The lecture today will be on trypanosomiasis vectors, which mainly include the tsetse fly. Its two causative agents, trypansoma brucei gambiense and trypanosoma brucei rhodesiense, lead to different courses of disease, with t. Chemotherapy for secondstage human african trypanosomiasis pdf. Human african trypanosomiasis hat, commonly referred to as sleeping sickness, is a protozoan parasitic infection transmitted by the tsetse fly. The organism t cruzi and infection in humans were first described in 1909 by the brazilian physician carlos r. Epidemiology of human african trypanosomiasis clep. The epidemiology of trypanosomiasis in a tsetseinfested range area of kenya was studied for 2 years in various breeds of sheep and goats. The major vector is the tsetse fly, which comes out of the genus glossina. As soon as the cause of the disease was clearly identified, colonial authorities established extensive control operations, fearing an unpopulated continent and a shortage of human labour to exploit. Terry l dwelle dwelle md mphtm north dakota department. This article is from clinical epidemiology, volume 6.
Sleeping sickness, also known as human african trypanosomiasis hat, is caused by trypanosoma brucei rhodensiense in eastern africa and trypanosoma brucei gambiense in western africa. Clinical features, diagnosis, and treatment of human african trypanosomiasis sleeping sickness. Caused by microscopic parasites of the species trypanosoma brucei. The main reservoir in gambiense trypanosomiasis is infected human beings. Etiology trypanosomes are protozoan parasites in the family trypanosomatidae. Links to pubmed are also available for selected references. It is transmitted to human beings mainly through the. Trypanosomiasis is a worldwide disease caused by the species of the genus trypanosoma, which affects humans, as well as domestic and wild animals.
African trypanosomiasis, also known as african sleeping sickness or simply sleeping sickness. The jos plateau, nigeria was free from tsetse flies and the trypanosomes they transmit due to its high altitude and the absence of animal trypanosomiasis attracted large numbers of cattlekeeping pastoralists to inhabit the plateau. Other routes of transmission are possible but poorly documented and considered extremely rare. The people most exposed to the tsetse fly and therefore the disease are in rural populations dependent on agriculture, fishing, animal husbandry or hunting.
Trypanosoma cruzi, a protozoan hemoflagellate, is the parasite that causes this disease. Human african trypanosomiasis has reemerged as a serious public health threat after nearelimination because of diminished investment in previously successful control programs. Trypanosomiasis accessscience from mcgrawhill education. Sleeping sickness in subsahara n afric a matthew malon e 39201 2 learning goal s understand the causes, risk factors, and modes of transmission for human african trypanosomiasis hat know the role of armed conflict in the rise of infection rates throughout africa. Conference addis ababa, ethiopia, on february 2728, 2010. Full text full text is available as a scanned copy of the original print version.
It depends on the complex interaction of five main factors, viz. Trypanosomiasis article about trypanosomiasis by the. American importance trypanosomiasis iowa state university. A longitudinal survey of african animal trypanosomiasis in. Observations, including infection rates, pcv, temperature and weight loss indicated that the exotic breeds were more susceptible to natural trypanosomal infection than the indigenous breeds and that the infection may be.
Cdc african trypanosomiasis centers for disease control. The human african trypanosomiasis control and surveillance programme of the world health organization 20002009. African trypanosomiasis history and exam bmj best practice. Trypanosomiasis, or sleeping sickness, is the term used to describe a number of diseases affecting vertebrate animals. Control and surveillance of african trypanosomiasis. A combined meeting of the section of comparative medicine royal society of medicine and the royal society of tropical medicine and hygiene was devoted to a discussion of the epidemiology of human and animal trypanosomiasis. American trypanosomiasis chagas disease is an important cause of human heart disease, megaesophagus and megacolon in latin america, where the causative organism, trypanosoma cruzi, is endemic. Human african trypanosomiasis hat, also known as sleeping sickness, is caused by protozoan parasites transmitted via the bite of a tsetse fly. Trypanosomiasis, african sleeping sickness chapter 4. The changing epidemiology of human african trypanosomiasis among patients from nonendemic countries19022012. Epidemiology of human african trypanosomiasis ncbi. Molecular epidemiological studies on animal trypanosomiases in.
