Prevalence and molecular epidemiology of porcine cysticercosis in naturally infected pigs (Sus scrofa) in Punjab, India.

Porcine cysticercosis is a serious zoonosis in resource-poor countries. Despite the evidence showing that the disease is endemic in the Punjab region of India, molecular characterisation of Taenia solium cysticercosis from naturally infected pigs has not been carried out. The authors examined a total of 519 pigs slaughtered in small slaughter shops (shops that sell meat from animals that are slaughtered on the premises as the customer waits) in the urban slums of Punjab state in northern India. The expected polymerase chain reaction products with molecular sizes of 286 bp, 420 bp, 1150 bp and 333 bp corresponding to the targeted large subunit ribosomal RNA (rRNA), cytochrome oxidase 1, internal transcribed spacer 1, and diagnostic antigen Ts14 genes, respectively, were amplified from the cysts collected from all 22 infected carcasses. The detection limits for the respective primers (except those targeting the Ts14 gene) were estimated. The analytical sensitivities of both the TBR and JB primers (targeting the rRNA and cytochrome oxidase genes, respectively) were found to be higher (10 pg) than that of the internal transcribed spacer 1 gene (1 ng) primers. Ten representative samples from cytochrome oxidase 1 gene amplified products were sequenced in both directions for phylogenetic analysis. Sequencing demonstrated that all cysticerci were of the Asian genotype of T. solium and not of the African/Latin American genotype or T. asiatica. The results confirm the presence of T. solium porcine cysticercosis in Punjab state and there is therefore an urgent need for science-based policies for prevention and control of this serious zoonosis.