Human African trypanosomiasis

Cases of sleeping sickness drop to lowest level in 75 years

19 May 2015 | Geneva
©De la Tour
Health worker performing Card Agglutination Trypanosomiasis Test (CATT) to screen villagers at risk.


The number of new cases of human African trypanosomiasis (also known as sleeping sickness) reported to WHO has dropped to 3 796 – the lowest level since the start of systematic global data-collection 75 years ago.

Collaboration with regional offices – the Regional Office for Africa and the Regional Office for the Eastern Mediterranean – has greatly contributed to reducing transmission of the disease. At the height of a resurgence of the disease in 1998, nearly 38 000 cases were reported.

This is a historic achievement” said Dr Jean Jannin, Coordinator, Department of Control of Neglected Tropical Diseases. “We are on track to achieving WHO’s Roadmap target of eliminating the disease as a public health problem by 2020.

Strengthened control and surveillance by National Sleeping Sickness Control Programmes in endemic countries over the past 15 years have progressively reduced the number of cases – falling to below 10 000 cases in 2009 and to 6 314 cases in 2013.

“Reduction in the number of cases could not have been possible without the invaluable support of mobile health units in endemic countries” said Dr José Ramón Franco, Medical Officer. “As cases continue to decline, we are adapting our control programme to the new epidemiological situation, improving surveillance by reinforcing the integration of passive case-finding in the peripheral health system.

In 2014 a coordination network for HAT was established under WHO leadership to ensure strengthened and sustained efforts to eliminate the disease. The stakeholders include national sleeping sickness control programmes, groups developing new tools to fight HAT, international and non-governmental organizations involved in control, and donors.

Collaboration

Since 2000 and 2001, WHO public-private partnerships with Sanofi (formerly Aventis Pharma) and Bayer HealthCare have enabled the creation of a WHO-led control and surveillance programme, providing support to endemic countries in their control activities and the supply of medicines free of charge.

WHO ensures the access of the donated anti-trypanosome medicines to endemic countries through this public-private partnership with Sanofi (pentamidine, melarsoprol and eflornithine) and with Bayer HealthCare (suramin and nifurtimox).

The disease

Human African trypanosomiasis, also known as sleeping sickness, is a vector-borne parasitic disease. It is caused by infection with protozoan parasites belonging to the genus Trypanosoma. They are transmitted to humans by tsetse fly (Glossina genus) bites which have acquired their infection from human beings or from animals harbouring the human pathogenic parasites.

There are two main forms of human African trypanosomiasis: trypanosoma brucei gambiense and trypanosoma brucei rhodesiense. Although there have been several epidemics in Africa over the last century, the disease was brought under control through successive control programmes. By the mid-1960s, less than 5000 cases were reported in the whole continent. But after this success, surveillance was relaxed and the disease re-emerged, reaching epidemic proportions in several regions by 1970.

The efforts of WHO, national control programmes, bilateral cooperation and nongovernmental organizations (NGOs) during the 1990s and the first decade of this century reversed the curve.

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