Intestinal Parasitic Infections among Prison Inmates and Tobacco Farm Workers in Shewa Robit, North-Central Ethiopia

BACKGROUND: Intestinal parasitic infections (IPIs) particularly soil-transmitted helminthiasis (STH) and schistosomiasis are among neglected tropical diseases (NTDs) globally. Apart from being associated with anemia, malabsorption and retarded cognitive development these diseases are complicating the clinical picture of more serious infections like HIV, TB and malaria. Renewed and up-to-date information on the epidemiology of IPIs in more vulnerable groups such as irrigated-farm workers and prisoners would significantly contribute towards improving the health condition of such at-risk groups. METHODS: A cross-sectional survey was conducted to determine the prevalence of IPIs among prison inmates and tobacco farm workers in Shewa-Robit, north-central Ethiopia in November 2008. A total of 236 fecal samples were examined microscopically to detect helminths and/or protozoa using direct-smear and formol-ether concentration methods. RESULTS: Overall, 8 intestinal parasite species have been recovered singly or in combinations from 146 (61.8 %) samples. The prevalence in prison population (88/121 = 72.7%) was significantly higher than that in tobacco farm (58/115 = 50.4%). There were no significant differences in the prevalence of IPI by most socio-demographics. Except for hookworm there was no significant difference in parasite prevalence between different age-groups though the frequency of individual parasites slightly varied between the age-groups. Multivariate logistic regression analysis showed that inmates were more likely to acquire IPIs than tobacco-farm workers (Odds Ratio (OR) = 2.62, 95% confidence interval (CI) = 1.52–4.5). In addition, participants who did not report past treatment for IPIs were more likely to acquire IPIs than participants who self-reported treatment for IPIs in the past twelve months (OR = 3.25, 95% CI = 1.75–6.06). All other socio-demographics were not significantly associated with IPIs in univariate analysis. Entamoeba histolytica/dispar/moshkovskii was the most frequently encountered species in both study sites accounting for 48.8 and 51.7 percent of the positives in prison and tobacco farm population respectively. Other intestinal parasites detected, with slight variation in prevalence in the two study areas, were hookworm, Ascaris lumbricoides, Trichuris trichiura, Schistosoma mansoni, Strongyloides stercolaris, Hymenolepis nana and Taenia sp. 35.5 and 33.0 percent of the total positive cases were mixed infections in Shewa Robit prison and tobacco farm, respectively. CONCLUSION: The results show that IPIs are common health problems in the studied populations.