Sleeping sickness, also called African trypanosomiasis, is a swelling of the brain caused by parasites that live in infected tsetse flies. When a tsetse fly infected the parasite bites a human being, the parasite is passed into the person's blood stream. In addition, an infected mother can pass the illness on to her to unborn child. Symptoms include insomnia, swollen lymph nodes, sweating, and coma. Left untreated, African trypanosomiasis can result in death.
Two types of parasites can cause sleeping sickness. One is Trypanosoma brucei rhodiense, or T. brucei rhodiense, which results in a more rapidly developing form of African trypanosomiasis. The second is Trypanosoma brucei gambiense, or T. brucei gambiense.
African trypanosomiasis typically occurs in rural areas that have poor medical facilities. These areas may be close to rivers, lakes, or woods. Trypanosoma brucei gambiense, the parasite that is responsible for about 90 percent of all sleeping sickness cases, live in tsetse flies in west and central Africa. T. brucei rhodiense infect tsetse flies, and eventually people, in eastern and southern Africa.
When an infected tsetse fly bites a person, the bite can be painful and cause swelling. The parasite moves into the bloodstream and reproduces, resulting in early symptoms such as sweating, fever, and headaches. After invading the bloodstream, the parasite moves into the central nervous system. It becomes more difficult to cure sleeping sickness when the infection has progressed to this stage.
Sleeping sickness caused by T. brucei gamiense develops over a longer period of time than sleeping sickness caused by T. brucei rhodiense. Those who have been bitten by a fly infected by T. brucei gamiense may take months or even years to exhibit symptoms. In fact, by the time this type of sleeping sickness is diagnosed, the infection may have already passed into the central nervous system. T. brucei rhodiense sleeping sickness develops more quickly and can affect the central nervous system within weeks.
Treatments for African trypanosomiasis depend on the stage at which the infection is diagnosed. Before the infection has spread to the central nervous system, African trypanosomiasis caused by T. brucei gamiense can be treated with pentamidine injections and suramin can be used to treat infections caused by T. brucei rhodiense. At later stages, a form of arsenic, melarsopro, is used to treat both types of sleeping sickness. Another drug called eflornithine, which has fewer of the severe side effects of melarsopro, can be used to treat African trypanosomiasis caused by Trypanosoma brucei gambiense when the disease is more advanced.