RESUMO
The virus isolation-immunoperoxidase test (IPX) on cell cultures and the reverse transcription-polymerase chain reaction (RT-PCR) assay were compared for the detection of bovine viral diarrhoea virus (BVDV) directly in serum samples. Material for this study consisted of 403 sera originating from cattle in 41 BVDV-infected Finnish dairy herds and one suckler cow herd. The presence of virus was demonstrated in 48 samples by both assays. In addition, two more samples were found to be positive by the RT-PCR assay. Both methods proved to be extremely sensitive, detecting pestiviruses even in high serum dilutions, and thus to be suitable for demonstrating the occurrence of persistently infected (PI) cattle. In conclusion, the RT-PCR method used had the advantage of ascertaining BVDV nucleic acid sequences in samples in which the virus had been inactivated, eg during transport or due to the presence of neutralising antibodies.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/diagnóstico , Lentivirus/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/sangue , Bovinos , Células Cultivadas , Embrião de Mamíferos , Técnicas Imunoenzimáticas , Rim , Reprodutibilidade dos Testes , Conchas NasaisRESUMO
To study the pathogenicity of a newly isolated parvovirus of blue fox (Alopex lagopus), pregnant vixens and 43 kits of different ages were experimentally infected with the agent. The kits had no clinical signs of disease, even though most of them excreted virus in their feces, and they responded immunologically to viral exposure. Infection during pregnancy appeared to affect the fetuses. A group of 15 blue fox vixens inoculated with the virus produced a statistically smaller number of kits (78) than did 15 untreated controls (131). Vaccination with a homologous inactivated virus preparation appeared to afford protection against reproductive losses. After infection, 15 vaccinated vixens gave birth to 97 kits, compared with 54 kits born to a similar, non-vaccinated experimental group.
Assuntos
Raposas , Infecções por Parvoviridae/veterinária , Parvoviridae/patogenicidade , Complicações Infecciosas na Gravidez/veterinária , Animais , Feminino , Tamanho da Ninhada de Vivíparos , Parvoviridae/imunologia , Infecções por Parvoviridae/microbiologia , Infecções por Parvoviridae/prevenção & controle , Gravidez , Complicações Infecciosas na Gravidez/microbiologia , Vacinação/veterinária , Vacinas de Produtos Inativados , Vacinas ViraisRESUMO
A latex agglutination (LA) test for the detection of parvoviruses of fur animals, cats, and dogs was developed, and its sensitivity and specificity were compared with those of hemagglutination (HA) and the enzyme-linked immunosorbent assay (ELISA). Tissue culture isolation was used to confirm the specificity results. Fecal samples from various sources were tested, including specimens from raccoon dogs and mink which were experimentally infected with parvoviruses by oral exposure. LA compared favorably with the other tests. The ELISA was the most sensitive. When it was considered as a reference test, the corresponding sensitivities for HA and LA were 96 and 91%, respectively. The specificities were 93% for the ELISA, 95% for the HA test, and 92% for the LA test. LA seems to be a suitable technique for screening animals in the field and in laboratories in which sophisticated techniques are not available.