Zephyris grants anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law. Epidemiology of human african trypanosomiasis jose r franco, 1 pere p simarro, 1 abdoulaye diarra, 2 and jean g jannin 1 1 world health organization, control of neglected tropical diseases, innovative and intensified disease management, geneva, switzerland. Human african trypanosomiasis world health organization. It has been a serious public health problem in some regions of subsaharan africa. One century ago human african trypanosomiasis hat, also known as sleeping sickness, was believed to curb the development of colonial territories. Since rhodesiense hat is a zoonosis, where the animal reservoir plays a key role, the interruption of the diseases transmission is not deemed feasible. Neuberger a, meltzer e, leshem e, dickstein y, stienlauf s, schwartz e. Carlos chagas first described this disease in 1911 when he discovered the parasite in the blood of a brazilian child with fever, lymphadenopathy, and anemia. Epidemiology of human african trypanosomiasis jose r franco,1 pere p simarro,1 abdoulaye diarra,2 jean g jannin1 1world health organization, control of neglected tropical diseases, innovative and intensified disease management, geneva, switzerland. Parasites african trypanosomiasis also known as sleeping sickness. The standard serologic assay to diagnose west african trypanosomiasis is the card agglutination test for trypanosomiasis catt.
The causative agents of the disease are protozoan parasites of the genus trypanosoma that live and multiply extracellularly in blood and tissue fluids of their mammalian hosts and are transmitted by the bite of infected tsetse flies glossina sp. Human african trypanosomiasis hat, or sleeping sickness, is caused by trypanosoma brucei gambiense, which is a chronic form of the. Human african trypanosomiasis hat, or sleeping sickness, describes not one but two discrete diseases. The other human form of trypanosomiasis, called chagas disease 3. The genus trypanosoma belongs to the family trypanosomatidae, which is in the order kinetoplastida. It is highly sensitive 96% but less specific because of crossreactivity with animal trypanosomes. Human african trypanosomiasis sleeping sickness professor peter ge kennedy glasgow university department of neurology, institute of neurological sciences, southern general hospital, glasgow, uk. African trypanosomiasis is an infectious disease of humans and animals of similar aetiology and epidemiology. Human african trypanosomiasis current treatments and the. Chagas disease, also known as american trypanosomiasis, is caused by infection with the protozoan parasite trypanosoma cruzi. Human african trypanosomiasis hat, or sleeping sickness, is caused by trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central africa, and by trypanosoma brucei rhodesiense, which is an acute disease located in eastern and southern africa. Over the last 100 years huge efforts have been made to control it. The politics of trypanosomiasis control in africa african trypanosomiasis is a devastating disease, both for humans and animals. There are two subspecies of the parasite trypanosoma brucei that cause disease in humans.
It is transmitted by the tsetse fly glossina species, which is found only in rural africa. The human african trypanosomiasis control and surveillance. The release of trypanosome toxic factors and lymphokines gives rise to a cyclic or relapsing fever with an approximate cycle of 710 days. At present, there is no overlap in their geographic distribution. In some countries this may not be legally possible. African animal trypanosomiasis is caused by those organisms that are transmitted by tsetse flies but do not ordinarily affect humans. Prevalence of trypanosoma vivax in cattle in central sudan. African trypanosomiasis, also known as african sleeping sickness or simply sleeping sickness, is an insectborne parasitic disease of humans and other animals. Apart from the presence of vectors, the presence of parasites in reservoirs is needed. A trypanosome is long and pointed and possesses a flagellum. While this organism occasionally causes an acute illness, most people do not realize they are infected until several years or. The file containing the iqc data of the last 3040 plates were sent. The trypanosome is transmitted by different species of tsetse flies, which have differing predilections for breeding sites.
