[Infectious agent detection in reproductive disorders in swine herds. Retrospective evaluation of diagnostic laboratory examinations].

OBJECTIVE

The detection rate of various viral and bacterial agents causing reproductive failure in sows was analysed.

MATERIAL AND

METHODS

Samples from abortion/uterus (n=714), sera from weak born piglets (n=317), cervical swabs (n=881) and urogenital organs from slaughtered sows (n=416) that had been submitted between January 2006 and June 2009 were included in this analysis. Various PCR assays were run to detect PRRSV, PCV2, PPV, Chlamydia spp. and Leptospira spp. Other bacterial agents were examined using standard cultural methods.

RESULTS

In material from abortion, detection rates of 14.7% for PCV2 and 6.8% for PRRSV EU genotype were revealed using PCR screening. The other agents were detected in single cases only (PPV 2.2%, PRRSV US genotype 1.8%, Chlamydia spp. 1.0%, Leptospira spp. 0.8%). Single PCR yielded a significantly higher detection rate for PCV2 than PCR screening. Comparing results from abortion/uterus and serum samples from weak born piglets, a significantly higher detection rate of PCV2 and PRRSV was found in sera. Bacteriological examination revealed bacterial agents in more than 75% of all cervical swabs. However, half of them had to be considered as contaminated due to the diversity of the isolated bacteria. Bacteriological testing of urogenital organs from slaughtered sows yielded positive results in 60% of all samples, with a remarkably lower proportion of contaminated samples of 7.4%.

CONCLUSION

It is assumed that 60-70% of all cases of reproductive failure are similarly not caused by primary infections. If PRRSV infection is suspected, examination of serum samples from weak born piglets is much better than the testing of foetuses or other material from abortion. Due to poor detection rates, the examination of foetuses/abortion material by screening PCR cannot be recommended. In the case of bacterial infections of the urogenital system, the cultural examination of organs from slaughtered sows is more often successful than the testing of cervical swabs.