Eradicating bovine viral diarrhoea virus
Bovine viral diarrhoea virus (BVDV) causes widespread infection of cattle populations worldwide and, even though the majority of infections go unnoticed, is an important disease. BVDV infection impacts on animal welfare and causes significant economic losses. Approximately 1 per cent of cattle are persistently infected with BVDV and are the major source of infection within a herd. Persistently infected cattle can be clinically normal yet shed high titres of infectious virus. BVDV naive animals may succumb to acute infection, usually due to contact with a persistently infected animal. By contrast, the spread of the virus by animals with acute infection may be quite inefficient. The lesson from countries such as Norway is that eradication can be achieved. Complex logistical issues must be resolved in order to mount a successful national eradication campaign, and coordination of resources is a major challenge, but, as other countries have shown, we have sufficient knowledge of this virus to eliminate the sources of infection.