In 2021, the US Centers for Disease Control and Prevention (CDC) reported a total of five human rabies cases/deaths, including three cases from September to November linked to bat bites/exposure.
In today’s Morbidity and Mortality Weekly Report (MMWR), health officials discuss the three latter cases.
During September 28–November 10, 2021, CDC confirmed three human rabies deaths in the United States, all in persons who did not seek postexposure prophylaxis (PEP) after bat exposures that occurred during August 2021.
The deaths were associated with three bat species: Lasionycteris noctivagans (silver-haired bat), Tadarida brasiliensis (Mexican free-tailed bat), and Eptesicus fuscus (big brown bat). All three species are common in the United States and have been implicated in previous rabies cases.
One patient submitted the bat responsible for exposure for testing but refused PEP, despite the bat testing positive for rabies virus, due to a long-standing fear of vaccines. The other two patients did not realize the risk for rabies from their exposures, either because they did not notice a bite or scratch or did not recognize bats as a potential source of rabies.
Two of the bat-associated cases were considered avoidable exposures: one was attributed to a bat roost in the patient’s home, the other to the patient picking up the bat with bare hands. Two patients released the bat, rather than capturing it for testing.
“We have come a long way in the United States towards reducing the number of people who become infected each year with rabies, but this recent spate of cases is a sobering reminder that contact with bats poses a real health risk,” said Ryan Wallace, DVM, MPH, a veterinarian and rabies expert in CDC’s Division of High-Consequence Pathogens and Pathology.
Exposure to rabid bats is the leading cause of rabies in humans in the U.S., accounting for 70% of people who become infected. The number of rabid bats reported to the National Rabies Surveillance System has been stable since 2007, which suggests that this uptick in cases of rabies in people may be due to a lack of awareness about of the risks of rabies – and that getting PEP is a life-or-death matter.
The two other deaths occurred earlier in 2021. One was a Minnesota man bitten by a bat. He got the shots, but an undiagnosed immune system problem hampered their effectiveness, CDC officials said. The other victim was bitten by a rabid dog while traveling in the Philippines and died in New York after returning to the U.S.
There were no human rabies cases in 2019 and 2020. The last case in the US was a 55 year old Utah man who contracted who also contracted the virus from a bat and died in November 2018.
Cases of human rabies cases in the United States are rare, with only 1 to 3 cases reported annually.
Preventing transmission of rabies from bats to humans can be accomplished by 1) avoiding contact with bats, 2) safely capturing and testing bats implicated in human exposures, and 3) seeking rapid evaluation for PEP when direct bat contact occurs and rabies cannot be ruled out.
If potentially exposed to a rabid animal, receiving PEP soon after exposure and before symptoms begin is critical. While rabies deaths in people in the United States are not common, CDC estimates that approximately 60,000 people receive PEP each year to prevent becoming ill with rabies. PEP is nearly 100% effective at preventing rabies if received before symptoms start.
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