Management of Bites to Humans
Animal Bites and Rabies Risk: A Guide for Health Professionals
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Consultations on animal bites and rabies risk
Evaluation of the patient following animal bites
Assessment of the need for rabies post-exposure prophylaxis
Factors to consider when determining need for PEP
- Available 24/7 at 651-201-5414 for healthcare providers, public health professionals, veterinarians, and law enforcement.
- Available to the public Monday-Friday, 8:30 a.m. to 4:30 p.m. at 651-201-5414.
- Please do not call the MDH Public Health Laboratory.
- For questions regarding animals that have been bitten by a suspect rabid animal in which there is no human exposure, please contact the Board of Animal Health (BAH) at 651-201-6808.
- Wash the wound well with soap and running water.
- Assess the need for tetanus vaccination booster.
- Assess the need for antibiotics.
- Assess the need for rabies post-exposure prophylaxis (PEP).
- Is this a species that we are concerned about?
- Was there a bite or saliva exposure to a mucous membrane? Is the animal available for 10 days of observation or testing?
Type of exposure
- Bite exposures: Consultation with a healthcare provider is recommended anytime a bite wound breaks the skin. Considerations include wound cleaning, tetanus vaccination, the need for antibiotics, and whether or not rabies post-exposure prophylaxis (PEP) is indicated.
- Non-bite exposures: Non-bite exposures include saliva contact to mucous membranes, saliva contact to fresh, non-scabbed skin wounds, and scratches. In general the risk of rabies is very low following non-bite exposures; however, there are rare reports of rabies transmission by these routes suggesting that they constitute sufficient risk to consider administration of PEP on a case-by-case basis.
Location and severity of the bite
When a bite is to an extremity, there is adequate time and it is safe for the patient to wait for completion of the 10-day observation and confinement period or for rabies test results to determine whether or not PEP is necessary. Bites to the face and head are more urgent, and consultation with MDH on these cases is recommended (Table 2; Figure 1). Regardless of location, the deeper and more serious the bite wound(s), the greater the urgency for PEP. Normal laboratory turn-around time for rabies testing in Minnesota is 1 to 2 business days. In urgent situations, expedited rabies testing can be arranged by calling MDH at 651-201-5414.
Circumstances of the bite incident
Factors surrounding the circumstances of the bite include the species of the animal, whether the bite occurred in an urban area or a rural area, if there was a history of a skunk on the premises within the past few months, and whether the bite was provoked or unprovoked. A dog or cat living in a rural area is more likely to be exposed to a potentially rabid skunk than one living in an urban setting. A bite occurring during the feeding of wild, feral or stray animals is considered a provoked bite.
Vaccination status of the biting animal
In the United States, rabies vaccine is licensed for dogs, cats, ferrets, sheep, cattle and horses. An animal is currently vaccinated and can be considered immunized if the primary vaccination was given at least 28 days before the biting incident, or if the animal has received a primary vaccine and a booster vaccination within the timeframe recommended by the manufacturer.
Even though rabies occurrence among currently vaccinated animals is rare, out of an abundance of caution, dogs, cats and ferrets are confined and observed for 10 days or euthanized and tested for rabies following a bite to a human. This is the law in Minnesota and is required regardless of the animal’s vaccination status.
Species of the animal and requirements of the confinement and observation period
Dogs, cats and ferrets are the only species that may be confined and observed for 10 days following a bite to rule out rabies risk. Livestock such as horses, cattle, goats and sheep may be confined and observed for 14 days following a bite. There is no such option for wild animals that bite humans; these bites are handled on a case-by-case basis following consultation with MDH (Table 2; Figure 1).
Rationale for confinement and observation period
Animals cannot transmit the rabies virus to humans until the virus is present in the animal’s salivary glands and saliva. Once the disease has progressed to this stage in domestic animals, they will begin to show obvious clinical signs of rabies. The time period between the onset of viral shedding and onset of clinical signs of rabies is known to be at maximum 3 to 4 days in dogs, cats and ferrets. Thus, if a dog, cat or ferret had rabies virus in its saliva at the time of a bite (and could have transmitted the disease to the victim), it will be sick or dead within 3 to 4 days. The 10-day confinement period includes a large safety factor.
In Minnesota, dogs, cats and ferrets are usually confined and observed at home. However, in some Minnesota communities, unless the animal is currently vaccinated for rabies, it must be confined at an approved quarantine facility at the owner’s expense. Any illness in the animal must be reported to MDH, and if the animal dies for any reason during the 10-day confinement and observation period it must be tested for rabies.