ABSTRACT:During August 2006 and 2007, baits containing oral rabies vaccine, live adenovirus vector, known as ONRABH, were aerially distributed in SW Ontario, Canada. Bait acceptance during 2006 was 62 and 74% in raccoons (Procyon lotor) in areas baited at 150 baits/km 2 and 75 and 77% in plots baited at 300 baits/km 2 . During 2007, bait acceptance for raccoons ranged between 59% and 80%, and 83% and 87%, in areas baited at 75 and 400 baits/km 2 , respectively. Bait acceptance by skunks varied among plots (5-24%). Rabies virus-specific seroconversion during 2006 averaged 66 and 81% in raccoons in areas baited at 150 and 300 baits/km 2 , respectively. During 2007, seroconversion by raccoons was 76 and 84% in areas baited at 75 and 400 baits/km 2 , respectively. Seroconversion by skunks varied among plots (17-51%). Vaccine efficacy, as judged by the percentage of animals that consumed a bait and seroconverted, averaged 79 and 87% during 2006 for raccoons in areas baited at 150 and 300 baits/km 2 , respectively, and 81 and 90% in areas baited during 2007 at 75 and 400 baits/km 2 , respectively. Because tetracycline marking was poor in skunks, an estimate of vaccine efficacy was not possible. Aerial distribution of ONRABH vaccine baits seems to be a feasible tactic for controlling rabies in skunks and raccoons.

During 1999-2003, 127 cases of raccoon variant rabies were reported in raccoons (Procyon lotor) and striped skunks (Mephitis mephitis) in Ontario, Canada. Raccoons accounted for 98% (125/127) of the reported cases with behaviors/conditions including aggression, fighting with dogs, ataxia, vocalizations, appearance of being sick, and the presence of porcupine (Erethizon dorsatum) quills. Seventy-eight percent of the rabid raccoons were adults. Juveniles were underrepresented (22%) compared with the adult/juvenile ratios found in nonrabid Ontario raccoon populations. Of the known aged raccoons, 83% were < or = 3 yr of age, and 22% of the rabid adult female raccoons had evidence of having had a litter during the year in which they were found to be rabid. The majority of rabid raccoons were reported during the fall, winter, and spring, suggesting a relationship between raccoon behavioral activities such as denning and breeding and the timing of rabies outbreaks. Multiple cases of raccoon rabies occurred at several barns, suggesting that those structures serve as focal points of rabies transmission as a result of denning activities. Movements of five rabid raccoons (range 1,564-4,143 m) were not different from movements of nonrabid raccoons in Ontario. Sixty-six percent of the rabid animals were submitted by government staff, stressing the importance of those agencies in rabies control and surveillance operations. Increased knowledge of the behaviors of rabid raccoons should assist in the development of management strategies for rabies.

ABSTRACT:Proactive and reactive tactics have been utilized in Ontario, Canada, to prevent raccoon rabies from becoming established. A total of 96,621 raccoons (Procyon lotor) and 7,967 striped skunks (Mephitis mephitis) were live captured using 1,221,044 trap nights, vaccinated against rabies by injection, and released, during proactive Trap-Vaccinate-Release (TVR) programs in southern Ontario during 1994-2007. During those years, on average, 43% to 83% of the raccoon populations were vaccinated against rabies. In addition, 20,129 raccoons and 2,735 skunks were vaccinated against rabies, and 8,311 raccoons and 1,449 skunks were euthanized, using 576,359 trap nights, during reactive Point Infection Control (PIC) operations in eastern Ontario during 1999-2005. A significant correlation was detected between trapping effort and the percentage of the raccoon population that was vaccinated. Between 1999 and 2007, 132 cases of raccoon variant rabies (130 raccoons, two striped skunks) were reported in eastern Ontario. The last case occurred on 23 September 2005 with Ontario being free of reported raccoon rabies to 10 November 2008, proving that TVR and PIC are effective tactics for the control of this disease.