A single bat scratch can start an illness that is almost always fatal

A California woman picked up what looked like a dead bat with her bare hands at her worksite in October 2024. She felt it move, and possibly bite her, but saw no wound. She never called a doctor or public health officials, and the bat was never tested. About a month later she developed muscle spasms and seizures, and four days after being hospitalized she died of rabies.

Her case, along with a second fatal rabies death in Minnesota the same year, was documented by the Centers for Disease Control and Prevention in a report whose corresponding author is CDC epidemiologist Rebecca Earnest. Both patients recognized they had encountered a bat. Neither realized what that contact could mean, and neither sought the treatment that, administered in time, is nearly 100% effective at stopping the disease before it starts.

Bats cause most of the rabies deaths the U.S. still sees

Contact with infected bats is the leading cause of human rabies deaths in the United States, responsible for at least 7 out of 10 of the people who die from the disease each year, according to the CDC’s overview of rabies. That pattern holds over the long run: among the 42 rabies cases acquired inside the U.S. between 2000 and 2024, bat contact caused 35 of them, or 83%, the CDC’s Morbidity and Mortality Weekly Report on the 2024 deaths found. That is a striking share given that bats make up only about a third of the roughly 5,000 rabid animals confirmed in the U.S. each year, with raccoons, skunks and foxes accounting for most of the rest.

Rabies itself is rare in this country, with fewer than 10 human deaths reported annually, the CDC notes, because more than 90 million cats and dogs are vaccinated against it each year and wildlife agencies distribute over 5 million oral vaccine baits to control the virus at its source. But the disease has not gone away in wildlife: it is found in every state except Hawaii, and the CDC estimates that nearly three out of four Americans live in a community where animals carry it.

The bites that kill are often too small to notice

Both 2024 deaths shared the same failure point: the victims knew a bat had touched them and still did not seek care. The MMWR report attributes that gap to how physically slight a bat encounter can be. North American bat species are small, and their teeth can leave puncture wounds too faint to see or feel, a phenomenon the report’s authors call a “trivialized or inapparent” exposure. The Minnesota patient, who was reported to have killed a bat in her sink with a hammer, wore a hearing aid, used a machine to treat sleep apnea, and routinely drank alcohol, all factors the CDC says can reduce a person’s ability to notice or recall direct contact with an animal while it happens.

Because of that gap, the CDC’s Advisory Committee on Immunization Practices recommends that anyone who wakes up in a room with a bat present, even without a bite mark, undergo a rabies risk assessment, and the agency separately advises against ever handling a bat with bare hands, since sick bats can appear dead. Investigators who traced the two 2024 deaths, detailed in a Minnesota Department of Health press release on its case, interviewed 384 people who had contact with either patient during their infectious period and recommended that 45 of them, about 12%, receive preventive treatment as a precaution.

Once symptoms appear, the disease is almost never survivable

Rabies has an incubation period that can run from several weeks to several months, during which the virus travels from the site of exposure toward the brain without producing symptoms. The California patient’s first symptoms did not appear until roughly a month after her bat encounter. Once clinical signs of rabies do appear, “the disease is nearly always fatal,” the CDC states on its rabies overview page. Early symptoms mimic the flu, with fever, weakness and tingling or itching at the exposure site, before progressing within about two weeks to the classic signs of advanced rabies: anxiety, confusion, hallucinations, heavy salivation, aggressive behavior and a paradoxical panic at the sight of water despite intense thirst.

Post-exposure prophylaxis, the treatment that must begin before those symptoms start, combines immediate wound washing with human rabies immune globulin and a four- or five-dose vaccine series. Roughly 100,000 Americans receive this treatment each year after a possible exposure, and the CDC says it is nearly 100% effective when given in time. That effectiveness is what makes the two 2024 deaths, and cases like them, avoidable rather than inevitable: both patients had a window during which treatment would almost certainly have saved them, and both let that window close by not reporting the encounter.

Global travel carries its own version of the same risk

The domestic bat problem is a narrower version of a much larger global one. Since 1990, more than 80 people in the United States have died after being infected with rabies while traveling abroad, according to the CDC, mostly in parts of Africa, Asia, and Central and South America where dog rabies remains common and post-exposure treatment can be difficult to access quickly. Worldwide, domestic dogs cause more than 95% of an estimated 70,000 human rabies deaths every year, a toll the CDC and its International Rabies Taskforce partners have worked to reduce through large-scale dog vaccination campaigns, though funding gaps still leave many at-risk regions short of coverage.

The throughline from a California worksite to a village in a country with endemic dog rabies is the same: rabies gives almost no second chances once symptoms begin, and the only real defense is treating a bite, scratch, or even an unclear brush with an animal as reason enough to call a doctor. The CDC’s own framing of the 2024 deaths makes that point directly, describing increased public awareness of bat risk, even after contact that leaves no visible mark, as the single change most likely to prevent the next one.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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