There was a general increase in trend of cases from 7-12 years then decline among older ages. Gryseels et al. (2006) and Ndamba et al. (1998) reported that those aged between 8-15 years most affected with schistosomiasis with higher infection rates in children than in adults[8, 9]. In a study done in Kenya, Shimada et al. (1987), reported the highest prevalence of schistosomiasis is among children and young adults in many communities, because they are more likely to frequently use river sources for recreational purposes. In our study, there were more females than there were males. This was possibly because the female pupils spent more time in contact with contaminated dam water while swimming, washing, bathing and they also did fishing using nets[11, 12].
There were significant associations between having a current schistosomiasis infection and participating in swimming, bathing in the dam, fishing using a fishing line and fishing with legs in water. This shares similar findings with a water contact observation study done by Chandiwana et al. (1987) where water contact activities such as bathing and recreational and personal use were identified as the risks of contracting schistosomiasis. Other activities in Kwite such as brick molding and watering the garden using dam water were all common practices. We also noted that the school pupils did go for swimming in the dam during break time and after school, they did fetch water for the school garden from the dam. These activities predisposed the school children to getting infected with schistosomiasis.
We observed S. hematobium in urine 31% of samples that were collected. Of note is that 9.5% of cases alluded to having passed bloody stools and the isolation of Biomphalaria pfeifferi snail species in Kwite dam was suggestive that S. mansoni could be a possible cause of schistosomiasis in Kwite. Stool samples could have been done to confirm S.mansoni in Kwite. Bulinus globosus snails that were seen were responsible for transmission of S. hematobium. Midzi et al. (2014), reported that S. hematobium was more widely distributed in Matabeleland South province.
Knowledge levels on causes of disease were high among the pupils while it was lacking on prevention of schistosomiasis. There is thus need to spread messages through health education aided by IEC materials in Kwite. Educational programs can improve knowledge about the disease and healthcare seeking, but behavior can be difficult to change without other options for water contact. The Kwite village’s main source of water for drinking was from the dam during the preceding six months as the three boreholes in the area had broken down. The toilet coverage in the village was lowest at 49% compared to an average of 80% in other villages of Empandeni ward. The provision of safe water supplies and latrines is useful, but for the prevention of schistosomiasis, safe contact sites are also needed.
To control schistosomiasis, strategies include indiscriminate mass treatment, snail control, active case finding, and treatment of particular risk groups such as school-aged children, snail control and health education[1, 2, 15]. However, there were no Information Education and Counseling materials specifically for schistosomiasis the health centre or in the community.
Population-based treatment is feasible, safe, and effective. The main technical difficulty lies in identification of remaining cases and pockets through an integrated surveillance and response system. Mollusciding was done in Kwite dam though surveillance need to be maintained. Molluscides used to eliminate snails in freshwater sources may harm other aquatic lives and, if treatment is not sustained, the snails may return to those sites afterwards. Therefore there is need to maintain surveillance on snail populations on the same note identifying biological methods of controlling snails.
The district was well prepared for the outbreak as surveillance meetings were being held at the rural health centre and at the district. Surveillance minutes and schistosomiasis line lists at the rural health centre and the district offices were seen and verified to be up to date. Integrated disease surveillance and response trainings were done to the district managers but were not extended to the rural health centre staff.
The outbreak response by the district was as per stipulated guidelines. The district was notified by the health centre per phone on the 20th of June 2012. The DMO activated the rapid response team on the same day which was dispatched to investigate the suspected outbreak. Within 48 hours a concrete response was mounted by the district outbreak investigation team at Kwite village.
All 242 pupils present on the day were given Mass Drug Administration (MDA) with praziquantel. Mollusciding was done at the dam to control snails. Health education was intensified to both school pupils and the community on the need to avoid human-contaminated water interface[16, 17]. Follow up of schistosomiasis surveillance was taken up by the district health officials who were scheduled to conduct repeat MDA and controlling snails in the Kwite dam. The provincial health team adopted as on-going activities, the inclusion of schistosomiasis prevention and control in malaria pre-elimination activities.