Tag: negative status

PRRS incidence in status 4 sow farms

This is our Friday rubric: every week a new Science Page from the Bob Morrison’s Swine Health Monitoring Project. The previous editions of the science page are available on our website.

This week, the MSHMP team updates a valuable statistical parameter: the PRRS incidence in status 4 status 4 sow farms. As a reminder, status 4 farms are defined as negative for PRRS in both exposure and shedding status.

Key Points

  • In the last 13 years, on average 9.3% (Range 3.2% – 20.3%) of status 4 farms have had a PRRS outbreak, with an apparent cyclical peak at around 10% every 2-3 years.
  • The cumulative incidence of the current MSHMP year (July 2020 to May 2021) for status 4 farms is 9.9%.
  • PRRS incidence in status 4 farms during the current MSHMP season is not higher than the ones observed in the previous MSHMP seasons.
Continue reading “PRRS incidence in status 4 sow farms”

Comparison of PRRS incidence rate in status IV breeding herds during 2009-2019

This post is from the MSHMP team looking at status IV farms and their PRRS incidence between the years 2009 and 2019. Quick reminder, in 2011, Holtkamp et al. defined status IV farms as PRRS-negative per their shedding and exposure status.

Key points

  • PRRS incidence rate in status IV farms varied significantly from 2009 to 2019.
  • The incidence rate in status IV farms during 2019 was one of the lowest on record and comparable to the one observed in 2013 and 2014; the years of the PED epidemic in the US.
  • PRRS incidence in status IV farms during 2019 was significantly lower than the one of 2015 and 2016 and marginally non-significant lower (p=0.07) than the one of 2018.
Continue reading “Comparison of PRRS incidence rate in status IV breeding herds during 2009-2019”