Approach to management of suspected rabies exposures

Dear Dr. Casale,

In reference to Case 3 of my article, I have had several colleagues point out that as of August 2008 the guidelines for recommending rabies PEP in Ontario have changed with regard to individuals who wake up from sleep and find a bat in their room. This decision was based on research published by Dr. DeSerres of l’Institut National de Santé Publique du Québec, and further details can be found on the Ontario Ministry of Health and Long-Term Care website (http://www.health.gov.on.ca/english/providers/pub/disease/rabies_qa.html ). The province of British Columbia has also updated their rabies guidelines in a similar fashion.

While I was aware of the Ontario changes when submitting my article for publication, I chose not to include them when discussing case 3 as they were not consistent with the most recently published national Canadian guidelines (i.e. National Advisory Committee on Immunizations). Furthermore, other recognized international rabies PEP guidelines (e.g. Centres for Disease Control, World Health Organization) have yet to make such changes.

Given that management of potential rabies exposures to bats, as outlined in case 3 of my article, seems to be somewhat of a "grey" area, your point that each case needs to be assessed on an individual basis is extremely important. One should not interpret the recent guidelines change in Ontario to mean that individuals who wake up in a room and find a bat have no risk for rabies exposure. Given that bats are considered high risk for transmitting rabies, a proper risk assessment for direct exposure should still take place with the assistance of local public health experts. A key question to ask is whether the individual would likely wake up from sleep if s/he felt a sharp bite/scratch? If the answer is "yes", then the likelihood of direct exposure while sleeping is low. It is also important to consider whether the above likelihood would change under certain circumstances, such as if the individual in question was a child (e.g. unreliable historian), under the influence of alcohol or mentally challenged? A physical examination looking for bites/scratches should also be part of the assessment.

Finally, from a prevention standpoint, individuals in Canada who live in geographical areas known to have a high prevalence of bats should consider "bat-proofing" their homes to reduce their chance of exposure. There are many wildlife companies available that specialize in providing such services.

References:

1) Cooper K et al. Rabies in BC: A prophylaxis guidelines update. BC Medical Journal 2009; 51(2): 82-3.

2)  National Advisory Committee on Immunization, Rabies vaccine. Canadian immunization guide. 7th ed, Cat No HP40-3/2006E. Ottawa, ON: Public Health Agency of Canada; 2006. p. 285–97. Available from: www.phac- aspc.gc.ca/publicat/cig-gci/index-eng.php. Accessed 2009 Jan 21.

3) Centres for Disease Control (CDC) Clinician Outreach and Communication Activity (COCA). September 4, 2007: Human Rabies Prevention: Trouble Shooting Prophylaxis (http://emergency.cdc.gov/coca/confcall_archive.asp)