Sarcocystis neurona, seroprevalence of antibodies in equines and research of oocystis in opossum in Ilhéus – Itabuna microregion, Bahia, Brazil.

This research reveals that in the region of Ilhéus-Itabuna, Brazil, around 7.92% of sampled horses had antibodies relating to Sarcocystis neurona, an organism causing disease in these animals. Sporocysts/oocysts associated with this parasite were also investigated in local opossum populations (Didelphis spp.), but they proved negative. Meanwhile, the study identified work and trade uses for horses as significant factors related to the presence of S. neurona antibodies.

Objectives and Methodology

• The research primarily sought to determine the seroprevalence of Sarcocystis neurona antibodies among horses in the Ilhéus-Itabuna region of Brazil. It also sought to determine associated risk factors.
• The study also aimed to verify the presence of sporocysts/oocysts related to Sarcocystis spp. in local Didelphis spp. (opossum) populations.
• The researchers collected a total of 669 serum samples from horses across 56 properties located in 12 municipalities in the region.
• An indirect fluorescent antibody test was performed to identify the merozoites of the S. neurona, using a cut-off titer of 1:80.

Findings

• The study found 7.92% prevalence of anti-S. neurona antibodies in the sampled horses.
• Researchers identified two significant factors associated with antibodies presence: trade and work uses for horses.
• 21.6% of horses used for work purposes were noted as a risk factor for S. neurona infection, whereas horses used for trade, coming in at 3.6%, were deemed a protective factor.

Investigation on Opossums

• 25 Didelphis spp. (opossum) were captured for inspections on sporocysts/oocysts in stool samples and intestinal scrapings.
• All tested samples from Didelphis spp. were negative for the presence of Sarcocystis spp.
• Despite the negative result in opossums, the study asserts the seroprevalence of S. neurona observed in horses in this area of southern Bahia, Brazil, suggesting another source of infection.