Thursday, September 8, 2011

African Trypanosomiasis (African Sleeping Sickness)

What is African trypanosomiasis (African sleeping sickness)?

African trypanosomiasis, also called African sleeping sickness, is a systemic disease caused by a parasite and transmitted by the bite of the tsetse fly. There are two types of the disease, named for the areas of Africa in which they are found. West African trypanosomiasis, which causes a chronic infection lasting years, is caused by the parasite Trypanosoma brucei gambiense. East African trypanosomiasis, which causes acute illness lasting several weeks, is caused by Trypanosoma brucei rhodesiense. Infection of international travelers is quite rare, with an average of one case in a U.S. citizen per year.   

African trypanosomiasis is confined mainly to tropical Africa between 15 degrees North and 20 degrees South latitude. The greatest risks of contracting the disease occurs in parts of Eastern, Southeastern, and Central, and limited areas of West Africa, including:

• Angola 

• Central African Republic

• Chad

• Congo

• Democratic Republic of Congo

• Malawi

• Tanzania 

• Sudan

• Uganda 

• Zambia

Because tsetse flies inhabit rural areas only, living in woodland thickets of the savanna and dense vegetation along streams, visitors to urban areas are generally not at risk.

What are the symptoms of African trypanosomiasis?

The following are the most common symptoms of African trypanosomiasis. However, each individual may experience symptoms differently.

Symptoms, which occur within one to four weeks of infection, are often initially nonspecific and may include fever, skin lesions, rash, edema, or swollen lymph nodes on the back of the neck. After many weeks, the infection then generally progresses to meningoencephalitis, which is infection of the fluid surrounding the brain and spinal cord. As the illness progresses, symptoms may include:

• Severe headache

• Personality change

• Weight loss

• Irritability

• Loss of concentration

• Progressive confusion

• Slurred speech

• Seizures

• Difficulty walking and talking

• Sleeping for long periods of the day

• Insomnia at night

If left untreated, death will occur within several weeks to months. The symptoms of African trypanosomiasis may resemble other medical conditions or problems. Always consult a physician for a diagnosis.

How can African trypanosomiasis be prevented?

There is no vaccine or recommended drug available to prevent African trypanosomiasis. Therefore, preventive measures should be aimed at avoiding insect bites. The Centers for Disease Control and Prevention (CDC) recommends the following:

• Wear protective clothing, such as long-sleeved shirts and pants. Tsetse flies can bite through material, so clothing should be made of thick material.

• Wear khaki, olive, or other neutral-colored clothing. Tsetse flies are attracted to bright and dark contrasting colors.

• Use insect repellant. While insect repellants are not effective in preventing bites by the tsetse fly, they can prevent other insect bites and illnesses.

• Use bednets when sleeping.

• Inspect vehicles for tsetse flies before getting into them.

• Avoid riding in the back of jeeps, pickup trucks, or other open vehicles. Tsetse flies are attracted to the dust created by moving vehicles and animals.

• Avoid bushes. During the hottest part of the day, the tsetse fly will rest in bushes, but will bite if disturbed.

How is African trypanosomiasis diagnosed?

See a physician as soon as possible if you suspect an infection. He/she will order several tests to detect the parasite. Common tests include blood samples and a spinal tap. A sample of chancre fluid or tissue, or fluid from swollen lymph nodes may also be taken.

Treatment for African trypanosomiasis

Specific treatment for African trypanosomiasis will be determined by your physician based on:

• Your age, overall health, and medical history

• Extent of the disease

• Your intolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

Medication for the treatment of African trypanosomiasis is available. Hospitalization is necessary and periodic follow-up exams, which include a spinal tap, are generally necessary for about two years. Because this infection is so rare, physicians are recommended to consult with an infectious disease or tropical medicine specialist for diagnosis and treatment. Physicians can also consult with CDC for assistance with diagnosis and clinical management.