Rabies-Positive Raccoons Found in California Raise Concerns

This month, a couple of raccoons in Westlake Village, a suburb of Los Angeles, have set off alarm bells, not just locally, but even reaching as far as Georgia. These raccoons, discovered three weeks apart, represent the first confirmed cases of rabies in the county since 1973.

Rabies is a serious virus that attacks the nervous system, typically spread through the saliva of infected animals, mainly via bites. In various regions across the U.S., the prevalent rabies variants are determined by the animals most likely to transmit the virus. For California, bats and skunks are the primary carriers, making their variants the most common. Other species, such as dogs, cats, or coyotes, can still contract rabies through other animal transmission. Perhaps what worries experts the most is the potential for a new rabies variant to emerge that could take hold in yet another animal group.

Dr. Ryan Wallace, a veterinary epidemiologist at the CDC, expressed concern that if the sick raccoons test positive for a rabies variant typically found in raccoons, it might prompt a substantial federal and state response to control this new strain and reduce human risk.

“Raccoons tend to be quite unafraid of humans, or at least they adapt well to human environments,” Wallace said. “So if a rabies virus shifts to a species with such a close ecological relationship to humans, that could lead to a spike in human exposures.”

The presence of these ill raccoons is a troubling sign that rabies might be on the upswing, not just in California but across the United States. In September, the CDC reported a staggering 76% increase in individuals receiving rabies post-exposure treatment. Additionally, California’s count of rabid animals this year has hit a 28-year high.

Still, it’s worth noting that challenges in national data analysis leave both state and federal experts uncertain about whether rabies cases are genuinely rising or merely fluctuating in certain areas.

‘Very Scary’

Rabies is strikingly different in its ability to infect and inevitably cause death in any mammal. Dr. Monica Gandhi, an infectious disease expert with UC San Francisco, called the virus, which targets the nervous system, “very, very scary.”

The virus essentially goes straight into the brain, causing initial headaches that lead to severe symptoms such as seizures, paralysis, and rapid neurological changes including behavioral shifts, hallucinations, and delirium, she explained.

The reality is that rabies is nearly always fatal for both humans and animals once symptoms appear. Thankfully, anyone exposed can be given vaccines or immunoglobulin shots post-exposure to halt the virus from multiplying, ultimately saving lives.

In the U.S., public health labs test approximately 100,000 animals yearly, with around 4,000 turning out to be rabid. On average, fewer than ten people die from the disease annually. The last fatality reported in California happened in 2024 when an art teacher in Merced County contracted the virus after interacting with a bat in her classroom.

California Breaks a Record

You might find it interesting to know that while there haven’t been confirmed human cases of rabies in California for several years, the state’s wildlife has seen a different story. So far this year, at least 368 rabid animals have been identified, which marks the highest number since 1998. Most of these cases were in Southern California, primarily involving bats and skunks.

Despite this uptick in wildlife rabies, as Beth Deines from the California Department of Public Health mentioned, the risk to the general public remains low. “We don’t exactly know why we’re seeing more cases, but it can vary significantly from year to year and by season,” she noted in an email. “Currently, there’s no indication that rabies has spread beyond bats and skunks in California.”

Shannon Bennett, chief science officer at the California Academy of Sciences, pointed out that it remains unclear if we’re seeing more rabid animals or simply more people bringing sick wildlife in for testing. “It’s mostly passive reporting by the public,” he remarked, suggesting that a proactive sampling of wild populations would better reveal the true prevalence of rabies among bats.

Factors contributing to this increase could include urban encroachment into wildlife habitats, or even climate change, as warmer temperatures might help the virus reproduce more quickly.

“It’s obvious that warmer climates create more favorable conditions for viruses and microbes,” Bennett suggested.

Wallace confirmed that the two raccoons found in Southern California tested positive for the bat strain of rabies, which, while a relief, doesn’t entirely ease concerns. He emphasized that continued vigilance is necessary since “repeated introductions raise the likelihood that raccoons could evolve into a new reservoir for the virus in the LA area.”

A National Mystery

The increasing number of detections in California comes at a time when the CDC is noting a possible rise of rabies in other regions as well. In September, CDC reported a significant spike in individuals receiving rabies immunoglobulin shots, indicating exposure, with a notable 76% rise during the same period. A 33% uptick in rabies vaccine administration was also recorded compared to the previous year.

Wallace mentioned that the numbers have shot up during May and June, and vaccine sales have remained heightened through early October. However, they can’t definitively determine if this trend is widespread across the nation or localized and what animal species might be responsible.

Interestingly, CDC researchers utilized a language AI model to analyze media reports about rabid animals across the U.S., which revealed a “generalized increase” in exposures in states such as California, Indiana, Ohio, and Maine. “So far, the only slight indication we’re seeing points to an increase in rabies among bats,” Wallace noted.

For individuals worried about potential rabies exposure, Wallace advised against handling dead wildlife and emphasized the importance of keeping pets vaccinated. He also recommended that anyone who has contact with bats consult a doctor, as bat bites can often go unnoticed due to their tiny teeth.

Flying Blind

The CDC has developed advanced models to sift through county and state public health reports to identify unusual patterns, and these models had previously uncovered a rabies outbreak in Texas earlier this year.

However, budget cuts since the Trump administration have hindered the CDC, causing them to lose about 30% of their staff. While Wallace didn’t delve deeply into funding specifics, he pointed out that maintaining the 130 labs that test 100,000 animals requires consistent efforts and resources.

“When everything is functioning well, our tools can be very innovative,” he said, acknowledging that at this moment, they’re not quite up to date. The last rabies surveillance report was from 2024, and there’s no clear timeline for the next one.

He added, “We’re over a year behind in data flow, which complicates our ability to confidently answer questions about national rabies trends.”

While this doesn’t mean that the U.S. is blind to rabies trends altogether, as local health departments are proficient in surveillance within their areas, Wallace admitted that aggregating broader national trends is much tougher to identify quickly.

Dr. Matt Willis, an infectious disease expert and a former public health officer for Marin County, pointed out that California’s strong health system should help in catching local rabies trends, but the CDC’s limitations could lead to missing wider viral patterns being observed.

Willis urged caution, noting the difficulty in drawing accurate comparisons as states often use different methods for tracking rabies occurrences. And with that point, if the CDC ever does catch up on analyzing the backlog of data, there’s a lingering concern that a more significant issue may be lurking in the shadows, unnoticed.