Rabies & Animal Bites Information for Health Professionals

Rabies is a rare viral central nervous system infection most often transmitted to humans through the bite of an infected mammal. Rabies occurs worldwide, although most human deaths occur in Asia and Africa. The disease occurs very rarely in Canada. Between 1924 and 2009, 24 people in six provinces died of rabies; the last human case acquired in Ontario was in 1967.

Rabies post-exposure prophylaxis should be given only if indicated by an evidence-based assessment of risk. Pre-exposure immunization and post-exposure prophylaxis are highly effective in preventing rabies.

 

A five-Ws approach can be used to assess whether or not post-exposure prophylaxis is indicated for your patient:

Where did the exposure occur?

  • In Toronto, the risk of being exposed to a terrestrial animal with rabies is low.
    • The number of animal cases of rabies has been reduced significantly in Ontario since the raccoon rabies control program began in 1989.
    • The most recent terrestrial wildlife with rabies in Toronto was in 1997. In 2008, a puppy with rabies was imported from rural Ontario to Toronto.
    • Cases of raccoon strain rabies were confirmed in raccoons and skunks in Hamilton, Haldimand-Norfolk and Niagara since 2015. The number of new cases of animal rabies associated with this outbreak has been decreasing compared to 2016.
  • Bats infected with rabies can be found in the Greater Toronto Area and the rest of Canada.
  • In countries or areas at risk, the risk of being exposed to an animal with rabies can be much higher. There are also many countries recognized as rabies-free for domestic cats and dogs.

What type of animal was involved?

  • Only mammals can be infected with rabies.
  • In Asia and Africa, dogs are the main carriers of rabies.
  • In Canada, wild animals (e.g., raccoons, skunks, foxes, bats) have a higher risk of carrying the rabies virus than domestic animals (e.g., dogs, cats, ferrets).
  • An estimated one to four per cent of bats in Canada may be infected with rabies.
  • Small rodents (e.g., rats, mice and squirrels), are rarely found to be carrying the rabies virus. Exposures to these animals require post-exposure prophylaxis in exceptional circumstances only, such as highly unusual behaviour.
  • Refer to the Canadian Immunization Guide summary table by animal.

Why did the exposure occur?

  • Provoked exposures include human behaviours such as petting, feeding, trying to capture, trying to assist an injured animal, or invading an animal’s space.
  • Unprovoked attacks are more likely to indicate that the animal may have rabies.

Who is the animal’s owner?

  • For exposures involving domestic animals, Toronto Public Health can contact the animal owner to observe its health and determine its immunization status. This information could potentially allow your patient to avoid unnecessary treatment and visits to the health care provider.
  • Animal testing for rabies may be done in rare circumstances, such as illness or death of the animal during the observation period.
  • If an animal cannot be observed, then the rest of the risk assessment should guide post-exposure prophylaxis decision-making.

Wound evaluation and care

  • Bites are the most common mode of transmission of the rabies virus.
  • Bites on the face, neck or hand are considered higher-risk exposures due to the density of nerve endings in these areas. Bites to the face and neck are also much closer to the central nervous system (CNS), making time to CNS infection much shorter.
  • More severe or multiple bites are also a higher risk because they provide more opportunity for transmission.
  • Non-bite exposures (e.g., scratches) from mammals rarely result in transmission, unless there is salivary contact on broken skin or mucous membrane.
  • Direct contact with a bat (bat touching the skin of the person or bat salivary exposure into a break in the skin or onto a mucous membrane) are higher risk and require post-exposure prophylaxis and/or testing of the bat. Refer to Rabies Guidance for Health Care Providers, Public Health Ontario for further information.
  • Petting a rabid animal or handling its blood, urine or feces are not considered exposures, as the virus is transmitted through saliva. These exposures would not require post-exposure prophylaxis.
  • All wounds should be flushed and cleaned with soap and water for approximately 15 minutes.
  • Avoid suturing the wound if possible.
  • Tetanus prophylaxis and antibiotics should be given as appropriate.

Contact Toronto Public Health for assistance with the risk assessment.

If indicated based on the risk assessment, initiate post-exposure prophylaxis as soon as possible, regardless of how long ago the exposure occurred. (See Contact Toronto Public Health at the bottom of this page.)

