EPIDEMIOLOGY AND BURDEN OF SCHISTOSOMA HAEMATOBIUM INFECTION AMONG SCHOOL CHILDREN IN OSUN STATE, NIGERIA.

Schistosoma Haematobium Infection Among School Children in Osun State, Nigeria

Abstract

Background: Urinary schistosomiasis is one of the most prevalent Neglected Tropical Diseases (NTDs) and remains a major public health problem among school-aged pupils in tropical and subtropical countries.

Objective: This study assessed the current status of urinary schistosomiasis among school children in a rural community in Southwestern Nigeria.

Materials and Methods: A school-based cross-sectional study was conducted in Ore Community, Odo-Otin Local Government area in Osun state, Nigeria. Urine specimens were collected from 300 school children, and were processed using sedimentation technique and examined microscopically for the ova of Schistosoma haematobium. Infected participants were treated with oral doses of praziquantel (PZQ) at 40 mg/Kg body weight.  The egg reduction rate was used to assess the drug efficacy.  The population abundance of the snail intermediate hosts was assessed using hand-held scooping. Cercaria shedding was assessed and species of snails identified based on shell morphology. Data were analysed with the SPSS version 18.0 software

Results: A prevalence of 73.3% (19.13±29.13) of urinary schistosomiasis was recorded among the study participants. Male students (52.70%, 9.86±18.33) were more infected than females (47.27%, 19.26±29.13).  Prevalence of infection decreases as the age increases with the highest prevalence among the age group 13 to 16 years (66.5%,14.28±26.40) and the lowest among the age group 17 to 21years (62.5%, 7.09±8.13). The 220 Schistosoma haematobium infected children received a single oral dose of 40 mg/kg of PZQ and were followed for 12 weeks.  At 4th, 8th and 12th weeks after treatment, the   ERR   was   65.70%, 82.91%   and   100%, consecutively.   ERR   was significantly higher in children with mild infection compared to those with severe infection. Ninety-nine (90.5%) children were microscopically negative four weeks after treatment. After the second treatment cycle, the cure rate at the 8th and 12th weeks wasv98.60% and 100% sequentially.  Three different freshwater snails were obtained from the study area. The percentage distribution of the three snail hosts population is as follows: Bulinus spp (26.0%), Biomphalaria spp. (12.3%) and Oncomelania spp (61.7%). The highest cercariae shedding snail was the Bulinus spp.

Conclusion: The results revealed a high prevalence of urinary schistosomiasis among school children with associated impacts on the packed cell volume.  The therapeutic potency of PZQ at 40 mg/kg against S. haematobium was re-established.