A Northern Californian has been confirmed as the fourth-ever person diagnosed with a newly recognized and rare tick-borne disease that causes symptoms similar to Rocky Mountain spotted fever.

The California Department of Public Health confirmed the latest case of Rickettsia lanei bacteria in a patient who was diagnosed in April of this year. Two other California cases were reported in 2004 and 2023.

Public health officials told The Times that the infected person “was seriously ill, hospitalized and has since been discharged and is recovering.”

It is unclear how long the person was in the hospital or what their symptoms were. The state agency said it could not disclose the home county of the person but confirmed the infected person lived and worked in Northern California.

Rickettsia lanei comes from the spotted fever group Rickettsia, bacteria transmitted to humans from the bite of an infected tick.

In California three types of ticks — the American dog tick (Dermacentor similis), the Pacific Coast tick (Dermacentor occidentalis) and the brown dog tick (Rhipicephalus sanguineus) — can transmit the bacteria that cause Rocky Mountain spotted fever in humans and dogs, according to the California Department of Public Health.

Symptoms of Rocky Mountain spotted fever can range from fever and a rash to long-term effects that include damage to internal organs or neurological disorders.

The tick-borne disease has been spreading globally since the early 2000s, most notably in Mexico and Brazil, with reported fatality rates that can exceed 50%, according to a study published by UC Davis.

What is Rickettsia lanei?

Rickettsia lanei bacteria were identified this year in a few Pacific Coast ticks, including a tick in Contra Costa County, according to SFGate, where the latest case was first reported in April.

The new bacterium was added to the list of potentially transmittable pathogens in 2024 by the state public health department after its severe symptoms were studied in two cases of infected men nearly 20 years apart, according to a report published in the Centers for Disease Control and Prevention Emerging and Infectious Diseases journal.

“Sustained investment in public health has enabled development of the advanced molecular tools that detected these infections,” the California Department of Public Health said in a statement to The Times.

According to the report, both men fell ill after spending time outdoors, one playing golf at five courses in Alameda and Contra Costa counties within 14 days of the onset of his symptoms. This first patient had fever, headaches, muscle pain, malaise, loss of appetite, diarrhea and abdominal pain, among other symptoms. His condition worsened on his third day in the hospital, according to the report. The man was ultimately in the hospital for 22 days, including 11 in the intensive care unit with a primary diagnosis of rocky mountain spotted fever and a secondary diagnosis of acute kidney injury.

The other infected person had visited and camped at a county park and state beach in San Mateo and Marin counties. The second man reported a five-day history of headaches, vomiting, light sensitivity, neck pain and confusion, according to the report. On the third day of hospitalization, the man became comatose and was intubated, the report stated. After 13 days, he was discharged with a primary diagnosis of severe Rickettsia.

Researchers have known about Rickettsia lanei since 2018 when it was detected in rabbit ticks in Sonoma County, but they didn’t know its potential harm to humans because the rabbit tick rarely bites people.

“The Pacific Coast tick, which bites humans more frequently, may occasionally acquire the organism from an infected rabbit, which is the most likely route for the rare human infections that have been identified,” the state health agency said.

Should I be worried about contracting Rickettsia lanei?

Human infections are rare but could be underreported because Rickettsia lanei symptoms are very similar to those of rocky mountain spotted fever, said Janet Foley, veterinarian and disease ecologist at UC Davis.

“I think it’s so new that I don’t know if anybody’s really gotten a grant to study it or put it under a microscope,” Foley said.

Rickettsia lanei bacteria cases could also have gone undetected for so long because some cases were not severe, she said.

Foley said Californians should be aware of Rickettsia lanei and take precautions against tick bites.

How to keep disease-carrying ticks at bay

The best way to avoid ticks and tick bites is to be vigilant in your surroundings, Foley said, noting that ticks can transmit other diseases such as Lyme disease.

