The use of enzyme linked immunosorbent assays to investigate the prevalence of Trypanosoma equiperdum in Ethiopian horses.

The research study used a specific lab method to detect the presence of a parasite (Trypanosoma equiperdum) which causes a sexually transmitted disease in horses, in an area of Ethiopia, and suggests that the prevalence of this disease might be far more widespread than previously realized.

Study Background

• The study examined the prevalence of Trypanosoma equiperdum, a parasite that causes dourine, a venereal disease in horses, in the highlands of Ethiopia.
• The researchers employed the use of enzyme linked immunosorbent assays (ELISAs), a lab technique that measures the presence of an antibody or an antigen (substance that induces an immune response in the body).

Methodology

• A total of 309 horses of different ages and sexes from the provinces of Arsi and Bale were examined for infection signs, and their blood samples collected for assay.
• These samples were then tested for the presence of a particular parasite antigen (a protein that triggers immune response) and antibodies (the immune response) against the parasite.
• Horses positive for the infection, as indicated by presence of the parasite antigen and antibodies, were observed for clinical signs of dourine.
• The researchers also attempted to isolate the parasites by inoculating blood and genital washes from seropositive horses into mice and rabbits.

Results and Conclusions

• The ELISA tests detected trypanosomal antibodies in 101 horses and pathogenic antigens in 19 horses.
• A direct correlation between the presence of the parasite antigen and observed clinical signs of infection in horses was found.
• Statistical analysis demonstrated a significant difference in the distribution of seropositive horses across different clinical groupings, with an increase in seropositivity corresponding to the severity of the clinical signs.
• Despite the researchers being unable to directly isolate the parasite, the observations and results provided strong indirect evidence of the occurrence of T. equiperdum in the regions under study.
• The study suggests that the disease may be far more widespread in Ethiopia than previously thought, given the unrestricted movement of horses throughout the country.
• The researchers conclude that the ELISA assays show promise for diagnosing the disease but must be validated for their accuracy before widespread application in Africa.