Toxoplasma gondii in backyard pigs: seroepidemiology and mouse bioassay

Abstract

The aim of this study was to evaluate the occurrence of Toxoplasma gondii in backyard pigs destined for human consumption in Pernambuco state, Brazil. Blood and tissue samples (liver, heart, brain, lung and diaphragm) were collected from 224 pigs from legal slaughterhouses and tested for T. gondii infection. Antibodies to T. gondii were found in the sera of 37.9% (85/224) by using the immunofluorescence antibody test (cut-off - 1:64). Tissue samples from seropositive pigs were bioassayed in mice. Tissue samples from seropositive pigs and from mice of the bioassay were submitted to histopathology, immunohistochemistry, polymerase chain reaction (PCR) and sequencing; 14.1% of pig tissue samples and 27.7% of bioassayed mouse samples were positive for T. gondii DNA, but all pig and mouse tissues were negative in histopathology analysis and immunochemistry. By using a risk assessment questionnaire, there was significant difference (p<0.001) in seroprevalence of 21.2% (reproducer) and 3.1% (finishing pig). These data serve as indicative of the sanitary conditions and risk of T. gondii infection for backyard pigs. Preventive measures must be implemented by health services to avoid toxoplasmosis human cases due to ingestion of pig meat.

Antibodies anti-Toxoplasma gondii and anti-Neospora caninum in backyard pigs from the state of Mato Grosso, Brazil

“…We observed that more than half of studied farms (55.63% of herd seroprevalence) had at least one animal testing positive for anti-T. gondii antibodies. Moreover, a high rate seroprevalence (32.48%) in the total population of the present study was similarly observed in a previous survey performed in the western Amazon (CAVALCANTE et al, 2006);southern (CADEMARTORI et al, 2014) and northeastern (SAMICO-FERNANDES et al, 2017) regions from Brazil, where pigs were raised in similar conditions. Table 3.…”

Prevalence, molecular detection and risk factors investigation for the occurrence of Toxoplasma gondii in slaughter pigs in North India

“…Surveys conducted in pigs globally recorded sero-prevalence varied from 0 to 92.7% ([5, 15];). High seroprevalence of T. gondii in pigs (48%) from Chandigarh was corroborated with other reports in pigs from India India and elsewhere [4, 32]. However, low seroprevalence was reported in pigs from Haryana, another north Indian state [34]; this variation in seroprevalences could be attributed to difference in the serological methodology, geography, management practices and sample size.…”

“…PCR was used to detect T. gondii DNA in the tissues of pigs, but this method does not detect the viability of the parasite. Previously, viable T. gondii has been isolated from pork in Haryana, another north Indian state and elsewhere [14, 22, 32]. Further studies are required to isolate viable T. gondii in the pork samples destined for human consumption from North India.…”

High level of infection by Toxoplasma gondii in pigs slaughtered in the city of São Luís, Maranhão

“…Thus, even though the animals were subjected to different ways of slaughter, it is possible that they had been reared under conditions presenting similar risk factors. Previous studies have shown the importance of proper management on pig farms in relation to T. gondii infection (Samico-Fernandes et al, 2017;Gazzonis et al, 2018). Dubey (2009) pointed out that the determining factor in infection among pigs does not come from the rearing system itself, but from the exposure of these animals to oocysts and/or rodents in the environment.…”