Toxoplasma gondii in Chickens (Gallus domesticus) from North India.

PURPOSE

Toxoplasma gondii, an important food-borne parasite has been reported in a wide range of food animals globally. Poultry meat production is on rise in several developing nations including India. Several studies on status of T. gondii conducted globally had shown substantial risk of this parasite through poultry meat. Such information is lacking in the north India, where poultry meat is a preferred non-vegetarian food over other meats; therefore, this study determined the seroprevalence (based on detection of antibodies) and tissue prevalence (based on detection of DNA) of T. gondii in poultry meat intended for human consumption in north India.

METHODS

Samples (skeletal muscle and/heart as well as blood) were collected from slaughter poultry intended for human consumption reared in Punjab state (n = 366), Himachal Pradesh (n = 44) state, and Chandigarh union territory (n = 112) in North India. Serum samples were tested using commercially available Chicken T. gondii IgG ELISA kit to determine the serostatus. The DNA of T. gondii was detected by nested PCR. To determine the agreement between ELISA and PCR, Kappa value was estimated.

RESULTS

Overall, study reports 2.3% (95% CI 1.3%-4.1%) tissue prevalence and 6.5% (95% CI 4.6%-9.1%) seroprevalence from chickens reared in north India. Backyard poultry had significantly higher proportion of T. gondii (24.4%, 10/41; p < 0.001) than caged (0%, 0/284) and deep litter poultry (16.2%, 32/197). The sequence alignment score of three sequences obtained in this study showed 97-100% nucleotide identity with Type I RH strain and VEG type III strain. The agreement between ELISA and PCR was poor (Kappa = 0.145; 95% CI 0.07-0.22). Thus, a combination of serological and molecular tests can improve the diagnosis of T. gondii.

CONCLUSION

A low prevalence indicates that T. gondii in poultry presents a lower food safety risk for public health in north India; however, this study recommend cooking of poultry meat before consumption. Further studies are required to check the viability of T. gondii in poultry meat intended for human consumption, and to determine the risk factors associated and the genotypes circulating in poultry in north India.