Dynamics of natural infection by Toxoplasma gondii in goat herds in the semiarid region of northeastern Brazil: transitional antibody observation.

This study aimed to describe the transmission of T. gondii in naturally infected goats in the semiarid region of northeastern Brazil, through evaluating the serological status of these animals from one to 12 months of age. Seven goat farms were selected. During the first visit, an epidemiological questionnaire was applied. Blood samples were collected from pregnant goats and from their female offspring every month, to monitor them for anti-T. gondii antibodies, using the indirect fluorescence antibody test (IFAT). Out of 66 pregnant goats evaluated, 47% (31/66) (95% CI: 34.6% - 59.7%) were positive and out of 93 female offspring, 61.3% (57/93) (95% CI: 52.4% - 69.2%) were positive, in at least one month during the evaluation period. Among the positive female offspring, 43.3% (27/57) (95% CI: 39.7% - 56.9%) presented environmental infection and 56.7% (30/57) (95% CI: 43.4% - 66.3 %) probably had only colostral antibodies or vertical transmission. It was observed that 92,6% (25/27) from environmental infections occurred until reproductive age (six months) (p<0.0001). It was also noted that there is a correlation between the titration of mothers and offspring, until four months of age (p<0.0001). Large fluctuations in the presence of antibodies were observed among the animals over the months monitored. It can be concluded that the prevalence of anti-T. gondii antibodies within the herds was greater than what has been expressed in specific prevalence studies and that most goat become infected up to the six months of life in the studied area.

Seroprevalence and isolation of Toxoplasma gondii in sheep intended for human consumption in Paraíba, northeastern Brazil.

Toxoplasma gondii is a zoonotic parasite capable of infecting almost all warm-blooded animals. Currently, studies assessing the viability of cysts present in sheep meat are still scarce, especially in the northeastern region of Brazil. Therefore, the aim of this study was to evaluate the seroprevalence of anti-Toxoplasma gondii antibodies, isolate the parasite from tissue samples, and determine factors associated with infection of sheep intended for human consumption in the state of Paraíba, northeastern Brazil. Serum samples from 205 sheep slaughtered in Paraíba were tested using the indirect fluorescence antibody test (IFAT ≥ 64) for the presence of anti-T. gondii antibodies. Among the animals sampled, 30.7% (63/205) were seropositive, with antibody titers ranging from 1:64 to 1:16384. Sixty-one bioassays were performed in mice, and an isolation rate of 47.5% (29/61) was obtained. The infection was lethal to at least one infected mouse in 24.1% (7/29) of the bioassays. The mean length of survival of infected mice was 36.4 days. Females (OR = 3.183; CI = [1.452-6.976]), extensive breeding system (OR = 2.612; CI = [1.120-6.094]), and purebred animals (OR = 2.157; CI = [1.009-4.612]) were considered to be factors associated with infection. These results revealed that the prevalence of anti-T. gondii antibodies and the percentage of viable cysts recovered from sheep destined for human consumption in Paraíba, northeastern Brazil, were high.