Finding infected herds

• Required testing for movement of breeding swine

• Monitoring program:

1988 - 51 county Northern zone herds selling feeder pigs

1990 - statewide monitoring of herds selling feeder pigs

1991 - All herds must monitor

• Surveillance: circle testing, traceback testing, slaughter testing

• Number of Infected Herds (See fig. 1):

November 1992 - the number of infected herds peaked at 903, as of April 1, 1996, there are 281 quarantined premises (fig. 2)

Clean up of Infected Herds

• Since 1992, clean up of infected herds has surpassed the number of newly infected herds

• November 1994 - rules in place that require periodic testing in all quarantined herds to assess clean up progress and annual renewal of herd clean up plans

Progress of Stage Status

• 1991 - 51 counties (Northern zone) granted Stage III status

• 1993 - 15 additional counties granted Stage III status

• 1995 - 9 additional counties granted Stage III status

• Currently 75 countries in Stage III status 12 in Stage II (fig. 2)

Free of PRV by 2000

• Is it achievable - projection is PRV free by late 1998 if clean up continues at the present rate

• Challenges:

continued virus calculation in herds with long standing quarantines Rapid clean up of newly infected herds Why the PRV eradication program has worked in Minnesota

• Changes in management practices such as All In/All Out, early weaning, offsite production and improved biosecurity

• Vaccination and accompanying differential tests

• Rule changes and progression of countries to Stage III status restrict movement of quarantined swine

• "Cooperation" the Minnesota Board of Animal Health has received excellent cooperation from all facets of the swine industry with a special thanks to the producers, marketing people, and our practitioners

Figure 1

Figure 2