Molecular characterization and risk factors associated with abortions caused by Toxoplasma gondii in goats in Chittagong

Abstract

The current research was conducted to assess the seroprevalence, associated risk factors and molecular characterization of Toxoplasma gondii in goats in Chittagong City Corporation area (CCCA). 52 farms were selected on the basis of previous abortion history. Among these farms a total of 400 blood sample was collected to detect specific IgG against Toxoplasma gondii by ELIZA. For molecular characterization 20 aborted fetus of goat were collected those were admitted into SAQVTH, CVASU. The overall seroprevalence of toxoplasmosis in goat was 28.3%. The prevalence of infection was significantly higher in adults (OR=3.1, 95% CI:1.20,8.23; P=0.02) than in young goats, goats with poor BCS (OR=3.3, 95% CI: 1.2,8.8, P<0.01) than good BCS. Farm management like allowed to drink from stagnant water (OR=26.9, 95% CI:6.2,117.1, P<0.01) than those provided tap water, absence of feeding trough (OR=10.3, 95% CI:1.4,78.1, P<0.05) as compared to wooden and steel troughs, absence of drinking troughs (OR=3.2, 95% CI:1.2,8.7, P<0.05) than those use steel or plastic trough were statistically significant with T. gondii infection. Presence of cat in farm (OR=20.9, 95% CI:6.2,70.5, P<0.01) might play a vital role for the transmission of this infection. Goats of flooded areas had a significantly higher prevalence of toxoplasmosis than hilly and flat areas. In order to conduct histopatological examination and molecular characterization samples from placenta, fetal heart, lungs, liver, brain tissue was collected. Histopathological examination revealed bradyzoite cyst and tachyzoite cyst from some of brain and heart tissues. A nested PCR assay targeting B1 gene was applied and positive sample yield 197 bp amplification products consistent with T. gondii. In case of aborted fetus, the frequency of toxoplasmosis was 35%. Among the aborted cases, 50% abortion occurred at >3.5 months of gestation by T. gondii. In risk factor study, age of goats, presence of cat, BCS were not found as an influencing factors of toxoplasmosis in aborted does. The presence of T. gondii in fetal tissues along with characteristic histopathological changes strongly suggested active and or congenital toxoplasmosis. It can be concluded that exposure of goats to oocysts of T. gondii is widespread. Further studies to determine the genotype of the parasite, public health significance both in livestock and human are recommended.