Post-exposure prophylaxis of persons not previously immunized against rabies

Day Treatment
Day-0
  • Rabies vaccine (brand names: Imovax® Rabies, RabAvert®)
    • Administer one dose (1 mL) IM in the deltoid.
    • In infants <12 months, vaccine should be given IM in the anterolateral thigh.
  • Rabies immune globulin (brand names: Imogam® Rabies or Hyperrab®)
    • Administer 20 IU per kg body weight for all age groups. Each vial contains 150 IU. You will need to administer multiple vials of immune globulin on day-0.
    • Using a different syringe and needle than for the vaccine, infiltrate as much immune globulin as anatomically possible into and around the wound(s), similar to freezing a wound.
    • Any remaining volume of immune globulin should be injected IM, using a new needle, at one or more site(s) distant from the site of vaccine administration (e.g., gluteal area, anterolateral thigh).
    • If there are multiple or extensive wounds present, immune globulin can be diluted two to three-fold in normal saline (0.9 per cent sodium chloride) to allow thorough infiltration of all the wounds.
Day-3 Administer one dose of rabies vaccine IM in the deltoid.
Day-7 Administer one dose of rabies vaccine IM in the deltoid.
Day-14 Administer one dose of rabies vaccine IM in the deltoid.
Day-28 Administer a fifth dose of rabies vaccine IM in the deltoid, only if the patient is immunocompromised or taking immunosuppressants or antimalarial medication. Antibody serology seven to 14 days after completion of the vaccine series is recommended only for people whose immune response may be reduced by illness or medication.

Post-exposure prophylaxis of persons who previously completed a full course of rabies immunization

Day Treatment
Day-0
  • Rabies vaccine (brand names: Imovax® Rabies, RabAvert®)
    • Administer one dose (1 mL) IM in the deltoid.
    • In infants <12 months, vaccine should be given IM in the anterolateral thigh.
  • Rabies immune globulin should not be given to persons who have previously received appropriate rabies vaccinations.
Day-3 Administer one dose of rabies vaccine IM in the deltoid.

Vaccine schedule deviations

Vaccination schedules for post-exposure prophylaxis should be adhered to as closely as possible. It is essential that all doses be received. Doses should not be given early to allow for sufficient immune response between doses.

If a dose of vaccine is delayed, it should be given as soon as possible and the schedule resumed, preserving the spacing between intervals for subsequent doses. If there has been a significant deviation from the recommended vaccination schedule, immunity can be assessed with serology testing seven to 14 days after the last vaccine dose.

Contraindications and precautions

There are no contraindications for rabies vaccine or RabIg after significant exposure to a proven rabid animal; however, care should be taken if PEP is to be administered to persons who are hypersensitive to the products or to any ingredient in the formulation or component of the container, including the following potential allergens:

  • Imovax® Rabies vaccine: neomycin, phenol red
  • RabAvert® vaccine: amphotericin B, chick protein, chlortetracycline, neomycin, polygeline (gelatin)
  • Imogam® Rabies immune globulin: latex in vial stopper

Imovax® Rabies vaccine is preferred for vaccinees with a history of hypersensitivity reactions to eggs or egg products. RabAvert® vaccine should only be administered to these persons if Imovax® rabies is not available and with strict medical monitoring.

Pregnancy and breastfeeding

Pregnancy and breastfeeding are not contraindications to post-exposure rabies prophylaxis.

Common adverse reactions

Common adverse reactions include injection site reactions, such as pain, erythema, swelling, and itching. Serious side effects are rare.

PEP initiated outside of Canada

  • PEP given outside of Canada may include products not approved in Canada.
  • Review available documentation from the patient, including product name, dosage, and route of administration.
  • The following vaccines meet World Health Organization’s (WHO) safety, potency and efficacy requirements:
    • Verorab™ (a purified Vero cell rabies vaccine)
    • Rabipur® (a PCECV vaccine)
  • If a WHO-approved vaccine series was started while overseas, the series can be completed with a rabies vaccine approved in Canada. Serological testing is recommended seven to 14 days after completing the series.
  • If the vaccine or schedule is not WHO-approved, consider re-initiating the series using rabies vaccine approved in Canada.
  • If the vaccine series was given intradermally and not completed, re-initiate the series using rabies vaccine approved in Canada.
  • If no rabies immune globulin has been administered while overseas, it can be provided in Canada up to seven days after the first dose of dose of WHO or Health Canada-approved vaccine.

