Occupations identified as high risk for rabies exposure and infection include veterinarians, animal control workers, rabies diagnostic lab workers, spelunkers exploring caves, bat biologists and other wildlife biologists, pest control workers, and workers traveling to countries endemic for canine-mediated rabies. While transmission to health care workers caring for a patient infected with rabies has not been documented, theoretically transmission could occur through direct contact of broken skin or mucosa with saliva, tears, oropharyngeal secretions, cerebrospinal fluid, or neural tissue of an infected individual. Rabies is a reportable disease under the Canada Food Inspection Agency (CFIA) Health of Animals Act.[1]

Causes

Rabies is a rare zoonotic disease caused by a Lyssavirus of the Rhabdoviridae family. In Canada, the disease is usually found in wild animals such as raccoons, skunks, bats, and foxes. Domesticated animals can become infected if they are bitten by an animal with rabies or come in contact with its saliva. Canine rabies remains endemic in many countries. Globally, dog bites provide the greatest risk of rabies transmission.[2-5] In BC, bats are the only known reservoirs for the rabies virus.[2]

The rabies virus is carried in the saliva and neural tissue of an infected animal and can be transmitted to humans via the animal’s bite or scratch, or through an individual’s open wounds or mucus membranes. While very rare, transmission via nonbite routes, such as airborne transmission from bat secretions[6] or direct human-to-human transmission through organ transplants[7] has been reported.

Disease progression

The incubation period is usually 3 to 8 weeks, although rarely can be as short as a few days to as long as several years.[2] After an initial period of nonspecific symptoms such as fever, malaise, or anxiety, frank neurological signs ranging from hyperactivity (encephalitis) to paralysis appear before the person lapses into a coma. Death typically occurs within 10 days from the onset of symptoms.[2]

Prevention

For workers in occupations that are high risk for rabies infection, pre-exposure prophylaxis with rabies vaccine is recommended, followed by a booster dose in the event of exposure.[2,6]

For health care workers, routine precautions, including wearing gowns, goggles, masks, and gloves, are recommended when providing care to persons suspected of having clinical rabies.[8] In the event of an exposure, public health officials follow specific criteria to identify high-risk contacts and provide postexposure prophylaxis.[2,3]

Workers should seek immediate medical attention if they suspect they have been exposed to rabies. In BC, any worker who has had direct contact with a bat should seek medical attention, and the attending physician should call the local public health authority for guidance. Public health will conduct a risk assessment to determine whether rabies postexposure prophylaxis is indicated.

Treatment

Postexposure prophylaxis for rabies includes thorough wound washing, a series of rabies vaccines, and where indicated, rabies immunoglobulin (RIG). Given promptly,[2] rabies postexposure prophylaxis is effective.[3]

When a worker is exposed to a bite or scratch of an infected source, rabies immunoglobulin is used to infiltrate the wound, or to infiltrate the exposed area when a bite or scratch cannot be ruled out. BC Centre for Disease Control has released new interim guidelines on postexposure prophylaxis and rabies immunoglobulin.[2,9] Tetanus-diphtheria vaccine should also be updated as required.

If your patient suspects they have been exposed to rabies at work, encourage them to file a claim with WorkSafeBC. Providing all the relevant clinical information on a Form 8/11 is important to help your patient with their claim.

For assistance

If you have questions about a workplace rabies exposure or claim, please contact a medical advisor in Occupational Disease Services at 604 231-8842 or in your nearest WorkSafeBC office, or call the Medical Advisor Hotline at 1 855 476-3049.
—Geetha Raghukumar, MBBS, DLSHTM, MSc, CIC, CCFP, FRCPC
WorkSafeBC Medical Specialist, Occupational Disease Services
—Olivia Sampson, MD, CCFP, MPH, RCPSC
WorkSafeBC Manager of Clinical Services

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This article is the opinion of WorkSafeBC and has not been peer reviewed by the BCMJ Editorial Board.

References

1.    Canada Food Inspection Agency. Rabies in Canada. Accessed 13 September 2019. www.inspection.gc.ca/animals/terrestrial-animals/diseases/reportable/rabies/rabies-in-canada/eng/1356156989919/1356157139999.

2.    BC Centre for Disease Control. Rabies. Accessed 13 September 2019. www.bccdc.ca/resource-gallery/Documents/Guidelines%20and%20Forms/Guidelines%20and%20Manuals/Epid/CD%20Manual/Chapter%201%20-%20CDC/BCRabiesGuidelines.pdf.

3.    World Health Organization. Rabies. Accessed 13 September 2019. www.who.int/news-room/fact-sheets/detail/rabies.

4.    Fooks AR, Cliquet F, Finke, S, et al. Rabies. Nat Rev Dis Primers 3, 17092 (2017).

5.    Murphy J, Sifri C, Pruitt R, et al. Human Rabies – Virginia, 2017. MMWR Morb Mortal Wkly Rep 2019;67:1410-1414.

6.    WorkSafeBC. Rabies. Accessed 13 September 2019. www.worksafebc.com/en/health-safety/injuries-diseases/infectious-diseases/types/rabies.  

7.    Vora NM, Basavaraju SV, Feldman KA, et al. Raccoon rabies virus variant transmission through solid organ transplantation. JAMA 2013;310:398-407.

8.    Provincial Infection Control Network of British Columbia. Routine practices and additional precautions for preventing the transmission of infection in healthcare settings. PHAC 2013. P.117. www.picnet.ca/wp-content/uploads/PHAC_Routine_Practices_and_Additional_Precautions_2013.pdf.  

9.    BC Centre for Disease Control. Interim direction for the use of rabies vaccine for post exposure prophylaxis in BC. Accessed 13 September 2019. www.bccdc.ca/resource-gallery/Documents/Guidelines%20and%20Forms/Guidelines%20and%20Manuals/Epid/CD%20Manual/Chapter%201%20-%20CDC/InterimRabiesVaccineRPEPGuidelines.pdf.