Trypanosomiasis

Human African Trypanosomiasis is a parasitic vector-borne disease transmitted from animals to humans by flies. There are 2 forms of the disease, both found in Africa. One form is found in West and Central Africa and the other in Eastern and Southern Africa. They are commonly known as West African Sleeping Sickness and East Africa Sleeping Sickness.

Domestic and wild animals are the reservoirs for disease. Both forms are transmitted by Tsetse flies. They bite during daylight hours. Only a very small proportion of flies are infected. The disease can also be transmitted through blood, and rarely to foetuses during pregnancy.

African Trypanosomiasis is rare with fewer than 100 cases of East African Trypanosomiasis and less than 600 cases of West African Trypanosomiasis reported to the WHO in 2020. Control methods have reduced the number of cases by over 97% in the last 20 years.

Most of the reported cases are in the Democratic Republic of the Congo (> 60%).

• 10-100 cases: Angola, Central African Republic, Chad, Congo, Gabon, Guinea, Malawi, South Sudan.
• 1-10 cases: Cameroon, Cote d’Ivoire, Equatorial Guinea, Uganda, Tanzania, Ethiopia, Zambia.
• Occasional: Burkina Faso, Ghana, Kenya, Nigeria, Zimbabwe.
• Nil reports: Benin, Botswana, Burundi, Eswatini, Gambia, Guinea Bissau, Liberia, Mali, Mozambique, Namibia, Niger, Rwanda, Senegal, Sierra Leone, Togo.

The disease is generally fatal if left untreated.

The disease is very rare in travellers.

It is more likely in hunters and those involved with animal husbandry.

In a study of cases identified in non-endemic countries, just 49 cases were identified over 10 years. Thirty-five cases involved tourists visiting wildlife parks in East and Southern Africa and 14 involved migrants returning from endemic areas of Western and Central Africa.

Disease prevention rests with insect avoidance.

Insect repellents and permethrin use has not been shown to be as effective as with other insects, such as mosquitos.

Chagas disease is a parasitic vector-borne disease transmitted to humans by a bug. It can also be transmitted by blood and blood products as well as mothers to unborn foetuses. An estimated 6-7 million people are infected with the parasite. Endemic areas include Mexico and Central and South America.

The bugs (kissing bugs) typically live in the wall or roofs of homes or attached structures. The bugs hide during the day and come out at night for blood feed. The parasite is transmitted to the individual after the bug defecates near the bite and scratching pushes the parasite into the wound.

It is estimated to cause 20,000 deaths annually.

The disease is very rare in travellers.

Travellers may be at increased risk if they stay in poor quality housing (thatch, mud or adobe) in endemic areas. Transmission can also occur through contaminated food, which is the most likely source of an outbreak.

It is more a disease of migrants from endemic areas than travellers.