Rabies is rare in humans in the United States, but potential exposures are common. Because rabies is nearly always fatal once symptoms develop, appropriate exposure assessment and timely post-exposure prophylaxis (PEP) are critical.

Not every animal bite or encounter requires rabies PEP. The species involved, type of contact, circumstances of the exposure, geographic location and whether the animal is available for observation or testing all affect risk.

For animal bites or possible rabies exposures in Douglas County, health care providers should contact Douglas County Environmental Health first at 541-440-3574. Environmental Health can assist with exposure assessment, animal follow-up and determining whether additional rabies evaluation is needed.

What Is Considered a Rabies Exposure?

Rabies virus is primarily transmitted when saliva or nervous system tissue from an infected mammal comes into contact with broken skin or a mucous membrane. Potential exposures include:

• A bite that penetrates the skin
• A scratch potentially contaminated with saliva
• Saliva contacting an open wound or broken skin
• Saliva contacting the eyes, nose or mouth
• Direct physical contact with a bat when a bite or scratch cannot be ruled out

Simply being near an animal is not considered an exposure. Petting an animal, saliva contacting intact skin or contact with blood, urine or feces generally does not constitute a rabies exposure.

Bats are the primary reservoir for rabies in Oregon. Other mammals, including cats, dogs, foxes, raccoons, skunks and livestock, can become infected through contact with a rabid bat.

Animal species is therefore an important part of the exposure assessment. Small rodents such as mice, rats and squirrels are considered very low risk in most circumstances. Domestic dog, cat and ferret exposures can often be managed through observation when the animal is healthy and available, while bat exposures require particular attention.

Travel history also matters. Rabies epidemiology differs significantly outside Oregon and outside the United States. In many countries, dogs remain an important source of human rabies.

Pay Special Attention to Bat Encounters

Bat bites can be small and may not leave an obvious wound. A patient does not necessarily need to remember being bitten for an encounter to warrant further assessment.

PEP may need to be considered when there was direct contact with a bat and a bite or scratch cannot be ruled out. Certain situations may also require additional assessment when the person may not be able to reliably determine whether contact occurred.

If a bat may have exposed a person, advise the patient not to release the bat. When it can be done safely, the bat should be contained so testing can be considered. Contact Douglas County Environmental Health at 541-440-3574 for guidance before releasing or disposing of the animal.

When evaluating a possible rabies exposure, obtain as much information as possible about:

• Animal species
• Date and location of the exposure
• Type and location of contact or injury
• Whether the skin was broken
• Whether saliva contacted the eyes, mouth or an existing wound
• Whether the encounter was provoked or unprovoked
• Animal ownership and vaccination status, if known
• Whether the animal is currently healthy
• Whether the animal is available for observation or rabies testing
• Any recent travel or possibility that the animal originated outside Oregon

Immediately wash bites and other wounds thoroughly with soap and water. Evaluate wounds for other appropriate care, including bacterial infection risk and tetanus vaccination.

Then contact Douglas County Environmental Health at 541-440-3574. Environmental Health should be the first point of contact for animal bites and potential rabies exposures in Douglas County and can help coordinate the next steps based on the animal and exposure circumstances.

Dogs, Cats and Ferrets

A healthy dog, cat or ferret that bites a person can often be confined and observed for 10 days rather than immediately initiating PEP. If the animal remains healthy throughout the observation period, it was not infectious with rabies at the time of the bite.

If the animal becomes ill or dies during the observation period, Douglas County Environmental Health should be contacted immediately so the need for rabies testing and human PEP can be reassessed.

Whether observation is appropriate depends on the individual circumstances. Providers should contact Environmental Health rather than independently determining that an animal can be released from observation or that PEP is unnecessary.

When PEP Is Recommended

Rabies PEP is highly effective when administered appropriately before symptoms develop.

For a patient who has not previously received rabies vaccination, PEP consists of:

• Thorough wound cleansing
• Human rabies immune globulin (HRIG) once at the beginning of treatment
• Rabies vaccine on days 0, 3, 7 and 14

Patients with immune disorders should receive an additional vaccine dose on day 28.

For patients who have previously completed an appropriate rabies vaccination series, PEP consists of vaccine on days 0 and 3. HRIG should not be administered to previously vaccinated patients.

Administration errors can reduce the effectiveness of rabies prophylaxis.

For previously unvaccinated patients, the recommended HRIG dose is 20 IU/kg. As much of the dose as anatomically feasible should be infiltrated into and around the wound or wounds. Any remaining volume should be administered intramuscularly at a site distant from the vaccine.

HRIG and the first dose of rabies vaccine should not be administered in the same syringe or at the same anatomical site.

Rabies vaccine should be administered intramuscularly in the deltoid for adults. The anterolateral thigh is acceptable for young children. Rabies vaccine should not be administered in the gluteal area.

If HRIG was inadvertently omitted when PEP was started, it can generally still be administered through day 7 of the vaccine series.

Do Not Wait for Symptoms

PEP is intended to prevent rabies before disease develops. Once clinical rabies develops, the disease is nearly always fatal.

Patients presenting days or even weeks after a potential exposure should still be evaluated. A delay between exposure and presentation does not automatically mean it is too late to provide PEP as long as the patient has not developed signs of rabies.

Rabies risk assessments can be nuanced. Unnecessary PEP can be costly and burdensome, while missing a meaningful exposure can have devastating consequences.

For animal bites, bat encounters or other possible rabies exposures in Douglas County, contact Douglas County Environmental Health first at 541-440-3574.

Environmental Health can assist with animal-related risk assessment, observation and testing and coordinate with other public health partners when additional evaluation is needed. A careful exposure history and early consultation can often prevent unnecessary treatment while ensuring people with meaningful exposures receive appropriate care.