African trypanosomiasis risk factors

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2]

Risk factors for African trypanosomiasis include residence in Central or South America, living in old houses with mud and stick wall constructions or straw roofs, ingestion of contaminated water, or receiving blood transfusions or organ donation from individuals in regions with high endemicity. The risk of infection increases with the number of times a person is bitten by the tsetse fly. The neonatal risk is highest among those who breastfeed from bleeding or cracked nipples of infected mothers and infants who are delivered from seropositive mothers with active disease.

Common risk factors in the development of African trypanosomiasis include:^[1]

• Living in Central or South America
• Residing in a house constructed before the year 2000
• Exposure to either wall constructions composed of mud and sticks or straw roofs
• Ingestion of contaminated water
• Living in a hut where reduvid bugs live in the walls
• Poverty
• Receiving either a blood transfusion or an organ transplant from a person in regions with high endemicity
• Maternal seropositivity and exacerbation of infection during pregnancy
• Bleeding/cracked nipples of infected mother during breastfeeding
• Immunosuppression

In addition to the bite of the tsetse fly, the disease is contractible in the following ways:

• Vertical transmission:
  • The trypanosome can cross the placenta and infect the fetus, causing perinatal death
• Laboratories:
  • Accidental infections (for example, through the handling of blood of an infected person or organ transplantation, although this is uncommon)
• Blood transfusion