Immunization records

Health care providers should record all vaccine doses and immune globulin administered to an individual in two places:

  • the personal immunization record held by the vaccine recipient, or his or her parent or guardian AND
  • the record maintained by the health care provider who administered the vaccine.

For more information

Transmission

Rabies is spread to humans when the virus in the saliva of an infected animal enters through broken skin, the mucous membranes or the respiratory tract. Bites from an infected animal are the main route of exposure. Transmission also occurs through transplantation of organs from infected persons.

Incubation period

The virus gains access to the central nervous system through peripheral nerves. The usual incubation period is proportional to the distance from the portal of entry to the brain and may vary from several days to years (most commonly three to eight weeks).

Signs and symptoms

Symptomatic rabies is an almost always fatal viral infection of the central nervous system.  Early symptoms of rabies may include:

  • headache
  • malaise
  • fever
  • fatigue
  • discomfort or pain at the exposure site (i.e., the site where the person was bitten)

Symptoms progress quickly once the central nervous system is attacked, and the illness generally presents in one of two ways:

  • The more common, agitated (furious) form presents with the classic symptoms of hydrophobia and aerophobia (severe laryngeal or diaphragmatic spasms and a sensation of choking when attempting to drink or when air is blown in the face) with a rapidly progressing encephalitis and death.
  • The paralytic form of the disease manifests in progressive flaccid paralysis, has a more protracted course, and is more difficult to diagnose.

Pre-exposure prophylaxis

Pre-exposure prophylaxis is recommended for people at high risk of close contact with rabid animals or the rabies virus, including:

  • people with occupational exposure to animals, such as veterinarians and veterinary staff, animal control and wildlife workers
  • laboratory workers handling the rabies virus
  • certain travellers to countries or areas at risk.
  • hunters and trappers in areas with confirmed rabies
  • people who explore caves (spelunkers)

Pre-exposure immunization consists of three 1 mL IM doses in the deltoid of rabies vaccine (brand names: Imovax® Rabies, RabAvert®) given on day-0, day-7 and any time between days 21 to 28.

Rabies Vaccine and Rabies Immune Globulin Fact Sheet for Patients

Protection measures

The following measures can be taken to protect people and their pets from rabies:

  • Pet dogs and cats must be vaccinated against rabies. This is required under Ontario legislation, Health Protection and Promotion Act, Regulation 567
  • Make sure that pet dogs are supervised. They should not run loose in public spaces, unless in off-leash parks
  • Stay away from all wild animals, especially if they appear tame, injured or sick
  • Wild animals that show abnormal or sick behaviour should be reported to 3-1-1
  • Wildlife-proof the home and yard. Store garbage bins inside a garage/basement until the morning of pick-up.

Physicians have a duty to report animal-to-human exposures that in their opinion may result in the transmission of rabies under Regulation 557, Section 2(1), of the Health Promotion and Protection Act. Toronto Public Health can assist physicians with risk assessments, manage potentially rabid animals, and provide post-exposure prophylaxis (PEP) to requesting physicians.

To report an animal exposure to Toronto Public Health:

  • During business hours (8:30 a.m. – 4:30 p.m.), call Toronto Health Connection at 416-338-7600 or fax the Animal Exposure Report to 416-696-4297.
  • After business hours, fax the Animal Exposure Report to 416-696-4297 or call 3-1-1 only if you need to speak to staff after hours.

Order post-exposure prophylaxis

  • Speak with a TPH staff member by telephone to discuss the risk assessment and to order post-exposure prophylaxis:
    • Call Toronto Health Connection at 416-338-7600 on weekdays between 8:30 a.m. and 4:30 p.m.
    • Call 3-1-1 at any other time
  • The Animal Exposure Report does not need to be completed or faxed when PEP is ordered or the exposure is reported by telephone.

Report a suspected or confirmed case of rabies in a human

Physicians have a duty to report suspected or confirmed human cases of rabies immediately to the Medical Officer of Health, under the Health Promotion and Protection Act.