Seroepidemiology and molecular detection of Brucella infection in Iranian horses: Aprovincial study

BACKGROUND: Brucellosis is a febrile zoonotic infectionand has worldwide distribution among humans as well asanimals. Although the seroprevalence of brucellosis in variousanimals has been described in Iran, there is only one report onequine brucellosis in the region. OBJECTIVES: This study wascarried out to determine the seroprevalence of brucellosis inracing clubs and private horse owners in the south of Iran and riskfactors associated with the disease in horses. METHODS: 312randomly selected equine serum samples were investigated forthe presence of antibodies against Brucella genus, using slideagglutination by Rose Bengal plate test (RBPT), serum agglutinationtest (SAT) and 2-mercaptoethanol (2-ME) test, usingwhole cell antigen. PCR assay was also used for detection ofclinically suspected cases. RESULTS: Most seropositive horsesin this study were asymptomatic. The true seroprevalence ofbrucellosis was found to be 9.9, 8 and 7% by RBPT, SAT and 2-mercaptoethanol tests, respectively. All horses with history ofclinical signs (3.2% of all samples) had RBPT, SAT and 2-mercaptoethanol positive results. It was also revealed that age,sex and a history of contact with ruminants had no effect onacquiring the infection in positive cases. In the PCR, one of thethree horses with fistula withers produced amplicon of 450 bpfragment of wbo sequences specific to Brucella spp. field strain.CONCLUSIONS: This study showed the seroprevalence ofbrucellosis in horses of Fars province and it was indicated thatthe PCR assay may be helpful in detection of clinically suspectedhorses.