African trypanosomiasis overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Pilar Almonacid
Overview
Sleeping sickness or African trypanosomiasis is a parasitic disease in people and animals, caused by protozoa of genus Trypanosoma and transmitted by the tsetse fly. The disease is endemic in certain regions of Sub-Saharan Africa, covering about 36 countries and 60 million people.
Historical Perspective
The condition has been present in Africa since at least the 14th century, and probably for thousands of years before that. The causative agent and vector were not identified until 1902–1903 by Sir David Bruce, and the differentiation between protozoa was not made until 1910. The first effective treatment, Atoxyl, an arsenic based drug developed by Paul Ehrlich and Kiyoshi Shiga was introduced in 1910 but blindness was a serious side effect. Numerous drugs designed to treat the disease have been introduced since then. There have been three severe epidemics in Africa over the last century: one between 1896 and 1906, mostly in Uganda and the Congo Basin, one in 1920 in several African countries, and one that began in 1970 and is still in progress. The 1920 epidemic was arrested due to mobile teams systematically screening millions of people at risk. The disease had practically disappeared between 1960 and 1965. After that success, screening and effective surveillance were relaxed and the disease has reappeared in endemic form in several foci over the last thirty years. [1]
Classification
African trypanosomiasis can be classified based upon the pathogen and geographic location into two types East African trypanosomiasis and West African trypanosomiasis.[2]
Epidemiology and Demographics
It is estimated that 50,000 to 70,000 people are currently infected, the number having declined somewhat in recent years.[3]
Natural History, Complications and Prognosis
If left untreated, the patient will develop symptoms of progressive mental deterioration, which is irreversible and eventually lead to death. Common complications that can develop as a result of African trypanosomiasis include anemia, aspiration pneumonia, meningoencephalitis, seizures, coma, perinatal death or abortion (congenital infection). The prognosis of African trypanosomiasis is good with treatment. Without treatment, the mortality rate of African sleeping sickness is close to 100%.[4][5]
Laboratory Findings
The diagnosis of African trypanosomiasis rests upon demonstrating trypanosomes by microscopic examination of chancre fluid, lymph node aspirates,blood,bone marrow, or, in the late stages of infection, cerebrospinal fluid.
Treatment
Medical Therapy
Medical treatment of African trypanosomiasis should begin as soon as possible and is based on the infected person’s symptoms and laboratory results. Medications are the mainstay of treatment for African trypanosomiasis. Pentamidine isethionate and suramin are the drugs of choice to treat the hemolymphatic stage of West and East African Trypanosomiasis, respectively. Melarsoprol is the drug of choice for late disease with central nervous system involvement (infections by T.b. gambiense or T. b. rhodiense). Hospitalization is necessary for the second stage of the disease. Periodic follow-up exams that include a spinal tap are required for 2 years. If a person fails to receive medical treatment for African trypanosomiasis, death will occur within several weeks to months.
Surgery
Surgical intervention is not recommended for the management of African trypanosomiasis.
Prevention
Prevention and control focus on the eradication of the parasitic host, the tsetse fly. Methods of primary prevention of African trypanosomiasis include use of insecticides to control the vector, use of new construction compounds in building walls and roofs, and organ/blood testing prior to donation. Regular active surveillance, involving case detection and treatment, in addition to tsetse fly control, is the backbone of the strategy for control of sleeping sickness
References
- ↑ Template:Cite paper
- ↑ Picozzi K, Fèvre EM, Odiit M, Carrington M, Eisler MC, Maudlin I, Welburn SC (2005). "Sleeping sickness in Uganda: a thin line between two fatal diseases". BMJ. 331 (7527): 1238–41. doi:10.1136/bmj.331.7527.1238. PMC 1289320. PMID 16308383.
- ↑ Template:Cite paper
- ↑ Blum J, Schmid C, Burri C (2006). "Clinical aspects of 2541 patients with second stage human African trypanosomiasis". Acta Trop. 97 (1): 55–64. doi:10.1016/j.actatropica.2005.08.001. PMID 16157286.
- ↑ Levine IM, Jossmann PB, DeAngelis V (1977). "Liorseal, a new muscle relaxant in the treatment of spasticity--a double-blind quantitative evaluation". Dis Nerv Syst. 38 (12): 1011–5. PMID 338269.