Detection And Analysis On Major Disease Mixed Infection With PRRS In The Western Region Of Henan Province And The Approach Of Prevention And Control

Porcine reproductive and respiratory syndrome(PRRS) is a kind ofimmunosuppressive infectious diseases, which was characterized by reproductivefailure in sows and respiratory illness in piglets. The PRRS was first discovered in1987in the United States, spread around the world quickly, resulted in a shocking lossto the swine industry. Recently, there was a new challenge to prevent and control ofthe pathogenetic pig of PRRS because of infecting other immunosuppressive infectiousdiseases(PCV2, CSF, PR, etc) and increased.In this study,170pieces of suspected PRRS samples from the western region ofHenan province were detected by RT-PCR, later the pathogens (PCV2, CSFV and PRV)were detected by the PCR and the RT-PCR from the positive samples in order to findout the condition and the rule of the mixed infection, and then put forward thesuggestion of prevention and control system, providing theoretical basis and guidancefor clinical diagnosis and treatment of mixed infection and regional prevention inwestern region of Henan province. Mainly include:1. The test and analysis results of PRRSV170pieces of suspected PRRS samples were detected by the RT-PCR to amplifyPRRSV, and observed the result with the agar gel electrophoresis. The detective resultshowed that102pieces of samples all were positive result of HP-PRRS lacking90base, and positive rate was60%. It indicated that the prevalence of HP-PRRS waspervasive in this region, and the accuracy of clinical diagnosis was relative highsynchronously over50%. 2. The test and analysis results of PRRSV with PCV2、CSFV、PRV about mixedinfectionThe pathogens such as PCV2, CSFV and PRV were detected from the102piecesof positive samples of PRRS. The results showed that the total mixed infection ratewas76.47%, the double mixed infection rate was47.06%(the double mixed infectionby PRRSV and PCV2reached to25.49%), the triple mixed infection rate was21.57%,the quadruple mixed infection rate was7.84%. These results demonstrated that theco-infections of PRRSV with other pathogens such as PCV2, CSFV and PRV werecommon in the western region of Henan province, including the double mixedinfection, the triple mixed infection and quadruple mixed infection. Especially, thedouble mixed infection by PRRSV and PCV2was the most serious.3. The difference of mixed infection with the spring and summer, and autumnand winter seasonThese samples were separated into two parts about spring and summer, andautumn and winter season. The results showed that in spring and summer, autumn andwinter season, the mixed infection rate was71.43%and87.50%respectively. Itdemonstrated that the mixed infection was more serious in the autumn and winter thanin the spring and summer. The results according to the contrast of different seven kindof mixed infection style about mixed infection demonstrated that whether they werethe double mixed infection, the triple mixed infection or the quadruple mixed infection,showed that autumn and winter season were more serious on the whole.4. The difference of mixed infection with different stages of swineThe results according to the different stages of swine showed that the mixedinfection rate was68.42%during suckling period,72.73%during nursing period and100%during fattening period. It demonstrated that the co-infections of PRRSV withother pathogens such as PCV2, CSFV and PRV were all existent from suckling tofattening period, and moreover, the degree of mixed infection was increased whenpathogenetic age was increscent.5. The difference of mixed infection from different sourceThe results which had been detected through the78suspected PRRS sampleshaving specific source indicated that the piglets bought from the outside were easy tohave mixed infection The total mixed infection rate was reach to100%, especially thequadruple mixed infection(PRRSV/CSFV/PCV2/PRV) was the worst. However, themixed infection rate of livestock propagated and raised by piglets was92.31%, and no quadruple mixed infection. So the piglets bought from the outside was more seriousthan livestock propagated and raised by piglets in mixed infection.Briefly, this study indicated that the co-infections of PRRSV with otherpathogens such as PPV, PRV and PCV2were common in the western region of Henanprovince，their mixed infection was complex and far-gone. Furthermore，the tip whichdone prevention of respiratory infectious diseases work well and especially chooseself-supportive method may be effective.