Diagnosis, prevention and control of a case of Porcine reproductive and respiratory syndrome virus and Porcine circovirus 2 mixed infection with Streptococcus suis type 2

At the end of November 2019,fattening pigs on a commercial pig farm in Hubei showed symptoms such as coughing, wheezing, and dyspnea. In order to find out the cause, control the epidemic and reduce losses, epidemiological investigation, clinical examination, pathological necropsy, and laboratory testing methods were used for comprehensive diagnosis; based on the diagnosis results and specific problems of the pig farm, prevention and control recommendations were put forward. The results showed that the pigs in the affected farm were infected with Porcine reproductive and respiratory syndrome virus NADC 30-like and Porcine circovirus 2,and were simultaneously infected with Streptococcus suis serotype 2. The bacteria isolates were hypersensitive to cephalosporin drugs（ceftriaxone, cefquinome, ceftazidime）,spectinomycin and ampicillin. The condition had been effectively controlled after the implementation of comprehensive prevention and control measures. The results suggested that the main cause of the disease in fattening pigs in this pig farm was the mixed infection of Porcine reproductive and respiratory syndrome virus NADC30-like strain, Porcine circovirus 2 and Streptococcus suis serotype 2, prevention and control should be strengthened.