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.

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.” 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.

All three patients died between two and three weeks after their symptoms began.

In its report, the CDC suggested that the uptick in rabies deaths is because people may not be aware of the risks of the disease.

The CDC also warned people to never touch or handle bats, which are the leading cause of rabies in people — accounting for 70% of infections in the U.S. Raccoons, skunks, and foxes are other common causes in the U.S.

Infected bats spread the virus through their saliva, typically from a bite. However, the saliva can also enter the body through a cut or break in the skin.

If a person has come into contact with a bat, the CDC recommends calling the state or local health department so the animal can be trapped for testing. They should also immediately wash wounds with soap and water

The person should also not delay speaking to a health care professional or seeking urgent medical to determine whether or not they need post-exposure shots. Post exposure shots are highly effective in preventing death if given soon after expusure.