Injection can spread infection

摘要

How disease agents spread between pigs, between herds or even between countries became a special theme of the year-2002 world pig health congress. It linked new information about vectors of infection to ideas on how to stop the pathogens being transferred. Most of the reports and comments reflected the fact that the IPVS congress was taking place in the United States. Transmission of the virus of PRRS ranks high among current US concerns. This agent is known to be transmitted primarily by direct pig-to-pig contacts and in contaminated semen. But American evidence has also shown that the act of injecting (such as to administer a vaccine) appears capable of spreading the field virus in some instances from an infected sow to one that was previously virus-free. In University of Minnesota research, the same syringe needle was used in injecting PRRS-affected pigs and others without the infection. Several of the uninfected animals later proved to have the virus. Apparently the needle or syringe had beencontaminated by their contact with a viraemic pig, meaning one with viruses circulating in its bloodstream, and then carried the infection across to the next animal injected.