Without treatment, the disease is considered fatal. The people most exposed to the tsetse fly and to the disease live in rural areas and depend on agriculture, fishing, animal husbandry or hunting. Sustained control efforts have reduced the number of new cases. In the number reported dropped below 10 for the first time in 50 years, and in there were cases recorded.

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Without treatment, the disease is considered fatal. The people most exposed to the tsetse fly and to the disease live in rural areas and depend on agriculture, fishing, animal husbandry or hunting. Sustained control efforts have reduced the number of new cases. In the number reported dropped below 10 for the first time in 50 years, and in there were cases recorded.

Diagnosis and treatment of the disease is complex and requires specifically skilled staff. Human African trypanosomiasis, also known as sleeping sickness, is a vector-borne parasitic disease. Tsetse flies are found just in sub-Saharan Africa though only certain species transmit the disease. For reasons that are so far unexplained, in many regions where tsetse flies are found, sleeping sickness is not.

Rural populations living in regions where transmission occurs and which depend on agriculture, fishing, animal husbandry or hunting are the most exposed to the tsetse fly and therefore to the disease. The disease develops in areas ranging from a single village to an entire region.

Within an infected area, the intensity of the disease can vary from one village to the next. A person can be infected for months or even years without major signs or symptoms of the disease. When more evident symptoms emerge, the patient is often already in an advanced disease stage where the central nervous system is affected.

First signs and symptoms are observed a few months or weeks after infection. The disease develops rapidly and invades the central nervous system.

Only Uganda presents both forms of the disease, but in separate zones. Another form of trypanosomiasis occurs mainly in Latin America. It is known as American trypanosomiasis or Chagas disease.

Trypanosomiasis in domestic animals, particularly in cattle, is a major obstacle to the economic development of affected rural areas.

However the precise epidemiological role of the animal reservoir in the gambiense form of the disease is not yet well known. Major human epidemics There have been several epidemics in Africa over the last century: one between and , mostly in Uganda and the Congo Basin; one in in a number of African countries; and the most recent epidemic started in and lasted until the late s.

The epidemic was controlled thanks to mobile teams which carried out the screening of millions of people at risk. By the mids, the disease was under control with less than cases reported in the whole continent. After this success, surveillance was relaxed, and the disease reappeared, reaching epidemic proportions in several regions by The efforts of WHO, national control programmes, bilateral cooperation and nongovernmental organizations NGOs during the s and early 21st century reversed the curve.

Disease burden Sleeping sickness threatens millions of people in 36 countries in sub-Saharan Africa. Many of the affected populations live in remote rural areas with limited access to adequate health services, which complicates the surveillance and therefore the diagnosis and treatment of cases.

In addition, displacement of populations, war and poverty are important factors that facilitate transmission. In , almost 40 cases were reported, but estimates were that cases were undiagnosed and therefore untreated. In , after continued control efforts, the number of cases reported dropped below 10 9 for the first time in 50 years. This decline in number of cases has continued with new cases reported in , the lowest level since the start of systematic global data-collection 80 years ago.

The estimated population at risk is 65 million people. Current disease distribution The disease incidence differs from one country to another as well as in different parts of a single country.

Countries such as Burkina Faso, Ghana, and Nigeria, have reported sporadic cases in the last 10 years. Infection and symptoms The disease is mostly transmitted through the bite of an infected tsetse fly but there are other ways in which people are infected: Mother-to-child infection: the trypanosome can cross the placenta and infect the fetus.

Mechanical transmission through other blood-sucking insects is possible, however, it is difficult to assess its epidemiological impact. Accidental infections have occurred in laboratories due to pricks with contaminated needles. Transmission of the parasite through sexual contact has been reported. In the first stage, the trypanosomes multiply in subcutaneous tissues, blood and lymph.

This is also called haemo-lymphatic stage, which entails bouts of fever, headaches, enlarged lymph nodes, joint pains and itching In the second stage the parasites cross the blood-brain barrier to infect the central nervous system.

