Neglected tropical diseases

Schistosomiasis: WHO reports substantial treatment progress for school-age children

Adolescent girls and women are important target populations due to increasing recognition of the burden posed by female genital schistosomiasis

08 December 2017 | Geneva −− Data published by the World Health Organization (WHO) today show that almost 90 million individuals were treated for schistosomiasis in 2016, including 70.9 million school-age children and 18.3 million adults.

The data show substantial progress in 2016 to reach almost 54% global coverage, with an impressive 57% coverage in the African Region due to expansion of control interventions,” said Dr Ren Minghui, WHO Assistant Director-General for Communicable Diseases. “The global target set in WHO’s roadmap on neglected tropical diseases is to reach at least 75% of all school-age children in endemic areas by 2020."

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The highest burden of schistosomiasis is found in the WHO African Region, where almost 9 out of 10 people requiring treatment for the disease live. Of the 41 countries where treatment is needed, 30 reported data to WHO in 2016; 12 countries1 achieved 75% treatment coverage.

Female genital schistosomiasis

Female genital schistosomiasis (FGS) is predominantly caused by infection with Schistosoma haematobium. Women suffer severe morbidity during their reproductive years. Infection is transmitted by schistosome eggs that penetrate the urinary system, migrate to the female genital region and form granulomas in the uterus, fallopian tubes and ovaries, leading to the development of uterine enlargement, menstrual disorders, inflammation of the cervix and infertility.

Several studies, including a recent cohort study, suggest that young women infected with schistosomiasis have a higher chance of acquiring HIV” said Michel Sidibé, Executive Director of UNAIDS and current Chair of H62 . “Female genital schistosomiasis is a seriously neglected disease that should be included in a woman-centred approach to sexual and reproductive health and rights that also includes HIV prevention and treatment, cervical cancer prevention, contraceptive choice and gender-based violence programmes.”

It is estimated that between 20 – 56 million young and adult women suffer from FGS.

Little attention is given to women and the risks FGS poses,” said Dr Amadou Garba, Scientist, Schistosomiasis Control Programme, WHO Department of Control of Neglected Tropical Diseases. “It is important to decrease the disease burden and implement prevention measures during childhood and adolescence. If programmes can target adolescent girls and women, the likelihood of improving their reproductive life and well-being will be much higher.”

Women who have been treated with praziquantel at least once in their lifetime have been found to be 50% less likely to develop FGS later in life. Furthermore, studies3 have demonstrated that pregnant women with schistosomiasis infection are likely to develop severe anaemia, have low birth weight infants, and risk a higher infant and maternal mortality rate.

The need to treat adults

Given the large burden of schistosomiasis among adults, particularly among occupational groups and women who are in contact with infected water due to domestic activities, entire communities in high-risk areas should receive treatment.

Given the large burden of schistosomiasis among adults, particularly among occupational groups and women who are in contact with infected water due to domestic activities, entire communities in high-risk areas should receive treatment.

Based on reports from countries, an estimated 95.2 million adults are living in areas where treatment is required for schistosomiasis. In 2016, 18.3 million adults were treated in 23 countries. Due to insufficient donation and procurement of praziquantel, the current global coverage for adults represents only 14.3%.

WHO’s strategy to control schistosomiasis focuses on reducing transmission of the disease through periodic, targeted treatment with praziquantel through large-scale treatment of affected populations. In some countries, such as Egypt, mass treatment has reduced the infection rate to less than 1%.4

WHO recommends treatment of adults as well as pregnant women (except during the first trimester) and lactating women5 for schistosomiasis.

Although the current schistosomiasis control strategy is based on large-scale treatment of at-risk population groups, providing wider access to safe water, improved sanitation and hygiene education are considered long-term solutions.


1Burkina Faso, Burundi, Cameroon, Côte d’Ivoire, Guinea, Mali, Malawi, Mozambique, Swaziland, Togo, United Republic of Tanzania and Zimbabwe.
2H6 is a partnership that unites and leverages the mandates of 6 United Nations agencies (UNAIDS, UNFPA, UNICEF, WHO, UN Women and the World Bank) to deliver on an integrated agenda for the health and well-being of women, children and adolescents.
3Friedman JF, Mital P, Kanzaria HK, Olds GR, Kurtis JD. Schistosomiasis and pregnancy. Trends Parasitol. 2007;23:159–164 (https://www.ncbi.nlm.nih.gov/pubmed/17336160); Downs JA, Dupnik KM, van Dam GJ, Urassa M, Lutonja P, Kornelis D et al. Effects of schistosomiasis on susceptibility to HIV-1 infection and HIV-1 viral load at HIV-1 seroconversion: a nested case-control study. PLoS Negl Trop Dis. 2017;11(9):e0005968 (https://www.ncbi.nlm.nih.gov/pubmed/28945756); Christinet V, Lazdins-Helds JK, Stothard JR, Reinhard-Rupp J. Female genital schistosomiasis (FGS): from case reports to a call for concerted action against this neglected gynaecological disease. Int J Parasitol. 2016;46(7):395–404 (https://www.ncbi.nlm.nih.gov/pubmed/27063073).
4Applies to parasitological prevalence, as per detection of Schistosoma spp. eggs in urine and stool samples. Report of the WHO Informal Consultation on the use of praziquantel during pregnancy/lactation and albendazole/mebendazole in children under 24 months. Geneva, 8–9 April 2002. Geneva: World Health Organization; 2002 (http://apps.who.int/iris/bitstream/10665/68041/1/WHO_CDS_CPE_PVC_2002.4.pdf).
5Report of the WHO Informal Consultation on the use of praziquantel during pregnancy/lactation and albendazole/mebendazole in children under 24 months. Geneva, 8–9 April 2002(http://apps.who.int/iris/bitstream/10665/68041/1/WHO_CDS_CPE_PVC_2002.4.pdf).

Ashok Moloo

WHO/HTM/NTD
Telephone: +41 22 791 1637
Mobile phone: +41 79 540 50 86
molooa@who.int