COMPONENTS OF DEMONSTRATING PROGRESS IN PSEUDORABIES HERD CLEANUP

The ability to measure progress in pseudorabies herd cleanup is vital to eradicating the disease by the year 2000. The purpose of this presentation is to demonstrate and explain components used to measure herd clean up in North Carolina. The three components that will be addressed are: (1) pseudorabies virus circulation; (2) pseudorabies positive vaccinated blocks; and (3) pseudorabies quarantined sow farm report cards. These components target swine herds that need attention and allow epidemiologists, veterinary medical officers and swine producers to focus their concern to problem herds and areas. Page 19 of the State/Federal Industry Program Standards indicates that in order for a Stage III area to retain status it must "demonstrate progress in herd cleanup consistent with the goal of eradication by the year 2000 with (a) herd clean up plan written within 30 days of quarantine and (b) all quarantine herds having at least a semiannual test of 95/10 with a herd plan review as necessary". Page 8 of the definition of a state pseudorabies committee includes "reviewing the state area pseudorabies eradication program and making recommendations to the state and federal animal health officials and as appropriate, consulting with state officials in the areas of progress through the program stages".

North Carolina is shifting from on-farm finishing floor surveillance in Sampson and Duplin Counties to first point testing surveillance (not to be confused with changing sow herd testing) either in a market that is handling light top hogs or at slaughter facilities. This will provide us with the necessary information to identify newly infected finishing herds. The Pseudorabies Virus Circulation map identifies herds circulating virus, shows progress, and provides vaccination information. Producers have agreed to vaccinate all swine within 1 mile around herds identified as circulating virus.

In the area of finishing swine, North Carolina has created pseudorabies positive vaccinated blocks as areas for producers to move quarantined finishing animals and vaccinate them in a cooperative effort to reduce the virus circulation load within Sampson and Duplin Counties, North Carolina. The enclosed map illustrates that as producers have made progress in eliminating the need for quarantined finishing spaces, they have been rewarded by the reduction in the number of positive vaccinated blocks. The producers have asked regulatory officials to monitor all producers’ utilization of vaccine on finishing floors in these blocks in an attempt to communicate to one another the level of responsibility that each producer is demonstrating to complete this program.

In order for North Carolina to make progress in the pseudorabies program, the state pseudorabies committee consisting of pork producers requested regulatory officials to develop a report card for each sow herd under quarantine for pseudorabies which would identify tangibly the components of whether a herd was progressing towards pseudorabies removal. This was done for all sow herds in the state. The overall objective was to stop virus circulation in sow herds and finishing floors as well as to prevent further circulation of virus in both Stage II and Stage III areas. The development of tangible components which could be communicated to all producers in a similar manner, such as the score card utilized by the Livestock Conservation Institute, which shows whether states are making progress, is considered an essential element of the program. North Carolina felt that with a score card, producers in both Stage II and Stage III areas would have the information necessary to encourage themselves and their neighbors to make progress consistent with the goal of eradication in the year 2000.

The pseudorabies quarantined sow farm score card carries an optimal score and lists the quarantined sow herds in order for those with the highest score to the lowest score. The progress report assigns individual scores to a herd based on (1) culling pressure being practiced in the herd; 2) numeric score of a standard biosecurity checklist conducted on the farm; 3) adequate vaccination occurring on the farm for both sows and finishing animals, including the proper handling and utilization of the vaccine; 4) whether the herd is circulating virus; 5) a comprehensive herd plan written within 30 days and whether it is updated upon request semiannually; 6) goal date with the shortest time from the date of quarantine; and 7) herd conducting semiannual testing in accordance with the national program standards.

The score sheets are reviewed by the State Pseudorabies Swine Committee and distributed to producers. The area epidemiologist and the Veterinary Medical Officers utilize the score sheet to target herds needing further emphasis.