Warnings Over Rising Flea-Borne Typhus Cases in Los Angeles County
Health officials are cautioning residents to be vigilant about flea prevention, particularly in pets, following an unprecedented surge in flea-borne typhus cases in Los Angeles County over the last year.
The Los Angeles County Department of Public Health reported that there were 220 cases of flea-borne typhus in 2025, marking a record high. The department investigated three distinct outbreaks during the year, one of which occurred in Santa Monica.
Interestingly, California has recorded the highest incidence of flea-borne typhus in recent history, with 277 cases reported statewide. This figure is more than double that from 2016, where the count included suspect, probable, and confirmed cases. It’s worth noting that while California initiated mandatory electronic reporting for the disease in 2011, the majority of cases often emerge from Los Angeles and Orange counties.
Typhus, caused by the Rickettsia typhi bacteria, manifests with symptoms such as fever, chills, headaches, and a distinctive spotted rash. The transmission occurs when infected fleas bite humans; the fleas excrete during this process, and scratching the bite can introduce the flea feces into the bloodstream. The health department indicated that these infected fleas often come from stray animals, as well as local rodents and opossums.
Dr. Muntu Davis, the health officer for Los Angeles County, emphasized the seriousness of flea-borne typhus, stating, “It can cause significant illness, but it’s preventable with simple measures.” He urged residents to take immediate action, such as regularly applying flea control treatments on their pets, steering clear of stray animals, and ensuring that wildlife doesn’t inhabit their surroundings.
Shannon Bennett, a microbiology curator at the California Academy of Sciences, remarked on the unsettling nature of encountering a disease that’s been around for centuries, expressing concerns over hygiene and living conditions that could heighten risk factors. She also linked warmer temperatures due to climate change to potential increases in flea populations, which could further facilitate the spread of typhus.
Warming climates, she noted, can accelerate flea life cycles, increase their populations, and heighten the risk of disease transmission from animals to humans as people encroach upon wildlife habitats.
Lowering the risk of serious complications, typhus is usually treatable with antibiotics, and deaths are relatively rare, making up less than 1% of cases. However, health officials pointed out that around 90% of those infected require hospitalization, underscoring the disease’s severity.
Dr. Monica Gandhi, an infectious disease expert at UC San Francisco, elaborated on the potential dangers of the illness, highlighting that severe symptoms can lead to dangerous laboratory findings, including low clotting factors and anemia, which increase the risk of internal bleeding.
Gandhi emphasized that anyone can be affected, regardless of health status or age. “Traditionally, those infected were often hikers or nature enthusiasts. Now, we see cases emerging from interactions with pets,” she remarked.
