Seroprevalence of Specific Antibodies to Toxoplasma gondii, Neospora caninum, and Brucella spp. in Sheep and Goats in Egypt

SIMPLE SUMMARY: Toxoplasma gondii, Neospora caninum and Brucella species are widely distributed infectious agents that induce severe clinical illness in numerous farm animals. In addition T. gondii and Brucella spp. are of public health concern because of their zoonotic potentials. In Egypt and other countries, toxoplasmosis, neosporosis, and brucellosis are three well-known etiological agents of infectious abortion in many farm animals including sheep and goats. Inaccurate diagnosis of the abortion cause results in great economic losses because of application of inappropriate control measures. In the current study, we provided the first report on the comparative seroprevalence of toxoplasmosis, neosporosis and brucellosis in sheep and goats in Egypt based on antibody detection. We found that the overall seroprevalence rate was the highest for T. gondii. Nevertheless, only antibodies to Brucella spp. were associated with recent abortion in sheep and goats. Our study provides solid data on the existence of abortifacient agents in the common small ruminants in Egypt. Accordingly, these data can be exploited in developing more efficient control policies against such serious infections. ABSTRACT: Toxoplasmosis, neosporosis, and brucellosis are devastating diseases causing infectious abortion and, therefore, substantial economic losses in farm animals. Toxoplasmosis and neosporosis are caused by the intracellular protozoan parasites Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum), respectively. Brucellosis is a bacterial disease caused by numerous Brucella species in multiple hosts. Toxoplasmosis and brucellosis are also considered foodborne zoonotic diseases. In the current study, specific antibodies to T. gondii and N. caninum, in addition to those to Brucella spp., were detected to gain a better understanding of the epidemiological situation for these three pathogens. Sheep and goat sera from Egypt (n = 360) of animals with and without a history of abortion were tested using commercial ELISAs. Seropositivity rates of 46.1%, 11.9%, and 8.6% for T. gondii, N. caninum, and Brucella spp., respectively, were revealed. Mixed infections with T. gondii and Brucella spp. (4.4%), T. gondii and N. caninum (4.2%), N. caninum and Brucella spp. (1.4%), and even some triple infections (0.6%) have been observed. Animals with a history of abortion had a significantly higher seroprevalence for Brucella spp. infection than those without abortion (12.6%; 28/222 vs. 2.2%; 3/138) (p = 0.0005; Odds ratio = 1.9–21.8), while none of the other pathogens showed a similar effect. This result suggests brucellosis as a possible cause of abortion in the study population. However, the high seroprevalence for T. gondii and N. caninum revealed in our study warrants further investigations.