Protecting children from schistosomiasis in Tanzania

By Access and Delivery Partnership

ADP is helping to ensure that preventive medication for NTDs such as schistosomiasis reaches children in vulnerable areas. Photo: Natasha Scripture/UNDP

Schistosomiasis—also known as ‘bilharzia’ or ‘snail fever’—is a parasitic disease carried by freshwater snails.

It is one of the most widespread neglected tropical diseases (NTDs), with huge socio-economic and health burdens. Estimates show that almost 240 million people around the world required treatment for schistosomiasis in 2019.[1] The vast majority of these infections occur in sub-Saharan Africa, where over 172 million children under 5 are at risk of infection.[2]

Insufficient hygiene and activities such as swimming or fishing in infested water make children especially vulnerable to infection. The disease is also more common in poor communities without adequate access to safe drinking water and sanitation.

In Tanzania, more than 50 percent of the population are at risk of contracting schistosomiasis, primarily in the lake basin regions of Lake Victoria, Lake Tanganyika and Lake Nyasa. It is estimated that as many as 6 million children under the age of 5 in Tanzania are at risk of schistosomiasis infection. In 2019, 53,316 children under 5 were found to be infected, accounting for 1,086 disability-adjusted life years.[3]

Schistosomiasis life cycle

Source: Adapted from a figure by Pearson Education, Inc., publishing as Benjamin Cummings (2004).

Abdominal pain, diarrhoea and blood in the stool or urine are common symptoms of schistosomiasis. The effects on children can be dire—causing anaemia, stunting and impaired learning. Thankfully, the effects are usually reversible with treatment.

The primary method for controlling schistosomiasis, as recommended by the World Health Organization (WHO), is periodic and targeted large-scale treatment (referred to as mass drug administration) of at-risk populations with the medicine praziquantel. Mass drug administration for the prevention of NTDs is one of the most cost-effective interventions in global public health.

For many years the Government of Tanzania has implemented such large-scale population treatment campaigns, often distributed at schools. However, children under the age of 5 at risk of schistosomiasis in Tanzania have not been covered by the mass treatment campaigns due to the lack of a suitable treatment formulation for their age group.

Protecting children from schistosomiasis in Tanzania

The Global Health Innovative Technology (GHIT) Fund has provided funding support to the Pediatric Praziquantel Consortium for the development of a potential treatment option suitable for younger children, including infants and toddlers. The treatment—arpraziquantel—is currently in preparation for the required regulatory approvals and is expected to be available for use in 2024.

In advance of the treatment becoming available and being recommended for use, the Access and Delivery Partnership (ADP) is helping Tanzania to prepare for its timely introduction and delivery by strengthening relevant national capacities. This is in recognition of the fact that even when a new health technology has been developed, ensuring effective introduction and delivery to patients requires a combination of policy and regulatory measures, coupled with effective procurement and supply chain management at the national level.

To achieve this, ADP is working closely with stakeholders across different sectors, including the Ministry of Health, the National Institute for Medical Research (NIMR) and WHO, and is supporting the Strengthening Capacity of the Health System to be Ready for Delivery and Uptake of the Pediatric Praziquantel Formulation for Schistosomiasis (STEPPS) project in Tanzania.

“Schistosomiasis infections among children under 5 years of age is a public health concern in Tanzania. It’s imperative that we are ready to introduce arpraziquantel effectively and in a timely manner, as soon as it is approved and available,” said Dr. Paul Kazyoba from NIMR. “At the National Institute for Medical Research, we have engaged with development partners, as well as decision- and policymakers, for a multisector approach to achieve this.”

To establish the precise magnitude of schistosomiasis infection among children under 5 years of age, especially in regions where data are lacking, an epidemiological study is being conducted by NIMR with support from Tackling Infections to Benefit Africa. This information will be used to estimate initial quantities of the drug to be procured, and related costs.

Among the notable achievements of the STEPPS project has been the identification of an appropriate delivery model—through the existing countrywide de-worming programme.

In addition, more than 300 health workers from across 20 districts have been trained on the use of a safety monitoring and response system for adverse drug reactions associated with praziquantel. And the efficiency and reliability of the supply chain for NTD medicines have been improved through the development of tools and guidelines that have strengthened the capacity of 3,000 community health workers who conduct the large-scale treatment campaigns.

The STEPPS project is also working to raise community awareness of schistosomiasis infection among young children, and of the potential availability and importance of uptake of the pediatric formulation.

The efforts of ADP to help Tanzania successfully control schistosomiasis are ongoing. Once the goals are attained, it is hoped that lessons learned will be instructive for other countries in the region and beyond.

Further information:

Pediatric Praziquantel Consortium

Pediatric Praziquantel Consortium, ‘The Pediatric Praziquantel Consortium Announces Positive Phase III Results for Arpraziquantel To Treat Schistosomiasis’, 16 November 2021

JAGntd and GHIT Fund, ‘Webinar Series 3: Country’s Perspective: Introduction of Pediatric Praziquantel for Schistosomiasis in Tanzania’, 18 November 2021

WHO, ‘Ending the neglect to attain the Sustainable Development Goals: A road map for neglected tropical diseases 2021–2030’, 28 January 2021

This is part of a collection of impact stories highlighting the work of the Access and Delivery Partnership in ensuring access to health technologies for those in need. For more information and to read additional impact stories, please visit the ADP website.

Footnotes

[1] World Health Organization, ‘Schistosomiasis: Key facts’, https://www.who.int/news-room/fact-sheets/detail/schistosomiasis. [2] Figure is based on data from WHO (Maternal, newborn, child and adolescent health and ageing data portal: https://www.who.int/data/maternal-newborn-child-adolescent-ageing/indicator-explorer-new/mca/under-five-population-(thousands); and ‘Schistosomiasis: Status of schistosomiasis endemic countries’: https://apps.who.int/neglected_diseases/ntddata/sch/sch.html) and the Institute for Health Metrics and Evaluation, University of Washington, ‘Global Burden of Disease Study 2019’: https://vizhub.healthdata.org/gbd-results/. [3] Institute for Health Metrics and Evaluation, University of Washington, ‘Global Burden of Disease study 2019’, https://vizhub.healthdata.org/gbd-results/.