title: Bat rabies in the United States and Canada from 1950 through 2007: human cases with and without bat contact.
abstract: BACKGROUND
  Since the 1980s, rare cases of rabies in humans in Canada and the United States have been almost exclusively caused by the bat-variant virus.
  
  
  METHODS
  We reviewed indigenously acquired cases of bat-variant rabies in humans in Canada and the United States from 1950 through 2007.
  
  
  RESULTS
  Of 61 cases identified, 5 occurred after organ transplantation and were excluded from further analysis. A bite was reported by 22 (39%) of the case patients, 9 (16%) had a direct contact (i.e., were touched by a bat) but no history of a bite, 6 (11%) found bats in their home (2 [4%] in the room where they slept) but reported no direct contact, and 19 (34%) reported no history of bat exposure whatsoever. With the exception of California (8 cases) and Texas (7 cases), no state or province had >3 cases. Of the case patients, 76% were men, and 40% were 10-29 years of age. The median incubation period was 7 weeks (<10 weeks in 72% of cases). The incidence of bat-variant rabies cases increased from 2.2 per billion person-years in 1950-1989 to 6.7 per billion person-years in 1990-2007. Of 36 case patients with bat rabies described since 1990, 16 had no history of direct bat contact; 2 (13%) of the 16 would have qualified for rabies postexposure prophylaxis on the basis of exposure criteria expanded in 1995 to include bats that were in the same room as a sleeping person. The incidence of rabies for this type of exposure was 0.6 cases per billion person-years.
  
  
  CONCLUSIONS
  The true preventable proportion of cases and the number needed to treat with rabies postexposure prophylaxis to prevent 1 case would be useful information to inform the current guidelines.
authors.affiliation: Institut national de santé publique du Québec, Canada. gaston.deserres@ssss.gouv.qc.ca
authors.forename: Gaston
authors.initials: G
authors.lastname: De Serres
authors.forename: Frédéric
authors.initials: F
authors.lastname: Dallaire
authors.forename: Mathieu
authors.initials: M
authors.lastname: Côte
authors.forename: Danuta M
authors.initials: DM
authors.lastname: Skowronski
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002170:Canada / Q000453:epidemiology; D002648:Child; D002685:Chiroptera / Q000821:virology*; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D011818:Rabies / Q000453:epidemiology* / Q000635:transmission; D011820:Rabies virus / Q000302:isolation & purification; D014481:United States / Q000453:epidemiology