Infection Rates Of Schistosoma Haematobium Among Primary School Children In Garsen Constituency, Tana River County, Kenya And The Types Of Snail Vectors

ABSTRACT

Schistosomiasis, also known as bilharziases is a parasitic disease caused by blood flukes (trematodes) of the genus Schistosoma. Both urinary schistosomiasis caused by Schistosoma haematobium and intestinal schistosomiasis caused by S. mansoni occur in various regions of Kenya, including the coastal region. River Tana which flows through Garsen, offer breeding sites for Bulinus snails which are the fresh water snail vectors for S. haematobium. Despite the WHO recommending the strategy for control of schistosomiasis by school based mass drug administration with praziquantel every three months in endemic areas, the program has not been rolled out in this area, hence the full extent of the infection in the area was unknown. There was therefore, need to institute studies to explore the extent and intensity of the infection in Garsen area of Tana River County. The objective of this study was to assess the infection rates and intensity of S. haematobium infections among the school going children. The study also determined the main water contact activities influencing infection and also the species of Bulinus snails involved in the transmission of the infection. The target population comprised of primary school going children, aged 8 to 16 years in class 3 to 7, from 5 selected schools in Garsen sub - county. The study was a cross sectional survey which involved collection and examination of urine samples using a microscope for diagnosis as well as quantification of eggs for determination of intensity. Gross examination of urine coloration and reagent strips was used to assess hematuria. Questionnaires were used to collect qualitative data which included occupation of the parents, age of the children and water contact activities. Sampling of snails was done to determine the snail species involved in transmission in the study area. Variations in prevalence of schistosomiasis among age group 8-10, 11-13 and 14-16 were analyzed by ANOVA. T test was used to compare the difference in infection rates and intensities between male and female pupils. Correlation coefficient (r) was used to relate the rate of infection in relation to the proximity to River Tana and irrigated farm. An overall prevalence of 21% was obtained with male pupils recording the highest prevalence of 28%. A total egg count of 3798 eggs per 10 ml of urine was recorded among 63 pupils who were positive. Majority of the pupils had heavy infection intensities. Swimming was the predominant activity among the pupils along the river, while Bulinus nasutus were the predominant intermediate host for S. haematobium in the study area. Data derived from the study will be availed to the Tana River County authority to be used in the implementation of control programs in the area. The study was also used for early diagnosis by determining the intensity of the infection through egg counts and treatment was offered to the patients to reduce the disease from spreading and becoming chronic. It is recommended that the County government of Tana River to come up with control programs for the snails and infected school going children. Also, it is recommended for large scale screening and treatment for the whole community covering all age groups be carried out to evaluate the risk of transmission from the adult population to children.