Occurrence Of Schistosoma Mansoni And Its Transmission Risks In School Children In Schistosome Non-Endemic Kagio Area In Kirinyaga County, Kenya

ABSTRACT

Schistosomiasis is a chronic parasitic disease caused by a blood fluke of the genus Schistosoma. An estimated 249 million people are infected worldwide in about 78 countries with 85% infections occurring in sub-Saharan Africa. In Kenya, an estimated 5 million people are infected with about 12 million people at risk of infection. Schistosomiasis is a major public health concern due to the morbidities caused. Kagio area borders Mwea irrigation scheme which is an endemic area with a prevalence of 47%. The close proximity of Kagio area to the irrigation scheme offers labour opportunities to the population including school children who seek menial jobs and this poses a threat of transmission of schistosomiasis which is common in the irrigation scheme. The study sort to establish the occurrence of schistosomiasis in school children of ages 8-15 years in the non-endemic Kagio area and the endemic Mwea irrigation scheme and compare the levels of the disease in the two areas. Two schools in Kagio area; Kagio primary and Kang’aru primary schools which are at close proximity to the irrigation scheme and one school, Kandongu primary in the irrigation scheme where the pupils from non-endemic area of Kagio go to work were sampled. The pupils provided early morning stool collected in Elkay specimen cups that were checked for schistosome eggs and other helminthes. Macroscopically, stool was checked for presence of mucus or blood, nature and colour. Microscopically, direct saline and iodine wet mounts were done. Eggs were counted systematically from all fields of the slide and tabulated. On the same stool samples, Kato katz was done and eggs present counted in order to check the intensity of infection. Eggs counted were multiplied by 24 to convert the counts to eggs per gram (epg). The eggs present were then classified as light (1-100 epg), moderate (101-400 epg) or heavy (>400 epg) as an indicator of the intensity of infection. Questionnaires were administered to the participating pupils to collect data on their interaction with the endemic Mwea irrigation scheme. The data collected was analyzed using chi-square statistics at 95% confidence level to establish the relationship between occurrence of shistosomiasis in the non-endemic Kagio area and labour migration to the endemic Mwea irrigation scheme and t-test statistics was done to check the difference in occurrence of schistosomiasis in non-endemic area compared to the endemic area and Pearson correlation was done to check for the relationship between visiting in the irrigation scheme and occurrence of schistosomiasis. From microscopic examination of the stool samples, 7.2% of pupils from non-endemic area of Kagio had Schistosoma mansoni eggs in the stool while 22% of pupils sampled from Mwea irrigation scheme had Schistosoma mansoni eggs in their stool. The mean number of eggs for the pupils who had light infection was 56 epg and 104 epg for those who had moderate infection. There were no pupils with heavy infestation. Pupils who worked in the farms were more prone to infection than those who did not with 7.9% of those who had the infection working in the rice paddies compared to 4% of infected pupils who did not. Analysis of results indicated that there was a significant relationship between labour migration and occurrence of Schistosoma mansoni infection among school children in Kagio area (χ2=0.2604; df = 1; P = 0.01). There was no significant difference in infection rates between Kagio and Mwea areas (t=5.33, cl=95%, df=1, P=0.118). The findings from this study conclude that Schistosoma mansoni was present in both endemic and non-endemic areas and that labour migration is a transmission risk. It is recommended that the policy makers institute programmes that are designed to eliminate or minimize child labour migration from non-endemic to endemic areas as a way of preventing spread of schistosomiasis.