Genetic analysis and emergence of canine parvovirus type 2c in South Eastern Nigeria

Background: Genetic analysis of canine parvovirus type 2 (CPV-2) variants circulating in South Eastern Nigeria was investigated. The original strain of CPV-2 emerged in 1978, mutated later to CPV-2a and has continued to be evolved. Aims: To genetically characterize CPV-2 strains detected in dogs in South Eastern Nigeria and to phylogenetically group the viruses with existing sequencing data. Methods: A total number of 82 rectal swabs were collected and stored in virus transport medium (VTM) from suspected cases of CPV-2 within the study area and were tested with polymerase chain reaction (PCR). Results: Seventy-nine samples (96.3%) were positive for CPV-2 and sequence analysis of partial VP2 gene of 20 amplicons revealed circulation of CPV-2a (n=4) and CPV-2c (n=16) in the region. The obtained strains clustered together. However, the group was further divided into two clear clusters comprising of 2a and 2c strains. The vaccine strain and the CPV-2 reference strains from USA formed a monophyletic cluster. Conclusion: Canine parvovirus types 2a and 2c are co-circulating in South Eastern region of Nigeria and therefore, there is an urgent need for an improved vaccine to cover for the emerging strain (CPV-2c) in Nigeria.