The Centers for Disease Control and Prevention issued a warning Thursday about the risk of rabies after three Americans — including a child — died from the disease over a six-week period last year.

ABC News reported that all three patients contracted rabies after being exposed to bats. This brings the total number of rabies cases in 2021 to five, which officials say is concerning considering there were no cases reported in the U.S. in 2019 and 2020.

“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,” Dr. Ryan Wallace, a veterinarian and rabies expert in the CDC’s Division of High-Consequence Pathogens and Pathology, said in a press release.

The deaths occurred between Sept. 28, 2021, and Nov. 10, 2021, with one case each in Idaho, Illinois, and Texas, according to a report published by the CDC. Two of the deaths were described as “avoidable exposures.”

WTRF detailed that one involved a bat roost in a person’s home and the other involved a patient picking up the bat with bare hands. None of the three patients, all-male, received post-exposure shots that can prevent the rabies virus from infecting a person and causing symptoms to develop.

According to the CDC, one patient refused the shots due to a “long-standing fear of vaccines” and the other two did not realize they were at risk for rabies due to their exposures. Once a person starts to develop rabies symptoms, which include fever, vomiting, difficulty swallowing, confusion, and hallucination, it means the disease has progressed to the point where it is almost 100% fatal.