0.94) infections. Pig ownership was a strong predictor of Trichuris infection (adjusted OR: 3.38). The cure rate/egg reduction rates following albendazole treatment were as follows: hookworm: 58/79%; A. lumbricoides: 74/92%; T. trichiura: 82/98 %. In conclusion, this study confirms a high prevalence of three major STN infections in Rakai District, as well as an association with malaria and poor nutritional status. Single dose albendazole therapy exhibited reduced effectiveness, especially against hookworm, in this polyparasitized population. We recommend that future deworming programs in Rakai integrate efforts to modify behavioral risk factors, along with monitoring for treatment effectiveness and emerging anthelminthic resistance.

Comments

This is an Open Access Thesis.

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