Control and Surveillance
WHO's ultimate objective is the elimination of human African trypanosomiasis as a public health problem and the implementation of sustained surveillance in all disease-endemic countries.
To achieve this, the HAT control and surveillance programme focuses on:
Providing people at risk with wider access to diagnosis and treatment. There is no universal methodology to control human African trypanosomiasis. Each situation must be assessed separately to develop appropriate strategies and meet local needs. WHO assists 'National Sleeping Sickness Programmes' (NSSCPs) in implementing control activities and capacity building through in-service training and thematic workshops at national and international level. Reagents and equipment for screening and diagnosis and drugs for treatment are also provided.
Strengthening control and surveillance. Control and surveillance of the disease includes active and passive case finding, diagnosis, treatment, follow-up, vector control and control of the animal reservoir. These are performed at different levels and intensity, depending on the epidemiological situation, local and national capacity and environment.
Control and surveillance can involve mobile teams, fixed posts, or both, whereas coordination can be centralized or decentralized, vertical or integrated in the existing health services. Active case finding is carried out by mobile teams in endemic areas. Passive case detection is done in health facilities.
The control and surveillance programme must take into consideration the epidemiological status and the form of the disease, gambiense or rhodesiense. Financial availability, local needs and constraints are also fundamental elements in planning. In addition, geographic, climatic, sociologic and demographic factors as well as problems associated with security and accessibility, staff availability and competence, as well as the structure and performance of health care system must be considered.
Technical support and guidelines. WHO’s approach to efficient and effective surveillance and control operations consists of helping national programmes assess local situations, identify suitable techniques and methodologies, design appropriate structures, develop adapted strategies and implement capacity building activities. Assistance is brought through consultation, training and logistics support. Guidelines are enhanced with participation of field actors and delivered to national implementing bodies. The main objective is to harmonize control strategies and make optimal use of available tools.
- HAT occurs mostly in rural, difficult-to-access areas south of the Sahara and is distributed over wide areas where poverty, social instability, insecurity and weak health systems are predominant;
- The complexity of current tools to combat the disease require staff with strong competence and experience, which limits implementation of control activities in primary health services;
- HAT competes with pandemic diseases and is consigned to a low health priority, receiving little support from health policy makers and donors.
In the 1930s, colonial administrations established large programmes to combat the spread and reduce the prevalence of sleeping sickness. Specialized structures with dedicated staff managed to screen, treat and follow-up millions of individuals in Africa and almost stopped transmission of the disease in the early 1960s.
The rarity of cases led to a loss of interest in surveillance and gradually the disease crept back. In the 1980s a number of flare-ups were observed in previously endemic areas. The greatest challenge to avoid such resurgence is to maintain sustainable control and surveillance capacities. Sustainability can only be achieved through an integration of control and surveillance activities within a reinforced, existing health system. A specialized central structure at national level is necessary to ensure the monitoring, coordination and technical assistance needed.
The recent development of new treatments and diagnostic tools that are more affordable and simpler to implement in the field is bringing us closer to integration and sustainability, but new tools that are better still are needed.
Progress of elimination
WHO has identified two primary indicators to measure the progress towards g-HAT elimination: (i) the number of cases annually reported, and (ii) the number of foci validated as eliminated (i.e. reporting less than 1 case per 10,000 inhabitants per year). Both indicators are to be monitored annually. Monitoring by the latter indicator is planned to start when 2015 data become available.
Secondary indicators are also defined, to assess the intensity and effectiveness of the elimination activities. These include: (i) the geographical distribution of the disease, (ii) the areas and populations at different levels of risk, and (iii) the proportion of the population at risk covered by control and surveillance activities.
- The Human African Trypanosomiasis Control and Surveillance Programme of the World Health Organization 2000–2009: The Way Forward
- The journey towards elimination of gambiense human African trypanosomiasis: not far, nor easy
- Monitoring the Progress towards the Elimination of Gambiense Human African Trypanosomiasis
- Human African trypanosomiasis in the Democratic Republic of the Congo: disease distribution and risk
- Mapping the capacities of fixed health facilities to cover people at risk of gambiense human African trypanosomiasis
- Accelerating work to overcome the global impact of neglected tropical diseases