Elimination of Schistosomiasis Transmission in Zanzibar: Baseline Findings before the Onset of a Randomized Intervention Trial

Knopp, Stefanie; Person, Bobbie; Shaali, M.; Mohammed, Khalfan A.; Ali, Said M.; Khamis, I. Simba; Rabone, Muriel; Allan, Fiona; Gouvras, Anouk N.; Blair, Lynsey; Fenwick, Alan; Utzinger, Jürg; Rollinson, David

doi:10.1371/journal.pntd.0002474

Cited by 71 publications

(93 citation statements)

References 49 publications

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“…The overall prevalence of infection (S. haematobium + S. mansoni) was found to be significantly higher among males than females a situation that has been observed in many other studies in schistosomiasis endemic communities [8,[14][15][16][17][18][19]. The observation by Amuta and Houmsou [15] was explained in terms of higher tendency of water contact activities among males through swimming and washing of clothes.…”

Section: Discussionmentioning

confidence: 56%

Childhood Activities and Schistosomiasis Infection in the Kassena-Nankana District of Northern Ghana

Anto

Asoala²,

Adjuik³

et al. 2014

J Infect Dis Ther

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Schistosomiasis is a common cause of morbidity especially among rural children in less developed countries. The extent and distribution of schistosomiasis infection among school-age children was assessed and the association between some childhood activities and prevalence of infection was determined in northern Ghana. A cross-sectional study was conducted during which stool and urine samples were collected from children 6-15 years. Samples were analysed using the Kato-Katz technique and the 10 ml urine filtration methods respectively. Data on water contact activities were also collected. The level of infection was compared in relation to location and water contact activities. A total of 1,764 children participated in the study. Prevalence of Schistosoma haematobium infection was 18.9%. The highest level of infection (33.1%) was found among children resident in the southern part of the district, the lowest among those in the eastern (3.6%) and northern (3.8%) parts. S. mansoni infection was 10.9%. The highest level of S. mansoni infection (54.2%) was found among children resident in the central part of the district. The overall prevalence of infection (S. haematobium+S. mansoni) was moderate (27.1%). More males (32.5%) than females (20.2%) were infected (χ 2 =32.8, P<0.0001). Children aged 9-12 years had the highest prevalence of infection (31.8%; 95% CI: 28.4-35.5) with the lowest among those aged 6-8 years (23.9%; 95% CI: 20.2-28.0). Swimming in the canals (χ 2 =404.4, P<0.0001) and working on tomato farms (χ 2 =37.7, P<0.0001) were risk factors for infection. Herding cattle appeared to have protected the children from infection (χ 2 =34.8, P=0.0001). Schistosomiasis is prevalent throughout the district with children resident in the central and southern parts of the district being more at risk of infection. There is the need to put in place an integrated and effective schistosomiasis control programme.

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Section: Discussionmentioning

confidence: 56%

Childhood Activities and Schistosomiasis Infection in the Kassena-Nankana District of Northern Ghana

Anto

Asoala²,

Adjuik³

et al. 2014

J Infect Dis Ther

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“…Infection hot-spots, however, do still occur (Knopp et al, 2013b;Hardy et al, 2015). In the case of urogenital schistosomiasis, the overall prevalence in Zanzibar was recently reported to be less than 10%, with infection intensities also being found to be low in 2013, but in some shehias more than 20% of the surveyed population (children and adults) were infected with S. haematobium (Knopp et al, 2013a).…”

Section: Study Settingmentioning

confidence: 99%

Community Co-Designed Schistosomiasis Control Interventions for School-Aged Children in Zanzibar

