Although only a couple of cases of US travelers get this disease annually, many tourists choose the adventure of game parks in Africa to spend their vacation.
Often a fatal disease with 15,000-20,000 cases reported annually, more than 60 million people are at risk in more than 30 African countries.
One of the true tropical diseases, African sleeping sickness is endemic only in sub-Sahara Africa bounded by 15° North and South latitudes.
Two varieties of African sleeping sickness exist: one primarily in East Africa caused by the parasite Trypanosoma brucei rhodesiense. T.B. rhodesiense produces an acute infection that will usually cause severe illness and death in weeks to months.
The other species is Trypanosoma brucei gambiense. This parasite is found in West and Central Africa. However, the 2 species are showing some geographic overlap.
This infection progresses more slowly and may require months to years for disease to occur.
Both types of sleeping sickness are caused by the bite of a tse tse fly. These vicious little bugs depend on blood meals for its nutrients. It gets the blood from mammals including humans. The tse tse fly (below) has a very painful bite and a traveler will certainly remember getting bit.
When taking a blood meal, the fly injects the parasite into the skin. From here the parasite is carried to the lymphatic system and eventually the bloodstream.
They go through stages in the body and eventually end up in the spinal fluid.
Symptoms are as follows:
• East African sleeping sickness: the development of a chancre at the bite site followed by fever, fatigue, aching muscles and joints and swollen lymph nodes are characteristic. After central nervous system (CNS) invasion neurological manifestations may occur followed by death if untreated.
• West African sleeping sickness: symptoms are similar to the above however taking longer to appear. Progressive confusion, personality changes, daytime sleepiness with nighttime sleep disturbances are late stage symptoms. Death will happen after several years if left untreated.
There is no immunity produced so reinfection is possible.
Diagnosis of African sleeping sickness is based on finding the parasite in blood (below), spinal fluid or lymph node aspirates.
There are treatment options for sleeping sickness depending on blood stage or CNS stage. Treatment should begin as soon as possible.
There is no vaccine for African trypanosomes. The Centers for Disease Control and Prevention recommends the following preventive measures:
1. Wear protective clothing, including long-sleeved shirts and pants. The tsetse fly can bite through thin fabrics, so clothing should be made of medium-weight material.
2. Wear neutral-colored clothing. The tsetse fly is attracted to bright colors and very dark colors.
3. Inspect vehicles for tsetse flies before entering. The tsetse fly is attracted to moving vehicles.
4. Avoid bushes. The tsetse fly is less active during the hottest period of the day. It rests in bushes but will bite if disturbed.
5. Use insect repellant. Though insect repellants have not proven effective in preventing tsetse fly bites, they are effective in preventing other insects from biting and causing illness.
Areas of heavy infestation tend to be sporadically distributed and are usually well known to local residents. Avoidance of such areas is the best means of protection.