This is known as the neurological or meningo-encephalic stage. In general this is when more obvious signs and symptoms of the disease appear: changes of behaviour, confusion, sensory disturbances and poor coordination. Disturbance of the sleep cycle, which gives the disease its name, is an important feature. Without treatment, sleeping sickness is considered fatal although cases of healthy carriers have been reported. Disease management: diagnosis Disease management is made in 3 steps: Screening for potential infection.

Diagnosing by establishing whether the parasite is present in body fluids. Staging to determine the state of disease progression. This entails clinical examination and in some cases analysis of the cerebrospinal fluid obtained by lumbar puncture.

Exhaustive screening requires a major investment in human and material resources. In Africa such resources are often scarce, particularly in remote areas where the disease is mostly found. As a result, some infected individuals may die before they can ever be diagnosed and treated. Treatment The type of treatment depends on the form of the disease and the disease stage. The drugs used in the first stage are safer and easier to administer than those for second stage.

Also, the earlier the disease is identified, the better the prospect of a cure. The assessment of treatment outcome requires follow up of the patient up to 24 months and entails clinical assessment and laboratory exams of body fluids including in some cases, cerebrospinal fluid obtained by lumbar puncture, as parasites may remain viable for long periods and reproduce the disease months after treatment.

Treatment success in the second stage depends on drugs that cross the blood-brain barrier to reach the parasite. New treatment guidelines for gambiense human African trypanosmiasis were issued by WHO in In total six different drugs are used for the treatment of sleeping sickness. These drugs are donated to WHO by manufacturers and distributed free of charge to disease endemic countries.

Despite non-negligible undesirable effects, it is in general well tolerated by patients. It provokes certain undesirable effects, including urinary tract and allergic reactions. It is generally used in combination with nifurtimox as part of the Nifurtimox-eflornithine combination therapy, NECT but can be used also as monotherapy. The regimen is complex and cumbersome to apply. Nifurtimox is registered for the treatment of American trypanosomiasis but not for human African trypanosomiasis.

Nevertheless, after safety and efficacy data provided by clinical trials, its use in combination with eflornithine was included in the "WHO List of Essential Medicines". Both drugs are provided free of charge by WHO to endemic countries with a kit containing all the material needed for its administration.

This molecule is indicated as first line for first stage and non-severe second stage. It should be administered within 30 minutes after a solid meal and under supervision of trained medical staff.. Public private partnership In and , WHO established public-private partnerships with Aventis Pharma now Sanofi and Bayer HealthCare which 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.

The partnership was renewed in , and WHO provides the anti-trypanosome medicines free of charge to endemic countries through public-private partnerships with Sanofi pentamidine, melarsoprol, eflornithine and fexinidazole and with Bayer HealthCare suramin and nifurtimox. The conditioning and shipment of medicines is done in collaboration with MSF-Logistics. In , WHO set up a biological specimens bank that is available to researchers to facilitate the development of new and affordable diagnostic tools.

The bank contains samples of blood, serum, cerebrospinal fluid, saliva and urine from patients infected with both forms of the disease as well as samples from uninfected people from areas where the disease is endemic.

In , WHO launched the initiative of the Atlas of human African Trypanosomiasis to map at village level all reported cases. In a coordination network for human African trypanosomiasis 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 the disease, international and non-governmental organizations, and donors.

The objectives of the WHO programme are to: strengthen and coordinate control measures and ensure field activities are sustained; strengthen surveillance systems; ensure accessibility to the diagnosis and the best treatment available; support the monitoring of treatment and drug resistance; develop an information database for epidemiological analysis, including the atlas of the human African trypanosomiasis, completed in collaboration with the Food and Agriculture Organization FAO ; ensure skilled staff by offering training activities; support operational research to improve diagnostic and treatment tools; promote collaboration with the FAO in charge of animal trypanosomiasis and the International Atomic Energy Agency IAEA dealing with vector control through male flies made sterile by radiation.


Trypanosomiasis africana. Enfermedad del sueño

Prognosis[ edit ] If untreated, T. For individuals which are infected by T. For individuals affected by T. Disease progression is rapid and invades the central nervous system, causing death within a short amount of time. The condition has been present in Africa for thousands of years. This changed after Arab slave traders entered central Africa from the east, following the Congo River , bringing parasites along.


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