New manifestations of swine epidemics emerge, farmers need to be vigilant

With the development of China's @#@227@#@ industry, the gradual increase of foreign pig breeds and the continuous improvement of production intensification have brought new changes to the epidemic situation of swine diseases, which should attract our sufficient attention.

1. With the influx of many foreign pig breeds, new diseases have also followed one after another. In 2001, porcine eperythrozoonosis became pandemic; in 2002, porcine reproductive and respiratory syndrome (blue ear disease) spread widely; in the second half of 2002, circovirus type Z broke out.

2. The seasonality of disease epidemics is gradually fading. Diseases that previously showed obvious seasonal epidemics are now less obviously seasonal. For example, foot-and-mouth disease used to generally occur in winter, but now it occurs all year round.

3. Mutant virus (bacterial) strains are continuously increasing, making disease prevention and control increasingly difficult. The constantly emerging new virus (bacterial) strains differ from one another in immunogenicity, making the preventive effect of existing vaccines uncertain, and the continuously produced new virus (bacterial) strains have ever-increasing resistance to existing drugs.

4. The virulence of virus (bacterial) strains is weakening, and the symptoms are increasingly becoming more insidious. Some viruses (bacteria) have even formed a symbiotic relationship with the host body, showing no disease under normal conditions, but when a new susceptible group is introduced, it will cause a severe outbreak of the disease, resulting in enormous economic losses.

5. The complexity of the disease condition. At present, cases of pigs infected by a single disease hardly exist; they generally manifest as mixed infections or secondary infections caused by multiple pathogens.