Genetic Characterization of Porcine Circovirus Type 2 ( PCV 2) in Pigs of Bhutan

Summary Porcine circovirus ( PCV ) is a small non‐enveloped virus with a single‐stranded circular DNA with two antigenically and genetically different species, PCV 1 and PCV 2. Among these two, PCV 2 is responsible for multifactorial disease syndromes, the most important disease known as PCV 2‐systemic disease ( PCV 2‐ SD ), previously known as post‐weaning multisystemic wasting syndrome ( PMWS ). The epidemiological situation is dynamically changing and new strains including recombinant PCV 2 have emerged in Asia. In Bhutan, pigs are important livestock and play a very important role in providing meat and income for rural farmers. Although high rate of pigs seropositive against PCV 2 was described in Bhutan, there was no virological evidence for PCV 2 infections. This study was conducted to confirm the presence of PCV 2 through detection of PCV 2 DNA and molecular characterization of PCV 2 strains in tissue and blood samples collected from Bhutanese pigs. Porcine circovirus type 2 genome was detected in 16 of 34 tissue samples pigs from the government farm. In 9 pigs, very high level of viral replication indicated that PCV 2‐ SD was detected. Phylogenetic analysis performed with a set of GenBank sequences revealed that the Bhutanese PCV 2 strains belonged to the PCV 2b genotype and grouped with cluster 1C.