Five people in the United States died from rabies last year, the highest number in a decade, the Centers for Disease Control and Prevention said on Thursday.
Three of those deaths, including that of a 7-year-old child, involved direct contact with bats and occurred over a five-week period starting in late September. The deaths occurred in Idaho, Illinois and Texas, and all three people experienced symptoms three to seven weeks after contact with bats. They died two to three weeks after symptoms began, according to a C.D.C. report.
Rabies is caused by a virus that is usually transmitted through the saliva of an infected animal through a bite. It has one of the highest mortality rates of any disease, but death is preventable: Vaccines taken before symptoms appear are nearly 100 percent effective. Still, rabies causes about 59,000 deaths around the world each year.
Most of the deaths occur in countries where public health resources are inadequate. In the United States, death from rabies is exceedingly rare — in 2019 and 2020, there were no reported cases or deaths. The C.D.C. said the uptick in rabies cases could be because of a lack of awareness about the risks, since the number of rabid bats that have been reported to the National Rabies Surveillance System has been stable since 2007.
Four of the five people who died in late 2021 did not receive the vaccine, according to the C.D.C. Two of the patients did not take vaccines because they did not know about the risk of rabies from their exposures, either because they did not notice a bite or scratch or because they did not recognize the risks of getting rabies from bats, the C.D.C. said.
“The most important thing that we wanted people to take away from this report is that it is a reminder about how dangerous having direct contact with bats can be,” said Amber Kunkel, an epidemic intelligence officer for the C.D.C.
Once the virus reaches the brain, it can cause convulsions, fear of water, excessive salivation and other symptoms. Eventually the infection causes coma and death.
Once symptoms start, rabies is nearly always fatal.
In one case, a man in Illinois who had a bat roost in his home awoke in August to find a bat on his neck, according to a statement from the Illinois Department of Public Health. The bat was captured and tested positive for rabies, but the man declined to take a vaccine because of a longstanding fear of vaccines. About a month after contact with the rabid bat, the man started experiencing neck pain, headaches, difficulty controlling his arms, finger numbness and difficulty speaking, before dying.
In another case, a child in Texas picked up a bat with his bare hands and then released it. A third person died in New York after he was bitten by a dog in the Philippines. He started developing symptoms after he returned to the United States. The C.D.C. said it was not able to determine why the man did not receive a vaccine.
A fourth person from Minnesota who died from rabies last year received the vaccine but his weakened immune system did not respond to it, the C.D.C. said.
In the early 1900s, more than 100 people in the United States died of rabies every year. That number fell to one or two per year since 1960 as pet vaccination, animal control programs and public health surveillance improved, and the rabies vaccine became more available. In 2018, three people died from rabies, the second highest number in the past few years. In 2011, six people died from rabies.
“We have come a long way in the United States toward reducing the number of people who become infected each year with rabies,” Ryan Wallace, a veterinarian and rabies expert at the C.D.C., said in a statement, “but this recent spate of cases is a sobering reminder that contact with bats poses a real health risk.”
In many countries, the greatest risks of rabies are from stray, unvaccinated dogs. In the United States, however, about 70 percent of rabies infections are from exposure to bats. The C.D.C. urges people to avoid contact with bats. If contact occurs, people should talk to their doctors or local public health officials to determine whether rabies vaccines are needed. Bat bites or scratches can be very small and in some cases not visible.
When it is unclear whether there was contact with a bat, such as in cases where bats enter homes while people were sleeping or if children were left unattended, it is essential that people immediately call local health officials for guidance. About 60,000 people receive rabies vaccines each year, according to a C.D.C. estimate.