SIXTY-FIFTH WORLD HEALTH ASSEMBLY Provisional agenda item 13.11
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Elimination of schistosomiasis Report by the Secretariat
1. The Executive Board at its 130th session in January 2012 considered an earlier version of this report;1 the Board then adopted resolution EB130.R9.2 2. Schistosomiasis remains of significant public health importance, with an estimated 200 million people infected worldwide, 90% of whom live in sub-Saharan Africa. The disease is caused by blood flukes Schistosoma haematobium, S. guineensis, S. intercalatum, S. japonicum, S. mansoni, and S. mekongi. S. haematobium causes urogenital schistosomiasis whereas the other forms cause intestinal disease. 3. In 2001, the Health Assembly, in resolution WHA54.19 on schistosomiasis and soil-transmitted helminth infections, urged Member States inter alia: (1) to sustain successful control activities in low-transmission areas in order to eliminate schistosomiasis and soil-transmitted helminth infections as a public health problem, and to give high priority to implementing or intensifying control of schistosomiasis and soil-transmitted helminth infections in areas of high transmission while monitoring drug quality and efficacy; (2) to ensure access to essential drugs against schistosomiasis and soil-transmitted helminth infections in all health services in endemic areas for the treatment of clinical cases and groups at high risk of morbidity such as women and children, with the goal of attaining a minimum target of regular administration of chemotherapy to at least 75% and up to 100% of all school-age children at risk of morbidity by 2010; (3) to promote access to safe water, sanitation and health education through intersectoral collaboration; (4) to ensure that any development activity likely to favour the emergence or spread of parasitic diseases is accompanied by preventive measures to limit their impact; and (5) to mobilize resources in order to sustain activities for control of schistosomiasis and soil-transmitted helminthiasis. 4. Overall, that goal was not attained. In 2010, only 12.2% of people at risk of schistosomiasis morbidity and 22.8% of school-age children at risk of morbidity due to soil-transmitted helminthiases benefitted from preventive chemotherapy with praziquantel and with benzimidazoles, respectively. Global supplies of praziquantel are insufficient, and this lack of praziquantel is the major barrier to
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See document EB/130/2012/REC/2, summary record of the tenth meeting, section 1.
See document EB130/2012/REC/1 for the resolution, and for the financial and administrative implications for the Secretariat of the adoption of the resolution.
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schistosomiasis control in many endemic countries. Provision of hygiene, sanitation and potable water to at-risk populations has been inadequate in many countries.1 5. Progress was, however, made in expanding schistosomiasis control; the number of those benefitting from preventive chemotherapy with praziquantel rose from 12 million in 2006 to 33.5 million in 2010. This increase was due to greater access to large-scale treatment, for instance through donations of praziquantel and provision of more resources by multiple partners for the control of neglected tropical diseases. The establishment of schistosomiasis control programmes showed that expansion of interventions to national level is feasible in resource-constrained countries. Large-scale schistosomiasis treatment was carried out in 28 countries endemic for the disease in 2010, and several African countries in which the disease is highly endemic achieved morbidity control and have substantially lower levels of transmission. They request guidance on how to proceed towards elimination. 6. In the past few years, several countries classified as endemic for schistosomiasis have reported no new autochthonous cases. Schistosomiasis transmission may therefore be interrupted. Among these countries are the Islamic Republic of Iran, Japan, Jordan, Mauritius, Morocco, Tunisia, and some Caribbean countries and territories. In China, among the 12 provinces in which schistosomiasis has been endemic, five have eliminated the disease and three more have recently achieved targets set for its control. In a few countries in which schistosomiasis is endemic, transmission may be sufficiently low for elimination to be feasible. 7. In Morocco, for example, in 1982 the Ministry of Health launched a national schistosomiasis control programme, whose goal was changed in 1994 to eliminating the disease by 2004. The last autochthonous case of schistosomiasis in the country was detected in 2003. Serological surveys carried out in 2009 confirmed the interruption of S. haematobium transmission.2 Tools for assessment and confirmation of the interruption of schistosomiasis transmission were validated in those surveys. 8. The Secretariat considers that elimination, as envisaged in resolution WHA54.19, is feasible in some epidemiological settings, provided that: there is strong political commitment to the goal; supplies of anthelminthic medicines for preventive chemotherapy are adequate; and support for hygiene, sanitation and water is provided by Member States and the international community. 9. For countries with a high burden of disease, interventions need to be scaled up in order to reduce the morbidity due to schistosomiasis. In countries with control programmes in operation efforts should be intensified to consolidate gains made and to reduce the transmission of schistosomiasis. 10. Where possible, schistosomiasis control measures should be integrated into other disease control programmes and into health systems in order to make efficient use of resources and optimize programme benefits. 11. With progress being made in eliminating schistosomiasis and the validation in some countries of instruments for confirming interruption of transmission, consideration needs to be given to assessing, on request, that the disease has been eliminated from a country.
Bartram J, Cairncross S. Hygiene, sanitation, and water: forgotten foundations of health. PLoS Med, 2010, 7(11):e1000367. Amarir F, El Mansouri B, Fellah H et al. National serologic survey of Haematobium schistosomiasis in Morocco: evidence for elimination. American Journal of Tropical Medicine and Hygiene, 2011, 84(1):15–19. 2
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ACTION BY THE HEALTH ASSEMBLY 12. The Health Assembly is invited to adopt the resolution recommended by the Executive Board in resolution EB130.R9.
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