LA hit a record high for typhus cases last year. Why is the flea-borne disease so hard to eradicate?

L.A. County had its worst year on record for flea-borne typhus cases, reporting 220 cases in 2025. Experts say the disease is difficult to eradicate because humans, animals and vectors all play a part in transmission.

The department investigated outbreaks in central L.A., Santa Monica and Willowbrook. This year, there are 17 reported cases of typhus.

Typhus is a bacterial disease spread by infected fleas, which are most commonly found on rats, free-roaming cats and opossums.

How did we get here? 

L.A. County has seen an increase in flea-borne typhus cases year-over-year, Aiman Halai, medical epidemiologist at the L.A. County Department of Public Health, told LAist.

“These fleas live on reservoir animals, which in L.A. County are primarily rats, free-roaming cats and opossums,” Halai said. “Any factor that increases the interaction between these animals and humans will increase the risk of flea-borne typhus.”

There is an indirect link between weather and typhus, Halai said, because weather affects animal movement and human behavior, like how much time people spend outside.

Halai said diseases like typhus are difficult to eradicate.

“It's hard to control diseases that involve humans, animals and vectors, because there are so many different factors that play a part in transmission,” Halai added.

As for hospitalizations associated with typhus, Halai said the disease is relatively mild but can progress to serious illness.

“What we're finding is that nine out of 10 cases that we have identified have been hospitalized, and there may be many more cases that are undiagnosed and have not resulted in severe disease,” Halai added.

Is this happening anywhere else? 

Other parts of the U.S. are seeing increases in typhus cases, including Texas, Halai said.

Closer to home, the city of Long Beach issued a health alert warning residents about an uptick in typhus cases last year. The city, which has its own health department, reported 39 cases of typhus in 2025, of which 72% were hospitalized.

Jennifer Ann Gonzalez, public affairs officer for the Long Beach Health Department, said following last year’s increase, the department upped its mitigation efforts, including public education and vector control.

“The localized typhus outbreak reported in summer 2025 was controlled, and no additional cases associated with the outbreak have been reported,” Gonzalez said in an email. “To date, no outbreaks have been identified in 2026.”

How to protect yourself and your neighbors

The disease is not spread from person to person and is treatable with antibiotics. Symptoms can include high fever, nausea, muscle aches, rash and cough. People who think they have it should talk to their healthcare provider.

Infection occurs when feces from infected fleas are rubbed into cuts or scrapes, including flea bites, or rubbed into the eyes.

“Our cases have been as young as one year of age or to over 80 years of age. It's really a disease that can affect anyone at any time in L.A. County,” Halai said.

Pets don’t show symptoms, Halai added, but they act as a vehicle to carry infected fleas from reservoir animals to humans.

To protect yourself and your pets:

• Use flea control products for pets.
• Store trash and other food in secure bins to avoid attracting animals.
• Close crawl spaces and attics to discourage animals from nesting around your home.
• Avoid petting or feeding free-roaming animals, including cat colonies.
• When outside, use a bug repellent that protects from fleas. 

What to look out for

Typhus symptoms can start within two weeks after contact with an infected flea and can include fever, headache, muscle pain, nausea and rash.

L.A. County residents can find more information here.