U.S. health officials are urging people to take precautions and seek treatment when coming in contact with bats after five people died from rabies last year.

Four people died last year after each person came in direct contact with rabid bats, according to a Thursday report from the Centers for Disease Control and Prevention. The fifth patient was bitten by a dog in the Philippines before returning to the U.S.

The report noted that three of those deaths happened in just five weeks at the end of 2021 and that they did not receive life-saving treatment, which includes a rabies vaccine.

Last year saw the most rabies cases in humans in a single year since 2011, CDC rabies experts Amber Kunkel and Ryan Wallace told USA TODAY. No cases in humans were reported in 2019 or 2020.

The uptick in cases may be due to a lack of awareness about the risks of rabies and what to do after potential exposure, the CDC said, because the number of rabid bats reported nationally has remained the same since 2007. The agency recommends contacting a health care professional if a person comes in direct contact with a bat.

“We have come a long way in the United States toward 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,” Wallace, a veterinarian, said in a statement.

The four deaths happened in Idaho, Illinois, Texas and Minnesota. An 80-year-old man refused life-saving rabies shots due to a “long-standing fear of vaccines,” the report said. The two other patients didn’t realize their potential risk for contracting rabies because they didn’t notice a bite or scratch.

One of the individuals had a bat roost in their home while another picked up a bat with their bare hands. 

A bat bit a man while he was sleeping:He died of rabies a month later.

Exposure to rabid bats accounts for 70% of people who are infected with rabies, the CDC said.

After exposure to rabies – a viral disease that infects the central nervous system – the virus must travel to the brain before it causes symptoms, according to the CDC. This process can take weeks to months.

Initial symptoms of the virus may be similar to the flu and can include physical weakness, fever or headache, the CDC said. Infected people may also feel discomfort, prickling or itching in the place they were bitten. Later, symptoms may progress to anxiety, confusion, agitation, delirium, hallucinations and insomnia.

Once symptoms appear, rabies is nearly always fatal, according to the CDC. Fewer than 20 cases have been documented of humans surviving the disease after showing symptoms.

Still, Kunkel and Wallace said in an email to USA TODAY that there’s no need for panic.

“While it is tragic that five people unnecessarily lost their lives to rabies in 2021, they represent only a small fraction of Americans that are exposed to the disease every year,” they said. “This report is a sad and important reminder that direct contact with bats is a leading cause of rabies deaths in the U.S.”

The CDC encourages avoiding direct contact with bats. If you have been in contact with a bat, the CDC says to wash any wounds immediately with soap and water before contacting a health care or public health professional to determine potential risk of rabies.

Bats have small teeth and their bites don’t always leave visible marks, yet rabies can still spread through infected saliva, the CDC warned.

The agency also recommends calling your state or local health department or animal control to help trap the bat to be tested for rabies. Testing a bat can help determine if a treatment known as post-exposure prophylaxis, or PEP, is necessary.

PEP consists of a dose of human rabies immune globulin and rabies vaccine followed by three more doses of the vaccine over the next 14 days, according to the CDC.

PEP, which is used after contact with any rabid animal, is nearly 100% effective in preventing rabies until symptoms develop, according to the CDC.

“Getting PEP is a life-or-death matter,” the agency said.

Rabies deaths in the U.S. are uncommon, but the CDC estimates about 60,000 people receive PEP each year to prevent illness.

“Bats are important species for the environment and eat insects that can carry other diseases,” Kunkel and Wallace said. “The problems come when humans and bats come into contact with one another, which poses risks for both bat and human health.”

Contact News Now Reporter Christine Fernando at cfernando@usatoday.com or follow her on Twitter at @christinetfern.