LOS ANGELES — Los Angeles County health officials are sounding the alarm after reporting a record 220 cases of flea-borne typhus in 2025, the highest number ever documented in the county, with nearly 90% of infected individuals requiring hospitalization.

The Los Angeles County Department of Public Health announced the surge Thursday, highlighting a continued upward trend from 187 cases in 2024 and marking a sharp increase from previous years. The bacterial infection, transmitted primarily through fleas carried by rats, free-roaming cats and opossums, has prompted urgent calls for residents to protect themselves and their pets through simple preventive measures.

Flea-Borne Typhus
Flea-Borne Typhus

"Flea-borne typhus can cause serious illness, but it is preventable with simple steps," Los Angeles County Health Officer Muntu Davis, MD, MPH, said in the statement. "With cases at an all-time high and most requiring hospitalization, it's critical that people take simple steps now, such as routinely using flea control on their pets, avoiding contact with stray animals, and preventing wildlife from living in or around their homes."

Flea-borne typhus, also known as murine typhus, is caused by the bacterium Rickettsia typhi. It is not spread person-to-person but occurs when bacteria from infected flea feces enter the body through cuts, scratches or mucous membranes, often after contact with flea-infested animals or their environments. Symptoms typically appear one to two weeks after exposure and include fever, headache, rash, body aches, nausea and vomiting. While treatable with antibiotics like doxycycline, delayed diagnosis can lead to severe complications, explaining the high hospitalization rate observed last year.

Health officials noted that cases were reported countywide in 2025, with three localized outbreaks investigated in Central Los Angeles City, the City of Santa Monica and the unincorporated community of Willowbrook in South Los Angeles County. The disease affects people of all ages, with confirmed cases ranging from 1 to 85 years old. Many exposures happen around the home, as pets or wildlife bring fleas indoors on their fur or through yard debris.

The record numbers reflect a multi-year rise. County data show 141 cases in 2021, climbing to 171 in 2022 before a dip to 124 in 2023 and the rebound in subsequent years. Officials attribute the increase partly to abundant flea hosts — particularly opossums and stray cats — thriving in urban and suburban environments amid factors like mild winters, abundant food sources from unsecured trash and dense populations of rodents and wildlife.

Public health experts link the surge to broader environmental conditions in Los Angeles County, including challenges with homelessness, sanitation in some neighborhoods and the proliferation of urban wildlife. Fleas capable of transmitting the disease are most commonly the cat flea (Ctenocephalides felis), which readily infests pets, rodents and opossums. Animals may appear healthy while carrying infected fleas, making unwitting exposure common.

Hospitalization data underscore the illness's severity in this outbreak. Of the 220 confirmed cases in 2025, approximately 198 patients — nearly nine out of 10 — required inpatient care. All known patients recovered after antibiotic treatment, but the high rate of severe cases has strained local medical resources and raised concerns about underreporting or delayed care in vulnerable populations.

Dr. Davis and county veterinarians emphasized year-round flea prevention for pets as a key defense. Recommendations include using veterinarian-approved flea control products, keeping pets indoors when possible, storing pet food indoors and avoiding feeding or handling stray or wild animals. Residents are also urged to maintain properties by removing yard debris, trimming vegetation, securing trash in tight-lidded containers and sealing potential entry points for rodents and opossums.

Personal protection measures include using EPA-registered insect repellents labeled for fleas when outdoors in high-risk areas. Anyone experiencing fever, headache, rash or flu-like symptoms — particularly after potential flea exposure — should seek prompt medical attention and inform providers about possible contact with animals or fleas.

The announcement has drawn attention amid ongoing discussions about public health infrastructure in Los Angeles. Some residents and commentators have pointed to visible street conditions, including encampments and trash accumulation, as contributing factors that sustain flea and rodent populations. County officials have not directly linked the typhus rise to specific policy debates but stressed that prevention starts at the individual and household level.

Local outbreaks in Santa Monica, Central Los Angeles and Willowbrook prompted targeted investigations involving vector control, environmental health teams and community outreach. In past smaller outbreaks, such as a 2015 mobile home community cluster, multi-agency responses helped contain spread through education and sanitation improvements.

Flea-borne typhus has been present in Southern California for decades but remained relatively rare until recent years. Historical surveillance shows lower annual totals in the early 2000s, with cases now consistently higher. California as a whole has seen elevated flea-borne rickettsial disease activity, though Los Angeles County reports the bulk of cases.

Physicians are being reminded to consider typhus in differential diagnoses for patients with compatible symptoms, especially in endemic areas. Early antibiotic treatment dramatically reduces complications such as organ involvement or prolonged recovery. Laboratory confirmation typically involves serology or PCR testing, with results guiding clinical management.

As spring weather arrives, health officials warn that flea activity may intensify with warmer temperatures, potentially driving further cases if prevention lags. The county's public health website offers detailed guidance, maps of historical activity and resources for pet owners at ph.lacounty.gov/typhus.

Animal control agencies report increased calls about opossums and stray cats in residential areas. Wildlife experts note that opossums, while beneficial as tick predators in some contexts, can harbor fleas that transmit typhus when populations grow unchecked near human dwellings.

Community organizations and veterinarians are amplifying the message through social media and local clinics. Pet owners are encouraged to consult veterinarians for tailored flea prevention plans, as over-the-counter products may be less effective or unsafe for certain animals.

The high hospitalization rate has sparked questions about healthcare access and awareness. Some infected individuals may initially dismiss symptoms as a common virus, delaying care until illness worsens. Public health campaigns aim to raise recognition of typhus as a locally relevant threat rather than a historical disease.

Los Angeles County, with its diverse urban, suburban and rural pockets, presents unique challenges for vector control. From coastal Santa Monica to inland neighborhoods, flea hosts adapt readily. Officials stress that even well-maintained homes can see incursions if neighboring properties harbor wildlife or if pets roam.

Looking ahead, the county plans continued surveillance, community education and collaboration with vector control districts. No human vaccine exists for flea-borne typhus, making behavioral and environmental prevention the primary tools.

Residents expressed a mix of concern and resolve in local discussions. Many pet owners reported stepping up flea treatments, while others called for stronger municipal efforts on sanitation and wildlife management. Health authorities reiterated that collective action — from individual households to broader community cleanups — can curb transmission.

The record 2025 figures serve as a stark reminder that flea-borne diseases once considered controlled can resurge when ecological balances shift. With proactive steps, officials say, Angelenos can protect themselves, their families and their pets from this preventable but potentially serious infection.

As of early April 2026, no new aggregate 2026 case totals have been released, but vigilance remains essential. The Department of Public Health continues to monitor trends and stands ready to investigate any emerging clusters.

For the latest guidance, residents should visit the Los Angeles County Department of Public Health typhus information page or contact their healthcare provider with questions about symptoms or prevention.