1.First molecular detection of porcine circovirus type 4 (PCV4) in Malaysia
Tan, C.Y. ; Thanawongnuwech, R. ; Arshad, S.S. ; Hassan, L. ; Lee, C.Y. ; Low, S.E. ; Fong, W.C.M. ; Ooi, P.T.
Tropical Biomedicine 2023;40(No.3):301-306
Porcine circovirus type 4 (PCV4) is the newest member in the porcine circovirus family, first reported in
2020. To date, the presence of PCV4 has only been reported in China, South Korea and most recently
in Thailand. Detection of PCV4 have been reported in various production stages of pigs from piglets,
finishers to sows; associated with a myriad of clinical manifestations including porcine dermatitis and
nephropathy syndrome (PDNS), postweaning multisystemic wasting syndrome (PMWS), respiratory,
enteric and neurological diseases. While successful virus isolation and culture has yet to be reported,
pathogenicity of PCV4 has been demonstrated through infectious clone studies. The objective of this
study is to investigate the presence of PCV4 in Malaysian porcine population to update the epidemiology
of porcine circoviruses in Malaysia. A total of 49 samples from commercial intensive pig farms,
abattoir and wild boar population were subjected to conventional polymerase chain reaction assay to
detect PCV4 capsid (cap) genome. Resulting cap nucleotide sequences were analyzed for maximum
likelihood phylogeny relationship. Results revealed that PCV4 is present in Peninsular Malaysia at a
molecular prevalence of 4.08% (2 / 49 samples). Both PCV4 positive samples originated from clinically
healthy finishers. Malaysian PCV4 strains were classified as genotype PCV4b, and were found to be
phylogenetically distinct from the China, South Korea and Thailand strains. With this latest update of
the novel PCV4 in Malaysia, it is clear that more attention needs to be given to the investigation of
novel porcine circoviruses (PCV) and management of PCV diseases.