Epidemiological features and economical importance of bovine virus diarrhoea virus (BVDV) infections

Authors
Citation
H. Houe, Epidemiological features and economical importance of bovine virus diarrhoea virus (BVDV) infections, VET MICROB, 64(2-3), 1999, pp. 89-107
Citations number
96
Categorie Soggetti
Veterinary Medicine/Animal Health",Microbiology
Journal title
VETERINARY MICROBIOLOGY
ISSN journal
03781135 → ACNP
Volume
64
Issue
2-3
Year of publication
1999
Pages
89 - 107
Database
ISI
SICI code
0378-1135(199901)64:2-3<89:EFAEIO>2.0.ZU;2-R
Abstract
Infections with bovine virus diarrhoea virus (BVDV) are widespread througho ut the world. Although the prevalence of infection varies among surveys, th e infection tends to be endemic in many populations, reaching a maximum lev el of 1-2% of the cattle being persistently infected (PI) and 60-85% of the cattle being antibody positive. Persistently infected cattle are the main source for transmission of the virus. However, acutely infected cattle as w ell as other ruminants, either acutely or persistently infected, may transm it the virus. Transmission is most efficient by direct contact. However, as infections have been observed in closed, non-pasturing herds, other transm ission routes seem likely to have some practical importance. Differences in BVDV prevalence among regions or introduction of virus in herds previously free of BVDV are often associated with particular epidemiological determin ants such as cattle population density, animal trade and pasturing practice s. However, on a few occasions there have been no obvious explanations for infection of individual herds. Estimates of economic losses due to BVDV inf ection vary depending on the immune status of the population and the pathog enicity of the infecting virus strains. Introduction of the infection into a totally susceptible population invariably causes extensive losses until a state of equilibrium is reached. Infection with highly virulent BVDV strai ns causing severe clinical signs and death after acute infection gives rise to substantial economical losses. At an estimated annual incidence of acut e infections of 34%, the total annual losses were estimated as US$ 20 milli on per million calvings when modeling the losses due to a low-virulent BVDV strain. At the same incidence of infection, the losses due to a high-virul ent BVDV strain were estimated as US$ 57 million per million calvings. Low- virulent BVDV infections caused maximum losses at an incidence of 45%, wher eas high-virulent BVDV infections caused maximum losses at an incidence of 65%. Thus, cost-benefit analyses of control programs are highly dependent o n the risks of new infections under different circumstances and on the stra ins of the virus involved. (C) 1999 Elsevier Science B.V. All rights reserv ed.