New Oral Rabies Vaccine (ORV) baiting strategy known as “pulse baiting” to address recent raccoon-variant rabies positive cases in Central Alabama


Coated sachet bait containing genetically-modified vaccinia virus to resemble rabies. Photo provided by Joanne Maki, Merial

Since intensive oral rabies vaccination (ORV) efforts were conducted in central Alabama in 2005, new rabies cases in raccoons and foxes have popped up in Elmore and Autauga counties, areas that were considered to be raccoon-rabies-free. The USDA is considering these positive cases as breaches‖ of the Alabama-Coosa river system, a natural, geographic barrier for the endemic occurrence of raccoon-variant rabies within Alabama.
As part of a nation-wide contingency action to halt new cases in previous rabies-free areas, USDA WS plans to use a newly-studied pulse baiting‖ strategy in early fall. Pulse baiting will involve aerially distributing oral rabies vaccines for raccoons and other wildlife by hand from helicopters at a rate of 8 vaccine baits per 13 seconds in habitat that is attractive to raccoons. The proposed pulse baiting area will encompass roughly 400 mi2 in Elmore, Autauga and Chilton counties and will include locations where positive cases have been detected as well as areas to the north and west.

Previous studies in the area have identified local raccoon population densities, and baiting rates have been adjusted based on those results. The timing and baiting rates of pulse baiting are also adjusted to increase bait uptake in the juvenile raccoon population that still travels with adults in family groups in the early fall. Coated sachet baits will be used in this strategy as they are easier for juveniles to puncture and ingest. In a 4-8 week span following the distribution of baits, biologists will capture raccoons within the bait zone, collect a blood sample and biological information, tag and release animals. Rabies titer levels will be examined to determine the percent of the population that received immunity from the vaccine.
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Report sick carnivores from yellow areas in map at above left to your local CHD or USDA WS @ 1-888-RABIES4


Graphic by Jordona Kirby, USDA APHIS WS

Graphic by Jordona Kirby, USDA APHIS WS