Seroprevalences of anti-Sarcocystis neurona and anti-Neospora hughesi antibodies among healthy equids in the United States.

This research article provides an analysis of the presence of certain antibodies against Sarcocystis neurona and Neospora hughesi in healthy horses throughout the United States. The goal was to determine the potential risk factors for positive tests against these antibodies.

Design and Sample

• This research is built on a cross-sectional study design, where blood samples were collected from a total of 5,250 horses (each horse providing one sample) in 18 states across the U.S. during October 2013.
• Potential risk factors such as geographic region, breed, primary usage, gender, and the age of the horses were also recorded along with blood collection.
• Each horse’s blood sample then underwent an indirect fluorescent antibody test to identify serum titers of the antibodies against the Sarcocystis neurona and Neospora hughesi protozoan parasites.

Procedure and Results

• Mixed-effects logistic regression models were prepared to establish the odds ratios for proving seropositivity.
• Results showed that overall seroprevalence of anti-Sarcocystis neurona and anti-Neospora hughesi antibodies was noted at 78% and 34%, respectively, in the tested horses.
• The data revealed that 31%of horses were seropositive while 18% were seronegative for antibodies against both parasites.
• Key factors that contributed to horses being seropositive for anti-Sarcocystis neurona antibodies included residence in the southern states, belonging to the warmblood breed, and an age older than 5 years.

Conclusions and Clinical Relevance

• Regarding the overall risk factors for Sarcocystis neurona and Neospora hughesi exposure and antibody response among the tested horses, it wasn’t surprising that older age was a contributing factor.
• However, the influences of the warmblood breed and residing in the southern geographic region on seropositivity for anti-Sarcocystis neurona antibody – but not for anti-Neospora hughesi – could provide new areas for further research and investigation.