Human African Trypanosomiasis (HAT) control

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Disease description and causality

hatHuman African Trypanosomiasis (HAT), also known as ‘sleeping sickness’, is a vector-borne parasitic disease. It is transmitted through bites from the tsetse fly. Human African
trypanosomiasis takes two forms, depending on the parasite involved:

  1. Trypanosoma brucei gambiense (T.b.g.) found in west and central Africa, currently accounts for over 95% of reported cases of sleeping sickness and causes a chronic infection.
  2. Trypanosoma brucei rhodesiense (T.b.r.) found in eastern and southern Africa represents less than 5% of reported cases and causes an acute infection.

Sleeping sickness progresses through two stages and is characterized by bouts of fever, headaches, joint pains and itching followed by confusion, sensory disturbances and poor coordination. Disturbance of the sleep cycle, which gives the disease its name, is an important feature of the disease. Without treatment, sleeping sickness is fatal.

Disease burden and distribution and impact

HAT is the only vector-borne parasitic disease with a geographical distribution limited to the African continent. Cases are reported from about 250 foci in 36 endemic countries of Sub- Saharan Africa. Sleeping sickness threatens millions of people
living in remote rural areas with limited access to adequate health services.

The risk of getting sleeping sickness infection is mainly for people who carry out activities that bring them into contact with tsetse flies like fishing, gathering wild honey, fetching water from rivers, herding cattle, collecting firewood from
forests/woodlands, etc.

The social and economic impact of HAT is often underestimated. Previous epidemics led to abandonment of fertile tracts of land. Most of the countries affected by HAT have agriculture-based economies coupled with this is the fact that HAT mainly affects the most productive age group [15-45 years]. Sleeping sickness therefore decreases manpower and reduces the amount of land cultivated hence impeding development.

Progress in the last 10 years

  • Reduction of HAT burden to less than 10000 cases in 2010
  • Assessment of the epidemiological status in 28 countries
  • Establishment of HAT control programmes in 24 endemic countries
  • Reinforcing of operational capacity of national HAT control programmes
  • Training of staff from 23 countries on programme management, diagnosis and treatment
  • Improvement of access to and availability of safe and simple treatment
  • Development of the HAT atlas for the period 2000–2009

Programme goals and objectives

The ultimate goal of the WHO programme is the elimination of the disease as a public health problem by 2020. The objectives are to:

  • Strengthen operational capacities of national HAT control programmes;
  • Strengthen existing surveillance systems, monitoring and evaluation;
  • Support operational research to improve treatment and diagnostic tools; and
  • Promote inter sectorial collaboration and coordination in vector and reservoir control.

Targets and milestones

The targets and milestones for HAT are to:

  • Eliminate the disease in 80% of foci by 2015; and
  • Achieve elimination as public health problem in 100% of foci by 2020

Major operational strategies

Surveillance and treatment of infected persons is the main strategy for controlling epidemics of Trypanosomiasis whilst vector and reservoir control is the main focus for elimination of the disease. It proposes an integrated approach consisting of continuous surveillance of the population at risk, passive and active case detection and treatment, reduction of animal reservoirs through selective or mass treatment of livestock, and intense tsetse control in highly endemic and epidemic areas.

The type of treatment depends on the stage of the disease. The drugs used in the first stage of the disease are of lower toxicity and easier to administer. Treatment success in the second stage depends on a drug that can cross the blood-brain barrier to reach the parasite. Such drugs are toxic and complicated to administer. Five drugs are registered for the treatment of sleeping sickness and provided free of charge to endemic countries: pentamidine and suramin for first stage treatment; and melarsoprol, eflorithine and a combination of nifurtimox and eflornithine for phase II.

Major partners

African Union Inter-African Bureau for Animal Resources (AU-IBAR), FAO, International Atomic Energy Agency (IAEA), Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC), Programme Against African Trypanosomiasis (PAAT), UNICEF, UNDP, World Bank, UNICEF-UNDP-World Bank- WHO Special Programme for research and training in Tropical Diseases (TDR) and private partners Sanofi and Bayer.

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Global Fact sheet on Human African trypanosomiasis (sleeping sickness)