Trypanosomiasis (Sleeping sickness)

The parasite
There are 2 identical parasites which cause similar but not identical disseases.
Trypanosoma brucei gambiense and rhodesiense occur in Subsaharan Africa.
Trypanosoma cruzi is the cause of the American form.

Distribution
The African form of infection is only found in Africa south of the Sahara and north of the Zambesi river.
The South American form (Chagas Disease) is found in South America and central America as far north as Mexico.

Transmission
Both infections are spread through the bite of an infected tsetse fly (African) and reduviid 'bugs' (American).

The African illness: The bite itself can cause considerable pain and if caused by an infected fly developes after 5 or more days into a chancre. This resembles a boil but without containing pus. The first symptoms are usually fever and then lymphadenapathy, often behind the neck. This can last several months and may resolve spontaneously but, especially if due to T.br.rhodesiense, can then develop into severe neurological illnes with CNS invasion and death. sometimes the disease is more rapid. The terminal stage frequently causes changes in behaviour and sleep disturbance - eventually coma (hence the name sleeping sickness)
Treatment: This involves potentially toxic drugs such as suramin and melarsoprol and should supervised by a specialist.

The American illnes: facial oedema, toxaemia, lymphadenopathy with enlaged liver and spleen are early findings which can be followed by cardiac and meningo-encephalitis. Chronic disease many years later can present with cardiomegaly, mega-oeophagus and megacolon.
Treatment: Nifurtimox can help in the early stages but drugs are not normally helpful in chronic disease.

Prevention is through avoiding tsetse fly bites and bug bites.

Recommended for more information: 'Lecture Notes in Tropical medicine'. Dion R. Bell. Blackwell Publications ISBN 0-632-02445-0 or 'Mansons textbook of Tropical Diseases' Ed.G.C.Cook WB Sanuders Company Ltd ISBN 0-7020-1764-7.