Trypanosoma Health Dictionary

There are two major forms of the disease: Trypanosoma brucei gambiense is con?ned to west and central Africa, and T.b. rhodesiense to central, east, and south-east Africa. The infection is caused by the bite of tsetse ?y (Glossina spp.). Clinically, a trypanosomal CHANCRE may develop at the site of the tsetse-?y bite. After introduction into the bloodstream, the parasite develops in blood and lymphatic glands. After the blood stage, it enters the central nervous system, causing characteristic neurological sequelae (see below). Infection may be followed by a generalised macular papular reaction. In

T.b. gambiense infection, enlarged glands in the neck (Winterbottom’s sign) may be striking. Onset of disease is accompanied by fever, progressive ANAEMIA, and enlarged glands; these signs and symptoms are followed by increasing lethargy, slowing of mentality, and physical weakness, and give way to headache and an increasing tendency to sleep. These symptoms are caused by proliferation of parasites in the patient’s cerebral blood vessels; this is accompanied by in?ammatory changes and disorganisation of nervous tissue. Patients become emaciated and develop bed sores. Death ?nally takes place either as a result of gross emaciation or of an intercurrent infection.

Diagnosis is by detection of trypanosomes in a blood specimen or, alternatively, a sample of cerebrospinal ?uid. Serological tests are of great value in diagnosis.

Treatment is with suramine or pentamidine; when cerebral involvement has ensued, melarsoprol – which penetrates the blood-brain barrier – is of value. In T.b. gambiense infection, e?ornithine has recently given encouraging results; however, this form of CHEMOTHERAPY is not e?ective in a T.b. rhodesiense infection. From the point of view of prevention, control of the tsetse-?y population is crucial; even so, only a very small percentage of these vectors is infected with Trypanosoma spp.... sleeping sickness

A disease caused by parasites of the genus Trypanosoma and including sleeping sickness in Africa and Chagas disease in Central and South America.... trypanosomiasis

Chagas’ disease, or American trypanosomiasis, is a disease widespread in Central and South America, and caused by the Trypanosoma cruzi. The disease is transmitted by the biting bugs, Panstrongylus megistus and Triatoma infestans. It occurs in an acute and a chronic form. The former, which is most common in children, practically always affects the heart, and the prognosis is poor. The chronic form is commonest in adolescents and young adults and the outcome depends upon the extent to which the heart is involved. There is no e?ective drug treatment. (See also SLEEPING SICKNESS.)... chagas’ disease

Blood sucking hemipterans found in Latin America and which serve as vectors for Trypanosoma cruzi, the cause of Chagas’ Disease. These insects are also known as ‘cone nose bugs’, ‘assassin bugs’ or ‘triatomids’. They belong to the family Reduviidae and the genera Rhodnius and Triatoma, Panstrongylus amongst others.... reduviid bugs

A posterior cervical lymphadenopathy indicative of early West African (Gambian) Sleeping Sickness due to Trypanosoma brucei gambiense.... winterbottom’s sign

n. a type of *protozoan with one or more fine whiplike threads (see flagellum) projecting from its body surface, by means of which it is able to swim. Some flagellates are parasites of humans and are therefore of medical importance. See Trypanosoma; Leishmania; Giardia; Trichomonas.... flagellate

pl. n. a group of microscopic single-celled organisms. Most protozoa are free-living but some are important disease-causing parasites of humans; for example, *Plasmodium, *Leishmania, and *Trypanosoma cause *malaria, *kala-azar, and *sleeping sickness respectively. See also amoeba.... protozoa

n. a large bloodsucking fly of tropical Africa belonging to the genus Glossina. Tsetse flies, which have slender forwardly projecting biting mouthparts, feed during the day on humans and other mammals. They transmit the blood parasites that cause *sleeping sickness. G. palpalis and G. tachinoides, which are found along river banks, transmit Trypanosoma gambiense; G. morsitans, G. swynnertoni, and G. pallidipes, which are found in savannah country, transmit T. rhodesiense.... tsetse