The County of Los Angeles Public Health has warned the public of the detection of flea-borne typhus. Though not spread from human to human, flea-borne typhus (sometimes called murine typhus) can spread to humans from bacteria found in infected fleas. Infection occurs when feces from infected fleas are rubbed into cuts or scrapes on the skin or rubbed into the eyes.

According to the public health website, flea-borne typhus is an acute febrile illness and is caused by the Rickettsia (R.) typhi bacteria.

Flea-borne typhus, which occurs year-round but tends to peak during the late summer and fall, saw a record high of 187 cases in 2024 (excluding Long Beach and Pasadena, which have their own agencies); however, localized clusters and outbreaks have been identified primarily in Central Los Angeles and South Los Angeles areas. Currently, 106 cases have been reported.

In LA County, according to the LA Public Health agency, the primary animals known to carry infected fleas include rats, free-roaming cats and opossums. People with exposure to these animals are at risk of acquiring flea-borne typhus. Pets, such as dogs and cats, that are allowed outside may also come into contact with infected fleas and could carry them to humans. Infected animals are not known to get sick from flea-borne typhus.

Typhus can be a mild, self-limited illness or it can present as a severe disease requiring hospitalization. Symptoms start within two weeks after contact with an infected flea and may include: Fever, Headache, Muscle pain/myalgia, Nausea/vomiting, Rash sparing the palms and soles

Rarely swelling may occur at the lining of the brain (meningitis) or in the heart valves (endocarditis). Fatalities are uncommon, but have been observed. The first flea-borne typhus deaths since 1993 in LA County were reported in 2022 (see MMWR report).

There are no vaccines to prevent flea-borne typhus. It can be treated with antibiotics. Doxycycline is the treatment of choice.