Seroprevalence and Factors Associated with Toxoplasma gondii Infections in Sheep in Latvia: Latvian Dark Headed Sheep Breed Associated with Higher Seroprevalence.

Toxoplasma gondii is a protozoan parasite with both public health and veterinary importance. The aims of our study were to estimate the T. gondii seroprevalence in sheep in Latvia and to evaluate potential risk factors for seropositivity. The blood samples investigated were collected from 1039 sheep from 84 farms between January 2012 and April 2013. The sera were tested for immunoglobulin G antibodies against T. gondii using an in-house enzyme-linked immunosorbent assay. Antibodies against T. gondii were detected in 179 (17.2%) of the sheep, and at least one seropositive sheep was found on 37 (44.0%) of the farms. The seroprevalence was significantly higher in adult (over 1 year old) sheep than in juveniles-the adult sheep had 1.8 times higher odds to test seropositive than did the juveniles. The seroprevalence was significantly higher in Latvian Dark Headed sheep than in crossbreed and German Merino sheep. Sheep from large herds (with more than 100 sheep), as well as those from farms with cattle, had higher odds to test seropositive, whereas the presence of poultry on the farm appeared as a protecting factor. The results show that sheep in Latvia are commonly exposed to T. gondii.