Elimination of Arctic Variant Rabies in Red Foxes, Metropolitan Toronto

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Canada; Evelyn
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.356.4533

To control the Arctic variant of rabies virus in red foxes, 332,257 bait doses containing live, attenuated Evelyn-Rokitnicki-Abelseth rabies vaccine were distributed in greater metropolitan Toronto during 1989–1999. Human and pet contact with bait was minimal, and no adverse reactions to the vaccine were noted. Significantly fewer rabid foxes were found during the 17 years after fox baiting (5 cases during 1990–2006) than in the 17 years before (96 cases during 1973–1989). The last report of a rabid fox in metropolitan Toronto was in 1996 (reporting period through September 2006), which confirms that distributing oral rabies vaccine bait is a feasible tactic for the control of rabies in foxes in urban environments. The Arctic variant of rabies virus has been present in red fox (Vulpes vulpes) populations in Ontario, Canada, since the mid-1950s (1,2). During 1954–2006, more than 57,000 rabid animals were reported in Ontario, and, on average, 1,000–2,000 humans received rabies postexposure treatment (3,4). Before rabies control programs were implemented, red foxes accounted for ≈45 % of all rabies cases in Ontario (2,5). In metropolitan Toronto, rabies was cyclic from the 1960s to the 1980s; outbreaks in red foxes and striped skunks (Mephitis mephitis) occurred every 2 to 5 years (Figure 1). Methods Beginning in 1989, oral vaccination using bait that contained the live, attenuated, Evelyn-Rokitnicki-Abelseth (ERA) (6,7) strain of rabies virus was distributed in Ontario to control rabies in red foxes in rural and urban habitats (4,8–10). The bait matrix consisted of beef tallow