Schistosomiasis in Zambia: a systematic review of past and present experiences

Abstract

BackgroundThe speedy rate of change in the environmental and socio-economics factors may increase the incidence, prevalence and risk of schistosomiasis infections in Zambia. However, available information does not provide a comprehensive understanding of the biogeography and distribution of the disease, ecology and population dynamics of intermediate host snails. The current study used an information-theoretical approach to understand the biogeography and prevalence schistosomiasis and identified knowledge gaps that would be useful to improve policy towards surveillance and eradication of intermediate hosts snails in Zambia.MethodsTo summarise the existing knowledge and build on past and present experiences of schistosomiasis epidemiology for effective disease control in Zambia, a systematic search of literature for the period 2000–2017 was done on PubMed, Google Scholar and EBSCOhost. Using the key words: ‘Schistosomiasis’, ‘Biomphalaria’, ‘Bulinus’, ‘Schistosoma mansoni’, ‘Schistosoma haematobium’, and ‘Zambia’, in combination with Booleans terms ‘AND’ and ‘OR’, published reports/papers were obtained and reviewed independently for inclusion.ResultsThirteen papers published in English that fulfilled the inclusion criteria were selected for the final review. The papers suggest that the risk of infection has increased over the years and this has been attributed to environmental, socio-economic and demographic factors. Furthermore, schistosomiasis is endemic in many parts of the country with infection due to Schistosoma haematobium being more prevalent than that due to S. mansoni. This review also found that S. haematobium was linked to genital lesions, thus increasing risks of contracting other diseases such as HIV and cervical cancer.ConclusionsFor both S. haematobium and S. mansoni, environmental, socio-economic, and demographic factors were influential in the transmission and prevalence of the disease and highlight the need for detailed knowledge on ecological modelling and mapping the distribution of the disease and intermediate host snails for effective implementation of control strategies.Electronic supplementary materialThe online version of this article (10.1186/s40249-018-0424-5) contains supplementary material, which is available to authorized users.

Clinical morbidity associated with Schistosoma haematobium infection in pre‐school age children from an endemic district in Zimbabwe

“…Chronic exposure to inflammatory markers has been associated with malnutrition [45]. In this study, we report that malnutrition and stunting had the lowest attributable factors even though they are the most frequently described in association with schistosomiasis morbidity [1,5,8,15,22,27,43]. The strength of this study included the fact that although the calculated sample size was 368, we managed to enrol participants.…”

“…Trapped eggs in the human body systems cause much of the morbidity [14]. The life cycle of S. haematobium involves an asexual reproduction phase which occurs in snails of the genus Bulinus, and the sexual reproduction phase which occurs in human hosts [15]. S.haematobium penetrates the human skin as cercariae and loses its tail and becomes a schistosomulum [16].…”

Cancer in Africa 2018: The role of infections

“…The wider availability of praziquantel at affordable prices has resulted in progress towards Schistosomiasis control in many countries, although progress is uneven. In some countries, there are real prospects for transition from control into interruption of transmission and ultimately elimination, while some authors predict increasing incidence rates of schistosomiasis for the future due to climate change effects, with rising temperature fostering the spread of the parasites …”

“…In some countries, there are real prospects for transition from control into interruption of transmission and ultimately elimination, 43 while some authors predict increasing incidence rates of schistosomiasis for the future due to climate change effects, with rising temperature fostering the spread of the parasites. 44…”

Association of Schistosoma haematobium Infection Morbidity and Severity on Co-infections status in Pre-school Age Children Living in a Rural Endemic Area in Zimbabwe

“…In sub-Saharan Africa alone, about 52 endemic countries reported moderate to high prevalence (4). Individuals living in schistosomiasis-endemic areas are often at risk to several pathogens simultaneously (5). These coinfections could arise due to chance because of host susceptibility or co-circulation of various disease agents (6).…”