Vol. 12, Special Issue 9 (2023)

Porcine circovirus-2 (PCV2) infections in pigs are endemic in India and cause a variety of adverse health effects ranging from ill-thrift, growth retardation to reproductive failure. The virus is present as sub-clinical infection even in healthy herds. Worldwide, eight genotypes of PCV2 have been identified from PCV2a to 2h and additional genotypes and recombinant types have been proposed. This study reveals that six genotypes of PCV2, viz, PCV2a, PCV2b, PCV2d, PCV2f, PCV2g, PCV2h and a few recombinant strains, are reported from India. However, genotypes PCV2c and PCV2e are not detected in India. Based on data from Genbank, strains of PCV2d genotype are the predominant circulating genotype in India (55.64%), with two distinct clades; one of which is found predominantly in the north east and another in south of India. Among the recently delineated genotypes, PCV2f and PCV2g are detected in the north east of India, with PCV2g strains being phylogenitically related to PCV2d strains and PCV2f being phylogenetically related to PCV2a strains. The PCV2h strains, another recently categorized genotype, are so far not detected in the north east of India. The PCV2h are phylogenitically aligned with PCV2b strains. The PCV2b and PCV2a genotypes are lesser in proportion among the circulating Indian PCV2 strains.