Outbreaks, Alerts and Hot Topics

Rabies Prevention and Reminders for Patient Families

Column Editor: Angela Myers, MD, MPH | Director, Division of Infectious Diseases | Professor of Pediatrics, UMKC School of Medicine | Medical Editor, The Link Newsletter

In the last week of September, a man in Illinois died of rabies.¹ How is this possible given widely available post-exposure prophylaxis (PEP) in the U.S.? It’s simple. He refused PEP after waking to find a bat on his neck approximately six weeks prior. Two weeks prior to his death, he developed classic symptoms of rabies characterized by neck pain, headache, difficulty speaking, loss of control of his arms and numbness in his fingers. The incubation period of rabies ranges from weeks to months and may be on the shorter side the closer the bite is to the brain.² This is because the virus has a shorter distance to travel to get to the brain. Once symptoms develop, progression of the disease is generally quick, ending in 10 days or so.

In 2018, there were nearly 4,600 reported rabid animals, nearly all of which (93%) were wild animals.³ (Figure 1) While bats have not always been the most infected animal, they are the main cause of rabies death in humans owing to more frequent interactions. (Internationally, the main cause of animal rabies, and subsequent human rabies, continues to be domestic dogs). Raccoons, skunks and foxes are the next most common animals infected in the U.S.³ (Figure 2) Cats and dogs are the most common domestic animals infected with rabies, accounting for 4.9% and 1.3% respectively in this surveillance study.³ Nearly all domestic animals that acquire rabies are unvaccinated.

Post-exposure prophylaxis is 100% effective in preventing rabies and includes rabies immune globulin (RIG) 20 IU/kg injected into the bite wound (if one is known) with any remainder of the dose being injected into the deltoid muscle of the arm contralateral to the rabies vaccine. The vaccine is a 1mL IM infection given on days 0, 3, 7 and 14. People who are immunocompromised should receive an additional dose of vaccine on day 28. Due to availability and effectiveness of the PEP regimen, there are very few human cases of rabies in the U.S. In 2018, there were three deaths from rabies and none in 2019.

There is so much to go over with patients and families during well-child visits, and rabies prevention seems like yet another topic to add to the list. It is important to talk with families about what to do if they have a bat in the home or are bitten by a wild animal, cat or dog and they are unsure of vaccination status. (Table) In some instances, PEP can be avoided if the wild animal is safely caught, euthanized, and tested, or can be observed for 10 days, in the case of a cat or dog. Recently, a community pediatrician contacted me with this very scenario. While at college, her daughter discovered a bat flying in her living room in the middle of the night. The bat had not been in the bedrooms where people were sleeping, and the bat was caught and tested negative. (See photo of the bat stuck to a fly trap on the living room window). This is the best-case scenario—you know where the bat has been, and it is captured and tested. However, if a bat is found in the bedroom of someone sleeping or is unable to be captured, PEP should be given as soon as possible within 24 hours.

Additionally, inspection of the home to determine where the bat gained access is critical to prevent future intrusions. In older homes, several entry points may be found and require repair. In the instance above, the landlord made sure that much-needed bat proofing occurred.

Bat stuck to a fly trap on the living room window of a college home (above).

Figure 1. Geographic regions of wild animal rabies in the U.S. and Puerto Rico (CDC)

Figure 2. Cases of wild animal rabies in the U.S. from 1967-2018 (CDC)

Table. Animal Exposure Anticipatory Guidance for Patients and Families Domestically and Internationally

References:

1. https://www.npr.org/2021/09/29/1041457232/rabies-illinois-man-death-rare-public-health.
2. https://www.cdc.gov/rabies/symptoms/index.html.
3. Ma X, Monroe BP, Cleaton JM, et al. Rabies surveillance in the United States during 2018. J Am Vet Med Assoc. 2020;256:195-208.