EPIDEMIOLOGY OF BOVINE VIRAL DIARRHEA VIRUS

This review outlines the geographic distribution of infection and offe rs possible explanations for differences in occurrence of infection. E xperimental studies have shown that there are many possible means of t ransmission of infection. Direct contact with animals persistently inf ected (PI) with bovine viral diarrhea virus (BVDV) is probably the mos t important method of transmission of infection. However, field studie s have shown that some limited spread of infection also occurs in the absence of PI animals. Clinical symptoms after BVDV infection often oc cur within certain time limits, which may help to make the herd diagno sis. Surveillance of infection status at the herd level is also possib le using serology because of the extensive transmission of infections from PI animals. The high incidence of infection combined with the dif ferent damages that are seen after BVDV infection cause huge economic losses.