Since the mid-1990s, Canada and the United States have recommended the testing of bats or the use of rabies postexposure prophylaxis after discovery of a bat in the same room as a child, a cognitively impaired person or a sleeping person. 1–3 These recommendations were based on case reports from the United States in which a strain of bat rabies virus was isolated from people who had had no obvious exposure to a bat. 2
Canadian researchers have since determined that rabies is extremely rare when there is no obvious contact with a bat. A case of rabies related to bedroom exposure (the presence of a bat in the room of a sleeping individual with no recognized physical contact with the bat) has been estimated to occur in Canada once every 84 years. 4 This rate is very low even though bedroom exposures to bats occur fairly often (about 10 per 10 000 people annually) and are reported for post -exposure management less than 5% of the time. 5 The researchers estimated that more than 2.6 million people would need to be treated to prevent 1 case of rabies related to a bedroom exposure.
The National Advisory Committee on Immunization is therefore now recommending the testing of bats or the use of rabies postexposure prophylaxis only when both of the following conditions apply:
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There has been direct contact with a bat (i.e., the bat has touched or landed on a person) and
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A bite or scratch from a bat or exposure of a wound or mucous membranes to saliva from a bat cannot be ruled out.
A full discussion of these changes is available in the committee’s updated recommendations on managing bat exposures to prevent human rabies. 6 Clinicians can also consult with their local public health office for assistance in determining the risk associated with a particular exposure to a bat.
Footnotes
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Competing interests: None declared.
This article has been peer reviewed.
Previously published at www.cmaj.ca
REFERENCES
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