Porcine Epidemic Diarrhea [PED (Porcine Epidemic Diarrhea)] is an acute, highly contagious intestinal infectious disease caused by an infectious pathogen-Porcine Epidemic Diarrhea virus. The harm caused to breeding users is more serious, so why is it difficult to prevent and control swine epidemic diarrhea?

The hazard of the virus: diseased pigs, negative pigs and clinically recovered pigs can be the source of infection to spread the virus, and fecal-oral transmission is the main route of transmission. Spring and winter are the frequent seasons of the disease. The disease is particularly harmful to suckling piglets, and the fatality rate can be as high as 100%.

The complexity of the strain: Although the virus has a high infection rate, it is very difficult to isolate and culture the virus in vitro, and the isolation success rate is extremely low. Even if the virus is successfully isolated, it is often difficult to achieve a high proliferation titer. , And it is more likely to lose the infectivity of the virus in the process of cell subculture.

Limitations of diagnosis: At present, pathogenic diagnosis is mainly through immunoelectron microscopy, RT-PCR, immunofluorescence, immunohistochemistry and other methods. Serological detection is mainly through enzyme-linked immunosorbent test, serum neutralization test, etc. Among them, immunofluorescence, serum neutralization experiments, immunohistochemistry and other methods are time-consuming and labor-intensive, and are not suitable for large-scale clinical testing. The method of immunoelectron microscopy requires the help of electron microscopy equipment, and its application also has certain limitations.

The diarrhea problem that plagues the aquaculture industry recurs and is difficult to control, mainly because PEDV is constantly mutating, and its virulence continues to increase, showing more and more lethality. At present, my country is dominated by variant strains of the G2 subgroup, and the prevalence rate is over 90%. However, due to the low homology between the classic strain vaccine and the epidemic strain, it cannot provide complete protection. Therefore, it is recommended that pig raisers choose diarrhea vaccines against mutant strains. "If the strain is good, the vaccine is good; the price of the virus is high, the vaccine is better!" In addition to strain matching, the higher the virus content of the vaccine, the stronger the protection of the pig herd. In addition, in addition to immunizing diarrhea vaccines, it is necessary to strengthen feeding management and adopt strict biosecurity measures. In terms of environment, pig farmers must ensure that the environmental temperature and humidity of the pig house are appropriate, and ensure that they provide good and hygienic feed and drinking water for the pigs. As for biosafety, in addition to the usual environmental disinfection and fecal cleaning, sows need to undergo strict disinfection measures and milking during littering. This is to cut off the transmission route of PED milk and oral cavity.