Emergency response to raccoon rabies introduction into Ontario

During 15 July to 4 October, 1999, rabies control programs were implemented with the objective being to contain the first three confirmed cases of rac coon rabies in Canada. The strategy, called point infection control (PIC) i nvolved the use of three tactics: population reduction (PR), trap-vaccinate -release (TVR) and oral rabies vaccination with baits (ORV), to control the spread of raccoon rabies. A total of 1,202 raccoons (Procyon lotor) and 33 7 skunks (Mephitis mephitis) were captured and euthanized using 24,719 trap -nights in the three PR zones around the location of the three rabies cases , near Brockville, Ontario. That represented an 83% to 91% reduction in the raccoon populations in an approximate 225 km(2) area around the three rabi es cases. Raccoon density in the PR zones declined from 5.1-7.1/km(2) to 0. 6-1.1/km(2) following control. All tested specimens were negative for rabie s by the fluorescent antibody test (FAT). In addition, 1,759 raccoons and 3 77 skunks were intramuscularly vaccinated against rabies and released using 27,956 trap-nights in an approximate 485 km(2) TVR zone implemented outsid e of the PR zones. A total of 856 cats from both PR and TVR areas were also captured, vaccinated and released. Cost for the three PIC operations was $ 363,000.00 Cdn or about $500.00 Cdn/km(2) To further contain the outbreak, about 81,300 baits containing Raboral (R) V-RC oral rabies vaccine were aer ially distributed on 8 and 27 September 1999, to create an 8 to 15 km wide buffer zone (1,200 km(2) area) of vaccinated raccoons immediately beyond th e PR and TVR zones. This was the first time that V-RG was used in Canada to orally vaccinate free ranging raccoons against rabies. Baiting costs were $241,000.00 Cdn or about $200.00 Cdn/km(2) including post baiting assessmen t costs. As of 31 August, 2000, thirty-five additional cases (38 in total) of raccoon rabies have occurred in the control and vaccination zones. This number is far below the level of rabies prevalence in USA jurisdictions whe re raccoon rabies was epizootic. In the future, PIC methodologies will cont inue to be used in Ontario to contain isolated cases of raccoon rabies.