African Trypanosomiasis (Sleeping Sickness): Travel Health Guide

What is African trypanosomiasis?

The infection is caused by two subspecies of the parasite Trypanosoma brucei. Both are transmitted by tsetse flies, but their geographic distributions and typical disease progression differ.

West and Central African sleeping sickness

Trypanosoma brucei gambiense causes a generally slower-developing infection. Symptoms may emerge gradually over months or even years. The disease occurs in localized areas of West and Central Africa, with humans serving as an important reservoir of infection.

East and Southern African sleeping sickness

Trypanosoma brucei rhodesiense causes a more rapidly progressive infection, sometimes becoming severe within weeks. Wild animals and livestock are important reservoirs. Travelers visiting certain wildlife areas, game reserves, and rural environments may encounter infected tsetse flies.

Despite their names, the two forms do not divide Africa into uniformly affected western and eastern halves. Their distribution is localized and changes over time. African trypanosomiasis is also distinct from American trypanosomiasis, or Chagas disease, which occurs mainly in Latin America and involves a different parasite and insect vector. See the US Centers for Disease Control and Prevention (CDC) disease overview.

Where does it occur, and who is at risk?

Human African trypanosomiasis is geographically restricted to sub-Saharan Africa. WHO identifies the gambiense form as endemic in 24 countries in West and Central Africa and the rhodesiense form in 13 countries in East and Southern Africa. However, transmission is often concentrated in relatively small areas, and many places where tsetse flies occur have little or no documented human transmission.

According to WHO's Global Health Observatory, 430 gambiense cases and 41 rhodesiense cases were reported worldwide in 2025. These figures reflect major long-term reductions in reported disease, not the complete disappearance of transmission.

Travel exposures that can matter include:

• Wildlife safaris and game reserves: Spending time in vegetation or wildlife habitats in affected parts of eastern and southern Africa.
• Rural work and extended stays: Farming, livestock activities, conservation, field research, hunting, and work in isolated communities.
• Outdoor activities: Walking through dense vegetation, particularly in areas known to contain tsetse flies.
• Urban visits: Generally much lower risk than travel to affected rural environments.

Historically affected countries and national parks should not automatically be considered active transmission areas today. Travelers should seek destination-specific information about their actual route, including individual reserves or districts, rather than relying solely on country-level disease lists.

Prevention and preparation

Preventing tsetse fly bites is the principal protective measure. Tsetse flies are active during daylight hours, can bite through lightweight fabrics, and may be attracted to moving vehicles. Unlike mosquitoes, they are not reliably deterred by standard insect repellents.

The CDC's sleeping sickness prevention guidance recommends several practical precautions:

• Wear medium-weight, long-sleeved shirts, long pants, and socks when entering potential tsetse habitats.
• Choose neutral-colored clothing rather than bright colors or very dark shades, particularly blue and black.
• Inspect vehicles for flies before entering and remove any flies that have entered.
• Avoid unnecessary contact with dense bushes and vegetation, especially when flies may be resting there.
• Ask knowledgeable local guides or residents about areas with frequent tsetse fly activity.

Insect repellents and permethrin-treated clothing remain useful against other biting insects, but should not be relied upon as the main defense against tsetse flies. The CDC Yellow Book's guidance on mosquitoes, ticks, and other arthropods provides additional information about insect-bite prevention.

Vaccination and preventive medication

There is no vaccine or preventive medication for human African trypanosomiasis. Travelers cannot prevent this infection by taking antimalarial drugs or receiving vaccinations for other travel-related diseases.

Other vaccines and malaria prevention measures may still be appropriate for the destination. These should be assessed separately according to the itinerary, entry requirements, individual health circumstances, and current destination guidance.

Symptoms and when to seek medical attention

Early symptoms may resemble other infections and can include fever, headache, fatigue, muscle or joint pain, swollen lymph nodes, and sometimes a painful or inflamed sore at the bite site. Not everyone develops a noticeable bite lesion.

As the disease progresses, parasites may enter the central nervous system. Symptoms can include changes in sleep patterns, behavioral or personality changes, confusion, difficulty coordinating movements, and other neurological problems. Severe disease can lead to coma and death.

Seek prompt professional assessment

Anyone who develops an unexplained fever or compatible symptoms after visiting an area with possible tsetse fly transmission should seek medical evaluation promptly and describe their travel history. This is particularly urgent following potential exposure in eastern or southern Africa, where rhodesiense infection can progress rapidly.

Confusion, seizures, significant neurological changes, reduced consciousness, or rapidly worsening illness require emergency medical assessment. Do not wait for the characteristic sleep disturbances to appear.

Symptoms may begin after a traveler has returned home. Gambiense infection can remain unrecognized for a prolonged period, making details of earlier rural travel relevant even months or years afterward. See the CDC guidance on symptoms, exposure, and seeking care.

Diagnosis and treatment

Diagnosis requires specialized testing to identify the parasite or otherwise investigate suspected infection. Clinicians may examine blood or other samples, and assessment of the central nervous system may be necessary to determine disease stage.

Human African trypanosomiasis is treatable, but treatment must be selected according to the parasite involved, the stage of infection, and individual clinical circumstances. Hospital-based care and specialist expertise are commonly required.

Because the disease is uncommon in many countries, a returning traveler may need referral to an infectious disease or tropical medicine specialist. Treatment should not be delayed when infection is strongly suspected. WHO provides an overview of the diagnostic and treatment considerations for human African trypanosomiasis.

Special considerations for travelers

Children and pregnancy

Children and pregnant travelers should follow the same fundamental tsetse avoidance precautions, with clothing and insect-repellent products appropriate to their circumstances. CDC notes that infection can occasionally pass from a pregnant woman to her unborn baby. Suspected infection during pregnancy requires prompt specialist assessment because clinical management must consider both maternal and fetal health.

Remote travel and medical access

Diagnosis and treatment may not be readily available in remote areas. Travelers undertaking extended rural work, safaris, or expeditions should identify suitable medical facilities and evacuation arrangements before departure. Insurance coverage for medical evacuation is particularly relevant where access to specialized care is limited.

After returning home

A tsetse fly bite does not necessarily mean infection. Most flies are not carrying the parasite, and routine screening of asymptomatic travelers is generally not recommended. However, unexplained fever or compatible neurological symptoms following a relevant exposure warrant assessment, even if the trip occurred some time earlier.

Keep a record of visited countries, parks, rural districts, travel dates, and any notable insect exposure. These details can help clinicians evaluate an illness that is rarely encountered outside endemic areas.

Key points for travelers

African trypanosomiasis is an uncommon but serious travel-related infection with a highly localized distribution. Risk is greatest where relevant tsetse fly populations and parasite transmission overlap, especially during certain rural and wildlife-related activities. There is no vaccine or preventive medication, so avoiding bites and obtaining timely medical attention for suspicious symptoms are essential.

This information is intended for general travel-health education and does not replace individualized advice, diagnosis, or treatment from a qualified healthcare professional.