ABSTRACT
OBJECTIVE: To investigate how different sampling techniques affect detection of DNA from feline herpes virus Type 1 (FHV-1), Chlamydophila felis and Mycoplasma felis and to study the correlation between positive test results and clinical signs in cats. ANIMALS: Fifty-one cats; 24 with ocular signs and 27 healthy control cats. PROCEDURES: Samples were collected from all cats using cotton swabs, conjunctival and corneal biopsies, and corneal scrapings. Samples were analyzed for presence of FHV-1, C. felis, M. felis, and feline DNA, defined by 28S rDNA, by using real-time PCR. RESULTS: In affected cats, FHV-1 was detected in only one cat; C. felis and M. felis were not detected in any affected cats. None of the three organisms was detected in any control cats. Feline DNA was demonstrated in all conjunctival samples, in 82% of corneal swabs, 92% of corneal scrapings, and 100% of keratectomy samples. CONCLUSIONS: Because of the generally low detection rate for FHV-1, C. felis, and M. felis DNA in this study, differences regarding sampling technique could not be determined and correlation between positive test results and degree of clinical signs could not be made. Detection of feline DNA in most samples irrespective of sampling technique, suggests a low prevalence of FHV-1, C. felis and M. felis in this population of cats.
Subject(s)
Cat Diseases/diagnosis , Herpesviridae Infections/veterinary , Polymerase Chain Reaction/veterinary , Varicellovirus/isolation & purification , Animals , Case-Control Studies , Cat Diseases/epidemiology , Cats , Chlamydophila/isolation & purification , Chlamydophila Infections/diagnosis , Chlamydophila Infections/epidemiology , Chlamydophila Infections/veterinary , Conjunctivitis/diagnosis , Conjunctivitis/epidemiology , Conjunctivitis/veterinary , Corneal Diseases/diagnosis , Corneal Diseases/epidemiology , Corneal Diseases/veterinary , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Female , Herpesviridae Infections/diagnosis , Herpesviridae Infections/epidemiology , Male , Mycoplasma/isolation & purification , Mycoplasma Infections/diagnosis , Mycoplasma Infections/epidemiology , Mycoplasma Infections/veterinary , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/standards , Prevalence , RNA, Ribosomal, 28S/chemistry , RNA, Ribosomal, 28S/genetics , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
During a study on Bovine Viral Diarrhoea (BVD) epidemiology in Thailand, a pestivirus was detected in serum from a calf. Comparative nucleotide sequence analysis showed that this virus was closely related to a recently described atypical pestivirus (D32/00_'HoBi') that was first isolated from a batch of foetal calf serum collected in Brazil. The results from virus neutralisation tests performed on sera collected from cattle in the herd of the infected calf, showed that these cattle had markedly higher antibody titres against the atypical pestivirus 'HoBi' than against Bovine Viral Diarrhoea Virus types 1 and 2, or Border Disease Virus. The results also supported, consequently, the results from the molecular analysis, and demonstrated that a 'HoBi'-like pestivirus had been introduced to, and was now circulating in the herd. This study is the first to report a natural infection in cattle with a virus related to this atypical pestivirus, and it suggests that this group of pestiviruses may already be spread in cattle populations. The findings have implications for BVD control and for the biosafety of vaccines and other biological products produced with foetal calf serum. Consequently, these atypical pestiviruses should be included in serological assays, and any diagnostic assay aimed at detection of pestiviruses in biological products or animals should be tested for its ability to detect them.