The catt can be conducted in the field without electricity, and results are available in only 10 minutes. Get a printable copy pdf file of the complete article 3. This chapter describes the geographical distribution, vertebrate hosts, triatomine vectors, transmission cycle and disease types of american trypanosomiasis chagas disease. A mathematical model for evaluating the role of trypanocide. And this is mostly restricted to the african continent. This paper explores the scientific and policy debates surrounding the control of the disease and its vector, the tsetse fly. Pdf human african trypanosomiasis hat, or sleeping sickness, is caused by trypanosoma brucei gambiense, which is a chronic form of the disease. Abstract human african trypanosomiasis hat, or sleeping sickness, is caused by trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central africa, and by trypanosoma brucei rhodesiense, which is an acute disease located in eastern and southern africa. Epidemiology of american trypanosomiasis chagas disease. American trypanosomiasis, also known as chagas disease, affects millions of people throughout the americas. The gambian form is currently a major public health problem over vast areas of central and western africa, while the zoonotic, rhodesian form continues to present a serious. The clinical features of the infection depend on the subspecies. This course provides students an understanding of important human parasitic diseases, including their life cycles, vectors of transmission, distribution and epidemiology, pathophysiology and clinical manifestations, treatment, and prevention and control. Control activities are based on active case finding and treatment of detected cases, reducing the reservoir and therefore the transmission of the disease.
The two subspecies are found in different regions of africa. Trypanosomiasis, infectious disease in both humans and animals caused by certain members of the flagellate protozoa genus trypanosoma and spread by certain bloodsucking insects. Trypanosoma cruzi, the cause of american trypanosomiasis, or chagas disease, is a protozoan parasite that is enzootic and endemic in much of the americas, where it infects a wide variety of wild and domestic mammals as well as many species of triatomine vectors, in addition to humans. Modeled burden of human african trypanosomiasis in uganda, under varying integrated control. The epidemiology of trypanosomiasis in rumphi district.
Human african trypanosomiasis hat, or sleeping sickness, is caused by trypanosoma brucei gambiense, which is a chronic form of the disease present in western and central africa, and by. It is caused by protozoa of the species trypanosoma brucei. Epidemiology, control and surveillance of chagas disease. Chagas disease, also known as american trypanosomiasis, is a chronic infection caused by trypanosoma cruzi, a protozoan parasite. Humans are infected by two types, trypanosoma brucei gambiense tbg and trypanosoma brucei rhodesiense tbr.
The causal agents of trypanosomiasis are protozoa belonging to the genus trypanosoma that are transmitted by the bite of a tsetse fly genus glossina or other insects of the triatominae subfamily. Linking to a nonfederal website does not constitute an endorsement by cdc or any of its employees of the sponsors or the information and products presented on the website. Links with this icon indicate that you are leaving the cdc website the centers for disease control and prevention cdc cannot attest to the accuracy of a nonfederal website. Assembling a geospatial database of tsetsetransmitted. The continued, occasional importation of african trypanosomiasis to the united states can be expected as tourists and immigrants travel from highrisk areas. African trypanosomiasis sleeping sickness fact sheet n. African trypanosomiasis sleeping sleepness american. What links here related changes upload file special pages permanent link page. Both protozoan species are morphologically indistinguishable, but have drastically different epidemiological features. Epidemiology the trypanosomes causing hat are classically transmitted by the bite of blood sucking tsetse flies diptera, genus glossina.
The epidemiology and household distribution of seroreactivity to trypanosoma cruzi in a rural community in northeast brazil. We shall look at the vectors, the epidemiology, and control. Trypanosomiasis is a widespread disease of livestock in nigeria and a major constraint to the rural economy. Human african trypanosomiasis exists in two forms with different clinical presentations and epidemiology caused by morphologically indistinguishable subspecies of t brucei fig fig3. African trypanosomiasis known as african sleeping sickness endemic in 36 countries and affects from 20,000 to 50,000 annually untreated is universally fatal animal infections may have more impact than human infections by decreasing the. The epidemiology of sleeping sickness is com plex and transmission. Epidemiology and control of human african trypanosomiasis. The clinical features of the infection depend on the subspecies involved. The rhodesiense form is a zoonosis, with the occasional infection. Caemichael pointed out that the mammalian trypanosomes could be divided into 2 groups. Thus, we assume that flies that have not been infected during their first blood meal are no.
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