To keep a disease-carrying tick at bay, Foley recommends:

• Covering up your arms and legs when outdoors by wearing pants and long-sleeved shirts.
• Staying out of the grass where a tick can latch onto your clothing. Instead stay on a cleared path.
• Wearing light-colored clothing so it’s easier to spot a tick if one jumps on you.
• After an outdoor activity, take off your clothes, toss them in the wash and take a shower.
• If your dog goes with you for outdoor activities, give it a bath and then apply tick medication.

Nara Organics recalled its whole milk baby formula after a California child and two others were sickened by potentially fatal infant botulism, federal officials said.

Parents should immediately stop giving the formula to their children, said officials from the U.S. Centers for Disease Control and Prevention. Unopened cans should be returned or thrown away.

All three infants, who ranged in age from 2 to 5 months, were hospitalized and given a drug to treat infant botulism, officials said. No deaths have been reported.

Parents should quickly seek medical care for an infant who has difficulty swallowing, poor feeding, loss of head control or decreased facial expression, the CDC said. Other symptoms include constipation, drooping eyelids, sluggish pupils and a weak cry.

Because symptoms of infant botulism can take several weeks to begin, officials said, parents of children who have consumed the formula should monitor their child for signs for a month after the product was last consumed.

Nara Organics formula is sold online and at Target stores. The two other infants who were hospitalized were from Pennsylvania and Washington.

The New York company said in a statement that so far its product had not tested positive for the bacterium Clostridium botulinum. Nevertheless, the company said, it decided to recall all products currently on the market.

“We sincerely apologize for the concern and distress this announcement causes our customers,” the company said. “We are committed to leading with transparency and accountability throughout this process as we work to identify further information.”

Consumers can find refund information on the company’s website at nara.com.

Infant botulism happens when swallowed spores from the bacterium infect a baby’s large intestine and make a toxin in it. If not treated, the child can experience a progressive paralysis that can lead to breathing difficulties and require weeks of hospitalization.

Last year, another manufacturer recalled its product — ByHeart Whole Nutrition Infant Formula — after an outbreak of infant botulism sickened dozens of babies across the country.

In early 2022, around the time the Omicron variant started driving a new surge in COVID-19 cases, researchers at James DeGregori’s University of Colorado Anschutz lab noticed something unusual: When lab mice with dormant breast cancer cells were infected with either influenza or SARS-CoV-2, the animals were significantly more likely to develop aggressive lung tumors.

What’s true for a mouse isn’t always true for a human. But when the team examined healthcare databases, they were surprised to find that something similar appeared to be going on in the human population.

Analysis of records from the U.K. Biobank showed that cancer survivors who contracted COVID in 2020 — when the virus was new and no vaccine was available — were significantly more likely to die of recurring cancer than patients who didn’t get the virus, particularly within the year after their COVID infection.

Analysis of a separate U.S. breast cancer database found that breast cancer patients in remission who got COVID were significantly more likely to develop metastatic lung tumors than patients who did not contract the virus.

The University of Colorado researchers couldn’t analyze influenza’s effects as thoroughly — most flu infections don’t make it into medical charts, as patients often ride out routine cases at home. They also weren’t able to take into account whether the severity of a patient’s COVID infection influenced the likelihood of a cancer recurrence. But COVID’s novelty gave the team the data it needed to track the effects of viral inflammation on cancer recurrence. Their results were published last year in the journal Nature.

“When [cancer] comes back, it comes back with a fury,” DeGregori said. “We think that these virus infections can be almost like fuel for the fire.”

Unwelcome as COVID’s emergence was, the sheer scale of its spread has vastly deepened science’s understanding of the ways that viruses can continue to affect a human body long after the initial illness has passed.

Scientists need a critical mass of data to be able to identify statistically significant patterns. In the case of a global pandemic “where the whole population gets infected, basically you have a denominator of 7 billion people,” said Dr. Stanley Perlman, a University of Iowa microbiologist who studies coronaviruses.

The rapid increase in patients suffering from long COVID supercharged research on post-viral syndromes — the complex collection of lingering symptoms doctors have long observed in some patients infected with pneumonia, flu or other viruses.

