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PRV Eradication: By Dr. John Johnston
What’s working in Indiana is our people! This includes our state and federal veterinarians, our veterinary practitioners, our swine producers, our Swine Health Advisory Committee, our eleven member Board of Animal Health, and the staff of the swine division.
In our state we have an excellent working relationship between the state and federal agencies. For purposes of the Pseudorabies Eradication Program, the state is divided into eight geographic areas. Six of the areas are the responsibility of state field veterinarians, and two are under federal VMOs. Another VMO is assigned to work statewide in the pseudorabies program. The area veterinarian in charge, Dr. Francisco Collazo, and our state veterinarian, Dr. Bret Marsh, cooperate to provide a united front to keep Indiana moving along in the eradication effort.
The veterinary practitioners in the state are, as a group, very knowledgeable and capable in general herd health principles, including pseudorabies. In Indiana the private practitioner is the one performing the testing functions on fee-basis payment. Our state and federal veterinarians perform very little actual blood testing. This allows our field veterinarians to work more on epidemiology and herd cleanup plans.
Indiana producers, also, are realizing the necessity of cleanup as part of their herd health programs, both as a day to day part of their business, and in order to maintain trade relationships with other states and with other countries.
Here are some examples of our progress. In 1989 (Figure 1) we had 872 infected herds and 237 high risk vaccinated herds for a total of 1109 total quarantined herds.
In 1990 our feeder pig law went into effect. It required all feeder pig producers to test their herds annually. In 1992 our Down-the-Road Law required all swine herds to be tested.
Now we have only 287 quarantined herds in the state (Figure 2) and we feel that we are on target to meet the goal of eradication by the year 2000.
Our current status: Stage II Stage III
9600 herds in Indiana 2,321 herds (24%) 7,279 herds (75%) 480,000 sows in Indiana 179,000 sows (37%) 301,000 sows (63%) 287 quarantines 271 quarantines 16 quarantines Prevalence rate = 2.98% 11.7% 0.22%
We have 67 counties with no known infection and 25 with known infection.
As in most other states, once the differential vaccines and differential tests became available, the infection levels were more clearly understood and manageable. The combination of the differential tests and the testing requirements mentioned previously allowed Indiana to begin making progress toward eradication.
The graph (Figure 4) illustrates the number of quarantined herds in Indiana by quarter from 1981 through the first quarter of 1996, which just ended. Here we can see the herds quarantined for use of non-differential vaccine. Steady progress has been shown since mid-1992. The national graph (Figure 5) shows similar progress nationwide.
The surveillance method Indiana uses is the herd-basis test which is commonly called the "Down-the-Road Method." As I mentioned previously, the on-farm testing is performed by private practitioners. Each herd in the state must maintain status by a percentage test of the herd annually in our Stage II counties and every second year in Stage III counties.
Other methods of monitoring are used to identify herd infection in conjunction with herd surveillance. These include:
1. Change of ownership testing.
2. Qualified herd testing (we currently have 400 herds qualified.)
3. Exhibition testing.
4. Import retesting except on animals from higher status states or areas.
5. Circle testing (two mile circle around infected herds).
6. Slaugher tracebacks. Some states test animals origninating from Indiana and notify us of positives to trace to the herd of origin.
Any herd identified with pseudorabies must have a quarantine written by a state or federal veterinarian.
An epidemiology report is completed on each herd quarantine, the source of the infection is determined if possible.
A herd cleanup plan is developed by the producer, the veterinary practitioner, and the state or federal veterinarian as soon as possible following the quarantine.
Fee-basis funds are offered to the producers with infected herds. Federal and state money will pay for the practitioner's trip fee, and for blood testing in all quarantines or exposed herds. Also, state funds are available on a 50/50 vaccine cost share with the producer for use in pigs in herds with positive finishing floors. Herd cleanup plan is developed by the prodcucer , the veterinary practitioner, and the state or federal veterinarian as soon as possible following quarantine. Basis funds are offered to the producers with infected herds. State and federal funding for the eradication effort for at least the next two years seems to be good. However, we do not know how long the resources will hold out. Therefore, elimination of the disease from herds as soon as possible is imperative.
This is where the foresight of our Swine Health Advisory Committee and the dedication of our governing board have been important in how the Indiana eradication program works. The Advisory Committee has been proactive in developing the Indiana feeder pig law, our Down-the-Road surveillance law, the cost share vaccine fund and other innovations to keep the program moving. Our board has followed their lead and adopted those policies and rule changes to allow it to work.
In order to assure eradication of pseudorabies from Indiana by 2000, we have a set of proposed rules changes before our board now. These proposed changes have been passed by the Swine Health Advisory Committee and have been read and passed by the Board of Animal Health on first reading. A public hearing and second reading of the proposed changes will be held on April 25. We anticipate adoption of these changes which will become effective on July 1, 1996.
Proposed Rules Changes
2. Language clarifications
3. Adoption of Program Standards as state regulations.
4. Effective 7/1/96 for quarantines herds a. Test 95/10 (30/30) twice yearly or as per heard cleanup plan b. Vaccinate all swine as per herd cleanup plan 1) Breeding stock - twice yearly 2) Progency/Feeders - at least once in positive finishers Free-Basis funding and cost share vaccine available
6. Efficetive 7/1/98 for quarantines herds a. Contine test protocol - fee basis? b. Continue vaccination protocol - cost share? c. Circle vaccination evaluated for herds around infected herds d. Marketing/transportation protocols for the non-complying herd owner 1) vs-127 2) Sealed transport vehicle 3) Must have approved destination 4) Clean and disinfect The other people who make Indiana's program work are the Swine Division staff (Figure 7). We have four people making the Swine Division and the pseudorabies program work on a daily basis.
Our Program Coordinator is in charge of all infected herds and Validated/Qualified herds. The three other staff members cover the other functions with which we are charged. Those functions are:
1. Imports - permits, import quarantines, retests
2. Export/exhibition - health certificates, change of ownership testing
3. Herd monitoring - Down-the-Road surveillance, feeder pig herd surveillance
4. Slaughter and marketing tracebacks
Through the work of all of these people -- our state and federal veterinarians, our producers, veterinary practitioners, Swine Health Advisory Committee Members, Board of Animal Health members and our office staff, including the sound leadership of Dr. Bret March -- we are confident that we will be able to eradicate pseudorabies from Indiana by the year 2000.
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