et al. 2016

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SummaryTop-down biomedical interventions to control schistosomiasis in sub-Saharan Africa have had limited success, primarily because they fail to engage with the social, political, economic and ecological contexts in which they are delivered. Despite the call to foster community engagement and to adapt interventions to local circumstances, programmes have rarely embraced such an approach. This article outlines a community co-designed process, based upon Human-Centered Design, to demonstrate how this approach works in practice. It is based on initial work undertaken by social science researchers, public health practitioners and community members from the Zanzibar Islands, Tanzania, between November 2011 and December 2013. During the process, 32 community members participated in a qualitative and quantitative data-driven workshop where they interpreted data on local infections from S. haematobium and co-designed interventions with the assistance of a facilitator trained in the social sciences. These interventions included the implementation of novel school-based education and training, the identification of relevant safe play activities and events at local schools, the installation of community-designed urinals for boys and girls and the installation of community-designed laundry-washing platforms to reduce exposure to cercariae-contaminated fresh water. It is suggested that the a community co-designed process, drawing from Human-Centered Design principles and techniques, enables the development of more sustainable and effective interventions for the control of schistosomiasis.

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“…For example, due to successful control efforts over the past decades, the number of malaria cases has drastically declined [1, 2], the Tsetse fly has disappeared [3], and the transmission of lymphatic filariasis has been reduced to very low levels [4, 5]. Also urogenital schistosomiasis that imposed a considerable public health problem and formerly occurred with a very high prevalence on both islands [6–11], is now targeted for elimination [12–14]. …”

Section: Introductionmentioning

confidence: 99%

Urogenital schistosomiasis transmission on Unguja Island, Zanzibar: characterisation of persistent hot-spots

et al. 2016

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BackgroundElimination of urogenital schistosomiasis transmission is a priority for the Zanzibar Ministry of Health. Preventative chemotherapy together with additional control interventions have successfully alleviated much of the disease burden. However, a persistently high Schistosoma haematobium prevalence is found in certain areas. Our aim was to characterise and evaluate these persistent “hot-spots” of transmission and reinfection in comparison with low-prevalence areas, to support the intervention planning for schistosomiasis elimination in Zanzibar.MethodsPrevalences of S. haematobium were annually determined by a single urine filtration in schoolchildren from 45 administrative areas (shehias) in Unguja in 2012, 2013 and 2014. Coverage data for biannual treatment with praziquantel were available from ministerial databases and internal surveys. Among the 45 shehias, five hot-spot (≥ 15 % prevalence) and two low-prevalence (≤ 5 %) shehias were identified and surveyed in mid-2014. Human-water contact sites (HWCSs) and the presence of S. haematobium-infected and uninfected Bulinus globosus, as well as safe water sources (SWSs) and their reliability in terms of water availability were determined and mapped.ResultsWe found no major difference in the treatment coverage between persistent hot-spot and low-prevalence shehias. On average, there were considerably more HWCSs containing B. globosus in hot-spot than in low-prevalence shehias (n = 8 vs n = 2) and also more HWCSs containing infected B. globosus (n = 2 vs n = 0). There was no striking difference in the average abundance of SWSs in hot-spot and low-prevalence shehias (n = 45 vs n = 38) and also no difference when considering SWSs with a constant water supply (average: 62 % vs 62 %). The average number of taps with a constant water supply, however, was lower in hot-spot shehias (n = 7 vs n = 14). Average distances from schools to the nearest HWCS were considerably shorter in hot-spot shehias (n = 229 m vs n = 722 m).ConclusionThe number of HWCSs, their infestation with B. globosus and their distance to schools seem to play a major role for a persistently high S. haematobium prevalence in children. In addition to treatment, increasing access to reliably working taps, targeted snail control at HWCSs near schools and enhanced behaviour change measures are needed to reduce prevalences in hot-spot areas and to finally reach elimination.Trial registration ISRCTN48837681.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1847-0) contains supplementary material, which is available to authorized users.

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Elimination of Schistosomiasis Transmission in Zanzibar: Baseline Findings before the Onset of a Randomized Intervention Trial

Cited by 71 publications

References 49 publications

Childhood Activities and Schistosomiasis Infection in the Kassena-Nankana District of Northern Ghana

Childhood Activities and Schistosomiasis Infection in the Kassena-Nankana District of Northern Ghana

Community Co-Designed Schistosomiasis Control Interventions for School-Aged Children in Zanzibar

Urogenital schistosomiasis transmission on Unguja Island, Zanzibar: characterisation of persistent hot-spots

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