Observations on the Transmission Pressure of Schistosomiasis and Soil Transmitted Helminthes in El Kiryab Scheme, Khartoum State

This investigation was designed and conducted in EL Kiryab village to determine the relationship between biological, socioeconomic, behavioural, and microepidemiological aspects affecting the transmission pressure of Bilharzia and soil transmitted helminthes. The surveys ensured the microscopic detection of both S. haematobium and S. mansoni infections as well as some sporadic cases of intestinal helminthes. The total prevalence of Bilharzia among the villagers was 34.2%, where 23.7% were infected by S. haematobium, 18.2% by S. mansoni and 7.7% were suffering from mixed infection. In terms of the prevalence of infection, the most suffering villagers in El Kiryab village was EL Galaa residential site, 44.9%, while the least was Tayba, 17.8%. The study verified significant genderized variations in the prevalence rates of the infection among the villagers and the school children, where the anticipated findings were expounded on basis of water-contact activities. Two epidemiological surveys were conduct, preand post-intervention among El Kiryab school-children, where the overall prevalence rate was 66.5% before treatment, 48.4 % in post-interventions. Utilizing chemotherapy and intensive health education, successfully, 27.1% of the infected school children were cleaned from Bilharzia. From the genderized point of view, the reduction rates among the females, 47.9%, significantly outnumbered those among the males, 13.8%. The overall prevalence and intensity of infection varies with age-classes, the peak of prevalence was observed in the age-group (11-20) years. Thenafter, the peak declined with increasing age, but remained high, while the intensity verified another minor peak in the age-group of more than 50 years, in S. haematobium infection. Regarding the S. mansoni intensity, two major peaks were monitored in the age-groups (21-30) and (41-50) years. These trends were accepted considering the population formula and composition of the migratory workers, who serve as agricultural labourers in the scheme. This fact was furtherly confirmed by the figures of the overall prevalence and intensity related to the various occupational categories. In fact, the miserable situation of infection among the migratory workers could be focused within the frame of two basic observations. First, the bulk of the migratory workers arrived from high endemic areas of the country, second, they used to crop sweat potatoes in the scheme, which needs substantial water-contacts for farming and harvest. The findings suggested that 90.5% of the important water-contacts were performed by the males, while the relatively unimportant contacts were almost equaldistributed between the males and the females, 44.4% and 55.6%, respectively. The study proved that water contact is heterogeneous between sex, age, and that type of activity is the major variable affecting water-contact pattern. The agespecific curves for water-contact activities is similar to the curve of prevalence of schistosomiasis, with a peak at age (11-20) years, then declined. Considering the socioeconomic status of the households, in symphony to the accessibility of latrines and water-supply systems, the number of rooms and the quality of building were significantly correlated to the two infection parameters. Regarding the villagers KAP, the survey highlighted that (80.1%) of the villagers used to lubricate their bodies by variant natural oils, before sleeping. The villagers who used to lubricate their skins ensured to have infection rate double those not lubricating, 44.0% to 22.4%. Very unfortunately, 73.7% of the surveyed samples used to lubricate their bodies by sesame oil. The findings were discussed within the frame of the community believes and practices of the green medicine as well as the attraction of swimming cercariae by sesame oil. The monthly malacological monitory ensured seasonal variations in Biomphalaria pfeifferi and Bulinus truncatus population and infection rates were influenced by the rainfall and temperature and the associated factors. The two snail species were gradually increased to peak at June-July, where they suddenly declined in the subsequent three months. The frequencies of the infected snails were increased gradually from April to peak at May-June, then declined to non-existence at September-February. The study proved that the cercarial shedding pattern of S. mansoni and S. haematobium does not differ from those reported by other workers. It is very crucial to stress that the frequencies of the liberated cercariae from the naturally infected Bul. truncatus were of around 2.5 folds those of the laboratory infection. Regardless of the Schistosoma species as well as being naturally or laboratory infected, cercarial rhythm have the same diurnal patterns of emission. The emitted cercariae of Bul. truncatus increased gradually from commencement to peak at (1101 PM), thenafter declined gradually to complete disappearance at around sun set. On the other hand, the pattern of the cercariae liberated from Biom. pfeifferi symphonized the aforementioned above trend, in spite of peaking earlier, (09 11 AM). Although the dwarf-worm infection significantly outnumbered other helminthic infection among the school children, others were detected like: Enterobius vermicularis, Taenia sagenata and Strongyloides stercoralis. The same infections were monitored among the villagers although the infection parameters skewed to lowest figures. various determinants influencing the transmission pressure and the non-uniform distribution of schistosomiasis in the endemic areas were discussed within the frame of the obtained findings. Finally, based on the results of the surveys, some effective measures for combating the disease in El Kiryab area were highly recommended.