Canine parvovirus 2 (CPV-2) is a pathogenic virus that infects dogs, causing a highly infectious disease. Monitoring CPV-2 spread is an important part of prevention; however, the prevalence and epidemiological characteristics of CPV-2 have not been systematically evaluated and analyzed in mainland China. Therefore, a systematic review and meta-analysis were performed to assess prevalence and epidemiological characteristics of CPV-2 in domestic dogs in mainland China.
In this study, Chinese and English literature on CPV-2 epidemiology published between January 2006 and December 2019 was evaluated. Regarding meta-analysis, the random-effect model was employed by forest plot with 95% of confidence interval. The number of CPV-2 infections was identified and the pooled prevalence of infection, as well as the epidemiological characteristics, was calculated using meta-analysis.
A total of 39 studies (data from 137,844 dogs) met the evaluation criteria and were used in our study. The pooled prevalence of CPV-2 infection in mainland China was 36%. CPV-2 infection were associated with age, breed, sampling season and immunization status, but not with gender, publication time and diagnostic methods.
Our results indicated that CPV-2 is prevalent among dogs in China. It is therefore necessary to carry out continuous surveillance and epidemiological studies of CPV-2. In addition, accordingly, effective measures should be taken to prevent the transmission and spread of CPV-2 among the Chinese dog population.

Canine parvovirus infection remains to represent a worldwide and commonly occurring infectious disease leading to severe morbidity especially in puppies. The main therapeutic approach is primarily based on symptomatic treatment, especially addressing acute gastrointestinal signs as well as treating and preventing potential sepsis due to bacterial translocation. Besides antibiotic and essential fluid therapy, the use of efficient antiemetic and pain medication is required. In addition, early enteral nutrition should be attempted as this has been shown to be associated with a shorter time to recovery. Modulation of the intestinal microbiome could improve clinical signs and possibly aide in avoiding long-term sequelae such as chronic gastrointestinal disease. Treatment with recombinant feline interferon-omega resulted in a lower mortality and a more rapid improvement of clinical signs in several experimental and clinical studies and thus is considered to be effective.
Die kanine Parvovirose ist nach wie vor eine weltweit verbreitete und vor allem bei Welpen häufig auftretende Infektionskrankheit. Die Therapie erfolgt überwiegend symptomatisch und beinhaltet die Behandlung der akuten gastrointestinalen Symptome sowie die Behandlung und Prävention einer möglichen Sepsis aufgrund bakterieller Translokation. Neben der antibiotischen Behandlung und der essenziellen Flüssigkeitstherapie ist eine ausreichende antiemetische und analgetische Medikation sinnvoll. Weiterhin sollte eine möglichst frühzeitige enterale Ernährung angestrebt werden, da dies die Genesungszeit verkürzt. Die gezielte Modulation der intestinalen Mikrobiota kann die klinische Symptomatik reduzieren und möglicherweise langfristige Folgen, wie chronische Darmerkrankungen, verhindern. Eine antivirale Therapie mit dem rekombinanten felinen Interferon-Omega führte in mehreren Studien zu einer geringeren Mortalitätsrate und einer schnelleren Besserung der klinischen Symptome.

Severe gastroenteritis caused by canine parvovirus type 2 (CPV2) is a serious life-threatening disease in puppies less than 4-months of age. The emergence of new variants has provoked some concern about the cross-protection elicited by licensed canine parvovirus modified-live type 2 (CPV2) and type 2b (CPV2b) vaccines against the most recent subtype CPV2c. A systematic review was carried out to assess the efficacy of commercial vaccines. We conducted a literature search of Pub Med/MEDLINE from January 1990 to May 2014. This was supplemented by hand-searching of related citations and searches in Google/Google Scholar. Controlled clinical trials in which vaccinated puppies were challenged with CPV2c virus were evaluated. Reporting of outcome measures and results for vaccine efficacy were critically appraised through a variety of clinical signs, serological tests, virus shedding and the ability to overcome maternally derived antibodies (MDA) titres. Six controlled clinical trials were included in the review. In most cases, the results of the selected studies reported benefits in terms of clinical signs, serological tests and virus shedding. However, MDA interference was not considered or evaluated in 5 of the selected trials. No accurate definitions of baseline healthy status and/or clinical outcomes were provided. Methods of randomization, allocation concealment and blinding were usually poorly reported. As a result of the limited number of included studies matching the inclusion criteria, the small sample sizes, short follow-up and the methodological limitations observed, it was not possible to reach a final conclusion regarding the cross-protection of licensed CPV2 and CPV2b vaccines against the subtype 2c in puppies. Further and specifically designed trials are required in order to elucidate whether cross-protection is acquired from licensed CPV vaccines.

Canine parvovirus (CPV-2), first recognized in 1978 as a new pathogen of dogs, was probably derived from a very closely related virus in cats, feline panleukopaenia virus (FPLV) or a closely related carnivore parvovirus (FPLV-like virus). CPV-2 is responsible for either myocarditis or fatal gastroenteritis in pups with high morbidity and mortality. Shortly after its emergence, CPV-2 has become endemic in the global dog population. The original CPV-2 continued to evolve, and was subsequently replaced by three different but closely related antigenic variants, designated CPV-2a, CPV-2b and CPV-2c, which now coexist in dog populations worldwide. The genetic and antigenic variation in CPV-2 also correlated with changes in the host range and tissue tropisms of the virus. Here, we reviewed variation and evolution of CPV-2 in past 30 years and discussed CPV-2 as an important model to study virus evolution.

Canine parvovirus type 2 (CPV-2) emerged in late 1970s causing severe epizootics in kennels and dog shelters worldwide. Soon after its emergence, CPV-2 underwent genetic evolution giving rise consecutively to two antigenic variants, CPV-2a and CPV-2b that replaced progressively the original type. In 2000, a new antigenic variant, CPV-2c, was detected in Italy and rapidly spread to several countries. In comparison to the original type CPV-2, the antigenic variants display increased pathogenicity in dogs and extended host range, being able to infect and cause disease in cats. Epidemiological survey indicate that the newest type CPV-2c is becoming prevalent in different geographic regions and is often associated to severe disease in adult dogs and also in dogs that have completed the vaccination protocols. However, the primary cause of failure of CPV vaccination is interference by maternally derived immunity. Diagnosis of CPV infection by traditional methods has been shown to be poorly sensitive, especially in the late stages of infections. New diagnostic approaches based on molecular methods have been developed for sensitive detection of CPV in clinical samples and rapid characterisation of the viral type. Continuous surveillance will help assess whether there is a real need to update currently available vaccines and diagnostic tests.