Changes in Levels of Viremia in Cattle Persistently Infected with Bovine Viral Diarrhea Virus
| Autor: | Kenny V. Brock, S. R. Bolin, Daniel L. Grooms, Julia F. Ridpath |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
0301 basic medicine
040301 veterinary sciences viruses 030106 microbiology Viremia Biology Virus 0403 veterinary science 03 medical and health sciences Neutralization Tests White blood cell medicine Animals Neutralizing antibody Fetus General Veterinary 04 agricultural and veterinary sciences medicine.disease Virology Titer medicine.anatomical_structure In utero Pestivirus Immunology biology.protein Bovine Virus Diarrhea-Mucosal Disease Cattle Antibody |
| Zdroj: | Journal of Veterinary Diagnostic Investigation. 10:22-26 |
| ISSN: | 1943-4936 1040-6387 |
| Popis: | Virus isolation and serum neutralizing antibody titers were determined over a period of time from samples collected from animals persistently infected with bovine viral diarrhea virus (BVDV). To evaluate over time the ability to detect BVDV by virus isolation from serum or white blood cell preparations, 4 persis- tently infected calves were monitored from birth until 70 days of age. In 3 of 4 persistently infected calves, virus isolation from serum and white blood cells was negative until approximately 42 days of age, when colostral antibody had declined. The level of viremia in 7 adult (.12 months) persistently infected animals decreased by 1 10-fold dilution over at least a 2-year period. The level of viremia became undetectable by virus isolation from serum in 1 of the 7 animals examined. This decline was associated with the development of virus neu- tralizing antibody. Although the level of viremia is fairly stable within persistently infected animals, the presence of specific neutralizing antibody may affect the ability to isolate BVDV. These findings are important when considering diagnostic testing to identify persistently infected animals by virus isolation. An important aspect of the biology and pathogenesis of bovine viral diarrhea virus (BVDV) is persistent infection that occurs following in utero infection of the bovine fetus. The development of persistently infected animals contributes significantly to the high prevalence of BVDV infections. Because persistently infected an- imals are a continuous source of virus, the identifica- tion and removal of persistently infected animals is an essential component of current prevention and control measures. The identification of persistently infected animals is routinely done by virus isolation from white blood cells or serum. To detect noncytopathic BVDV, an im- munoperoxidase microtiter plate assay is commonly used. 1 The presence of low levels of virus or the pres- ence of anti-BVDV antibody may interfere with the ability to isolate BVDV in cell culture from blood samples. 9 Although levels of viremia in persistently infected animals have been characterized, 7 little infor- mation is available on the variability or stability of the viremia in persistently infected animals over time. Therefore, the purpose of this study was to character- ize levels of viremia present in 7 persistently infected cattle over a period of 4 years. In addition, 4 persis- tently infected calves were monitored from birth until 70 days of age. |
| Databáze: | OpenAIRE |
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