Occurrence of canine parvovirus type 2c in the United States.
Canine parvovirus (CPV) type 2 (CPV-2) emerged around 1978 as a major pathogen of dogs worldwide. In the mid-1980s, the original CPV-2 had evolved and was completely replaced by 2 variants, CPV-2a and CPV-2b. In 2000, a new variant of CPV (named CPV-2c) was detected in Italy and now cocirculates with types 2a and 2b in that country. The CPV-2c has also been reported from single outbreaks in Vietnam and Spain. This study was conducted to determine if CPV-2c occurs in the United States. Thirty-three fecal samples were collected from dogs in 16 states between April 2006 and April 2007 and were tested for CPV using real-time polymerase chain reaction (PCR). Positive samples were further tested using conventional PCR and minor-groove binding TaqMan PCR assays to determine the viral type and to differentiate vaccine strains from field strains. Twenty-seven samples were positive for CPV, 7 of which were CPV-2c from 5 states: Arizona, California, Georgia, Oklahoma, and Texas. Of the 7 isolates, 4 differed from European CPV-2c isolates by 2 additional single-nucleotide mutations at positions 4076 and 4104, the latter of which produces a ThrAla change at residue 440 located near a major antigenic site. The coast-to-coast geographic distribution of the states in which CPV-2c was detected strongly suggests that this new CPV variant is probably widespread in the United States. The continuous evolution of CPV requires that monoclonal antibody-based and nucleic acid-based diagnostic assays should be periodically checked for sensitivity on prevalent CPV strains.
Hong
Charles
C
Athens Veterinary Diagnostic Laboratory, University of Georgia, Athens, GA 30602, USA.
Decaro
Nicola
N
Desario
Costantina
C
Tanner
Patrick
P
Pardo
M Camila
MC
Sanchez
Susan
S
Buonavoglia
Canio
C
Saliki
Jeremiah T
JT
D000818:Animals; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics; D004283:Dog Diseases / Q000453:epidemiology* / Q000821:virology*; D004285:Dogs; D008969:Molecular Sequence Data; D010322:Parvoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D017993:Parvovirus, Canine / Q000145:classification*; D014481:United States / Q000453:epidemiology