Infection Sleeping sickness is transmitted between animals and man and between humans by the tse tse fly. Wild animals like buffaloes are natural hosts to the parasite. After the tse tse fly has been infected the parasite develops for about 3 weeks before the infection can be transmitted to a new host.
Symptoms The incubation period is 2 to 3 weeks and the main symptom in the beginning is fever. A faint rash is sometimes seen around the place of the tse tse bite and local lymph nodes may be swollen.
If the disease is not treated at this stage when the parasite is found in the blood alone, the parasite may invade the brain and cause encephalitis with lethargy, which has given the disease its name as the patient appear to be sleeping. In addition there is headache and seizures.
Diagnosis The parasites can be found in the blood by microscopy as malaria parasites. Alternatively antibodies can be found in a blood sample. If the parasites have reached the brain they can be found in a spinal tap sample.
Treatment A few antibiotics are available for treatment of the blood infection, but treatment of the brain infection is difficult.
Prevention Avoid bites by tse tse flies. Tse tse flies bites only during daytime and of particular risk are visitors to game parks.
More about Sleeping sickness is found from The Gambia in west Africa to Botswana in southern Africa.
Recent emergence of sleeping sickness in Central and East Africa Most probable due to the wars in Central Africa and southern Sudan over the past decades sleeping sickness for instance in the Democratic Republic of Congo, DRC, is as prevalent now as when statis-tics were first collected in 1925.
At least 8 tourists visiting game parks in western Tanzania especially Serengeti have been diagnosed with sleeping sickness in 2000 and 2001 after returning back home, and two more were reported in 2008.