The Epidemiology Investigation Of Canine Parvovirus Infection In Guangxi

In order to understand the epidemiology of canine parvovirus disease in Guangxi,and discover and master the epidemic situation in time,From January 1,2015 to December 31,2017,there are 11,861 canine infectious virus diseases(mainly canine distemper virus(CDV),canine parvovirus(CPV),and canine coronavirus(CCV))and their 7107 cases of canine parvovirus mono-infection and co-infection were investigated from the outpatient records in Guangxi.The results showed that canine parvovirus infection has differences in gender,age,breed,season and immune status,among which the incidence of male dogs was high,and the incidence was high in puppies and purebred dogs from February to March,dogs and unvaccinated dogs have a high incidence from March to May.In this study,a PCR method for rapid detection of canine parvovirus was established.The minimum virus DNA detection limit of PCR was 5-6x6.1342 ng/μL.Randomly collected 120 animal diseases were diagnosed of canine parvovirus by colloidal gold immunochromatography from Guangxi between 2016 and 2017.And use the established PCR detection method to conduct secondary tests for 120 diseased animals and the animals were all positive and the detection rate was 100%.PCR detection of CPV has a higher sensitivity,and colloidal gold immunochromatography is more rapid and simple in clinical.The CPV subtype analysis of CPV VP2 gene sequencing results of 120 clinical materials in different regions of Guangxi showed that CPV-2c subtypes accounted for 59.17%(71/120),CPV-2a subtypes accounted for 25.83%(31/120),and CPV-2b subtype accounted for 15%(18/120),indicating that the predominant CPV subtypes are CPV-2c and CPV-2a in Guangxi between 2016 and 2017,while the proportion of CPV-2b is lower,and there is no CPV-2 subtype,which is the first time that CPV-2c has been found in Guangxi;Nucleotide sequences and amino acid sequence homology between the isolates and the reference strains were high.Randomly selected 10 samples for CPV whole-genome sequenced from 120 samples(faeces)DNA of VP2 gene identified were positive by PCR.The sequencing results showed that the nucleotide homology of the whole gene was high,and the amino acid homology was high and low.While the nucleotide and amino acid homology of VP2 was higher.Combined with the clinical symptoms,we can see that the clinical symptoms of the dogs corresponding to these 10 samples are consistent with the clinical symptoms of canine parvovirus disease,so the site where CPV plays an antigenic determinant on the VP2 fragment is consistent with the report.In summary,the molecular epidemiological investigation and genetic difference analysis of canine parvovirus in Guangxi region can lay a theoretical foundation for exploring the causes of clinical immune failure and targeted development of CPV vaccines for pets.