Molecular Epidemiological Survey of Canine Parvovirus Circulating in
China from 2014 to 2019
Abstract
The global distribution of canine parvovirus (CPV-2), derived from a
closely related carnivore parvovirus, has caused a considerable threat
to the dog population. The virus continuously underwent genetic
evolution, giving rise to several variants. To investigate the
prevalence of Chinese CPV-2 strains in recent years, a total of 25 CPV-2
strains were isolated from 33 canine samples collected from 2018 to
2020, and then sequenced and analyzed. Two variants, New CPV-2a and
CPV-2c were identified. Contrary to previous reports, the CPV-2c variant
has gained an epidemiological advantage over the New CPV-2a variant in
China. To make up for the relatively limited sample, 683 Chinese CPV-2
records identified between 2014 to 2019 were retrieved from Genbank and
associated publications, whose result further supported our finding.
That should be caught concern since the CPV-2c variant has been
frequently related to vaccine failure in adult dogs. VP2 protein
sequences analysis revealed several amino acid substitutions, including
Ala5Gly, Pro13Ser, Phe267Tyr, Tyr324Ile, Gln370Arg, Thr440Ala, and
Lys570Arg. Phylogenetic analysis indicated a close relationship between
Chinese strains with Asian strains, suggesting the mutual transmission
between Asian countries. Furthermore, the intercontinental transmission
should be a cause for concern. Surprisingly, two feline panleukopenia
(FPLV) strains with Ile101Thr mutation in VP2 protein were also
successfully isolated from canine fecal samples, which was considered
incapable of infecting dogs. This study clarified the epidemic
characteristics of Chinese CPV-2 strains between 2014 and 2019, offering
a reference for epidemic control. Besides, the detection of FPLV in
canine samples may provide information for future studies on the
evolution of carnivore parvovirus.