Now, as more years of post-pandemic data have accumulated, scientists are also able to look more closely at the complicated relationship between COVID and cancer, a disease that takes significantly longer to make itself known.

“This is something that merits more attention,” said Dr. Aditya Bardia, director of Translational Research Integration at the UCLA Health Jonsson Comprehensive Cancer Center. Bardia’s lab has also observed associations between COVID infection and breast cancer recurrence; that research has not yet been submitted for peer review.

There isn’t sufficient evidence to indicate that COVID is an oncogenic, or cancer-causing, virus, a half-dozen researchers contacted for this article said. The virus has some significant structural differences from known oncogenic viruses such as human papilloma virus, which is linked to cervical cancer, and hepatitis B and C, which are associated with liver cancer.

But the pandemic has left some evidence that viral infection may play a role in reawakening dormant cancer cells present in a patient’s body before infection.

“COVID and influenza do not cause cancer under themselves, but if you have cancer and you have dormant cancer cells that are normally under control by your immune system, getting a severe case of COVID can help reactivate those existing cancers,” said Dr. Patrick Moore, a virologist and epidemiologist at the University of Pittsburgh.

A sharp increase in metastatic breast cancer cases in the pandemic’s early years was largely attributed to care delayed by pandemic restrictions, rather than a real increase in incidence.

More recent work suggests that “it’s not just the logistics of the pandemic, but it’s really something inherent to infection” behind the association with cancer recurrence, said Melanie Ott, director of the Gladstone Institute of Virology and a professor of medicine at UC San Francisco.

The effect isn’t specific to COVID, as DeGregori’s Nature paper shows, Ott pointed out. One of the body’s natural defense mechanisms against a virus like COVID or influenza is the release of cytokines, proteins that act as chemical messengers helping to coordinate the immune system’s response.

But in some cases of severe infection, the immune system can overcorrect and send out an excess amount of these proteins, a serious and potentially fatal reaction called a cytokine storm.

Research in the early months of the pandemic showed that patients with severe COVID who died or required hospitalization were much more likely to have runaway levels of cytokines, including a particular protein called interleukin-6, or IL-6.

Chronically high IL-6 levels have also been linked to recurrence and metastasis of multiple types of cancer.

DeGregori’s team found that breast cancer cells in mice whose dormant cancers returned after a COVID infection reactivated in response to high levels of IL-6. Their research couldn’t prove that the same biological process happens in humans, DeGregori said. But the fact that a review of real-life patient data showed a high correlation between COVID infection and cancer recurrence makes him think they are on to something.

It’s not a settled question, even among the paper’s authors. Dr. Doug Wallace, director of the Center for Mitochondrial and Epigenomic Medicine at Children’s Hospital of Philadelphia and a co-author on the Nature paper, said he has a “slightly different interpretation” of the data.

IL-6 also inhibits mitochondria, the parts of a cell that generate energy. Wallace thinks that this suppression of the cells’ powerhouses is actually what’s encouraging cancer growth. (Mitochondrial dysfunction is also a prime suspect in the cause of long COVID.)

Other viruses shut down mitochondrial function too, Wallace said. SARS-CoV-2 seems to be particularly good at it, which could be the reason an infection leads to the lingering misery of long COVID in some people or an unexpected recurrence of cancer in others.

Researchers stressed that this area of study is still in its early days, and there is no definitive causal link between COVID infection and cancer recurrence.

“It’s fair to say that [COVID infection] could be added to the long list of theoretical reasons that cancer might be more likely to come back, [but] I’m on the skeptical side of all things. Prove it to me,” said Dr. Eric Winer, director of the Yale Cancer Center. “This is one where I’d say, interesting finding, let’s look more.”

The evidence to date suggests simply that the question is worthy of more study, researchers said. If there is any action people with vulnerable immune systems should take as a result, it’s to continue reasonable precautions against viral infections of all kinds.

“There’s a very, very, very compelling reason for those patients who have chronic diseases to avoid getting a severe case of influenza or COVID or respiratory syncytial [virus] — all of these diseases for which good, safe, effective vaccines exist,” Moore said.