Intestinal schistosomiasis in an apparently healthy rural population in Bayelsa State, Nigeria

Abstract

Background: Schistosomiasis is endemic in Nigeria and three species; Schistosoma haematobium, Schistosoma mansoni, and Schistosoma intercalatum have been reported in Niger Delta, Nigeria. This study aimed to determine the prevalence of schistosomiasis in rural communities of Bayelsa State, Nigeria.
Methodology: Four rural homogeneous communities; Otuegala, Immiringi, Otuesega, and Ibelebiri in Ogbia Local Government Area of Bayelsa State, Nigeria, were randomly selected for the study. A structured questionnaire was administered to each participant in their native language and used to collect participant’s biodata and swimming history. Stool samples collected from all participants were examined qualitatively by wet preparation and after formolethol concentration. Data were analyzed using SPSS version 20.0 software and results presented in proportion and tables.
Results: A total of 829 participants (age range 1 - 80 years) were recruited for the study. Helminth ova were identified in the stool samples of 218 (26.3%) participants. Among 380 males examined, 82 (21.6%) were infected, while out of 449 females examined, 138 (30.3%) were infected. The ova of seven helminths identified and their frequency of occurrence were; S. intercalatum 86 (10.4%), Ascaris lumbricoides 53 (6.4%), S. mansoni 35 (4.2%), Trichuris trichiura 22 (2.6%), hookworm 20 (2.4%) and Taenia spp 2 (0.2%). Schistosoma haematobium was identified in non-urine contaminated stool sample of an eight-year old boy. A total of 11 (1.3%) participants had double infections, affecting 7 (63.6%) females and 4 (36.4%) males, with the commonest combination being S. intercalatum and A.
lumbricoides 6 (0.7%), followed by S. intercalatum and hookworm 4 (0.5%), and S. mansoni and hookworm 1(0.1%).
Conclusion: S. intercalatum was the most prevalent intestinal helminthic infection in this study, which is a rare finding in most epidemiological investigations. The affinity of Schistosoma species to establish double infections with hookworm and other intestinal helminths should be taken into account during chemoprophylaxis.

Keywords: Schistosomiasis, Chemoprophylaxis, Prevalence, Rural Population