<p>Predictors of Total Number of Infections.</p>

Background

Worldwide, 451 million people and up to 156 million children are infected with hookworm, causing an estimated 3.2 million disability-adjusted life-years annually. We conducted a two-year longitudinal cohort study of hookworm infection with a random selection of 274 school-age children (4–16 yrs) in rural Ghana to identify nutritional and environmental exposures impacting hookworm infection and response to treatment.

Methods

Every six months (baseline Jan 2013) we collected anthropometric measurements, pre- and post-treatment fecal samples, and blood samples. Household surveys and multiple-pass twenty-four-hour recalls were conducted at baseline and 18 months.

Results

Seventy-eight participants (28.5%) were absent from at least 1 time point. Of the 196 that were screened at all five time points, 87 (44.4%) were hookworm-infected>1 time. Assessment of albendazole treatment response was conducted on 83 participants. Sixty (72.3%) were cleared of hookworm infections while 23 (27.5%) remained infected post-treatment (ERR: 0–99%). Treatment efficacy was more likely among children aged over 9.66 years (HR: 1.55; 95% CI: 1.18, 2.04) and those from food-insecure households (HR: 2.26; 95% CI: 1.06, 4.81). Hookworm infection status and albendazole treatment outcome at baseline and 18 months were the dominant influences on infections at 6 and 24 months, respectively. Future risk of infection at both 6 and 24 months had significant environmental and nutritional predictors, although the variables differed.

Conclusions

Global school-based deworming has been associated with reduced rates of hookworm infection among schoolchildren in Africa; however, additional strategies will be necessary for long-term, sustainable control. This study reports on an innovative two-year longitudinal study of school age children with repeated cycles of testing and treatment. We modelled hookworm infection as a function of predictors that were measured six months prior, thereby strengthening the assessment of causal relationships between environmental, infection and nutritional risk factors.