The capybara (Hydrochoerus hydrochaeris) as a reservoir host for Trypanosoma evansi.

This research article investigates the capybara (a large rodent native to South America) as a potential host for the parasite Trypanosoma evansi, which was discovered in ill horses and dogs in Colombia. The study concludes that capybaras can indeed act as reservoir hosts for this parasite.

Research Context

• The research began after the discovery of two horses and three dogs infected with Trypanosoma evansi, a parasite responsible for causing serious diseases in animals.
• This finding spurred investigation into potential reservoir hosts of the parasite, focusing on the Eastern Plains of Colombia.

Experiments and Findings

• Different animals were tested for infection: 33 capybaras, 14 horses, 32 Zebu cattle, 18 paca, and 20 spiny rats. Infection was detected only in capybaras – 8 out of 33 showed signs of infection.
• The absence of infection in the remaining animals tested disproved common assumptions about the host range of Trypanosoma evansi.
• The evidence of infection in healthy capybara contradicts earlier beliefs that capybara were not susceptible.

Diagnostic Methods

• The detection and diagnosis of Trypanosoma evansi in the animals were based on multiple factors:
• Morphology: Examination of the physical characteristics and structure of the organisms involved.
• Behaviour in albino rats: The reactions and effects of the parasite in albino rats were observed.
• Pathogenicity and host range in domestic animals: The ability of the parasite to cause disease, and the range of animals it could infect, were explored.

Conclusion and Implications

• The study concluded that capybara can indeed function as a carrier for Trypanosoma evansi, contrary to prior beliefs.
• This discovery has implications for disease management and prevention in regions where both capybaras and this parasite coexist.