Rabies Risk Assessment: Test Your Knowledge

Erin R. Whitehouse, PhD, MPH, RN


August 08, 2019

Editorial Collaboration

Medscape &

Completion of Risk Assessment

First, conduct a risk assessment. The local health department can serve as a resource. Assess all of the following in order to evaluate rabies exposure risk:

  • The type of animal involved;

  • Epidemiology of rabies in the local jurisdiction, because the primary animal reservoirs for rabies vary by geography;

  • Health status of the animal;

  • Type and anatomical location of exposure; and

  • The availability of the animal for rabies testing or observation for symptoms of rabies.

Bat rabies is endemic in every US state except Hawaii. Although the risk of an individual bat having rabies is less than 1 in 100, those that come near humans are more likely to be infected.[4,5] Abnormal behavior, especially around humans, can be a sign that an animal has rabies. Because the bat in this case was not available for testing, the clinician should assume the worst—that the bat could have been infected with rabies.

Next, determine whether the child actually had contact with the bat. According to ACIP guidelines, if a bat is found in the same room as a person who might be unaware that direct contact has occurred (eg, bite, scratch, saliva exposure) or is unable to communicate contact to an adult, such as a child, that person should be considered exposed and treated.[1,2] In this case, a 3-year-old is not a reliable source. In addition, the bat was found in the bedroom, so it must be assumed that it had access to the sleeping, unattended child.

Given that the bat is unavailable for testing, it was found in the child's bedroom, and the child is unable to provide a reliable history, PEP would be recommended.

After completing the risk assessment, the child should be given one dose of rabies immunoglobulin (20 IU/kg) and four doses of rabies vaccine over the next 2 weeks, according to current ACIP guidelines.[1,2]

Case 2: Suspected Human Rabies

A 47-year-old woman arrived in the emergency department with shortness of breath, anxiety, and difficulty swallowing water. Results of initial diagnostic testing, including a complete blood count and electrocardiogram, were unremarkable, and she was discharged home. The next day, she returned with shortness of breath and progressive paresthesia in her left arm. She was agitated and had difficulty answering questions. New mosquito bites were found on her legs, and she reported hiking in the northeastern United States about 2 weeks before illness onset. Numerous tests, including blood and cerebrospinal fluid (CSF) cultures, did not reveal a specific cause. Within 3 days, her clinical condition deteriorated. She was diagnosed with encephalitis and required intubation for airway protection. Family members reported that she had told them about bats in her attic about 6 months ago, but did not say that she had had direct contact with them.

Given symptoms of progressive encephalitis and potential contact with bats, the case was determined to be a suspect human rabies case.