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

Abstract

Background

Hookworm is a soil-transmitted nematode (STN) infection associated with rural poverty that infects 576-740 million people worldwide, 200 million of which reside in Sub-Saharan Africa. In 2001, the WHO passed a resolution that recommended annual deworming for school-aged children where the prevalence of STNs is higher than 20%. Since this time, albendazole has been widely used across sub-Saharan Africa to treat hookworm infection. Given the widespread use of albendazole as a treatment for hookworms and other STNs in humans, it becomes pertinent to ensure that resistance is monitored at the local level, and detected as it emerges. Previous research in Kintampo, Ghana found a high prevalence of low intensity hookworm infection prior to treatment, and raised concerns about emerging resistance to albendazole.

Methods

Children between the ages of 7-12 from four villages were enrolled in this study and given a questionnaire to gather demographic and health information about each participant (n=178). Fecal containers were distributed to enrolled children and the Kato-Katz technique was used to identify a positive infection and to estimate the severity of the infection. Children that were infected with hookworm were treated with a single dose of 400mg albendazole, and a second stool sample was collected from these children at 10-14 days post-treatment. Kato-Katz methods, Egg Extraction, EHA, and the Baermann method were conducted on all positive samples pre- and post-treatment. Genomic DNA was extracted from frozen purified hookworm eggs and larvae from pre- and post-treatment samples and stored for future testing. Molecular methods were utilized to identify the hookworm species in each sample.

Results

At baseline, 57/178 (32.0%) of children from four villages were positive for hookworm. The highest prevalence was seen in Jato (43.7%), while the lowest prevalence was observed in Tahiru (8.0%). Post-treatment, 36.8% (21/57) of children infected at baseline were still hookworm positive. All of the children from Cheranda and Tahiru were cleared of infection, while in Mahama, one child harbored a light infection (CR=80%, FECR=97.9%). In Jato the cure rate was low (55.5%) and the Fecal Egg Count Reduction rate (FECR) was suboptimal (87.9%). Pre-treatment, almost all children harbored light infections, while all children were lightly infected post-treatment.

Discussion

These data demonstrate the need for more targeted approaches to the treatment of helminth infections, as variable responses are observed within each community. Findings from Jato suggest that in some communities, therapeutic intervention alone is not enough. Control measures such as health education or providing access to latrines could make a more substantial impact in communities like Jato, where MDA has been implemented, and where infection rates continue to be high among school-aged children. Data from this study further support the need for new approaches to combat the disease burden posed by helminth infections in much of the developing world.

Comments

This is an Open Access Thesis.

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