Deadly flea-borne illness hits record levels… as experts warn of serious disease that hospitalizes 90% of patients

The number of flea-borne typhus infections in Los Angeles County has hit an all-time high, with officials scrambling to contain outbreaks in several neighborhoods.

Public health data reveal that 2025 saw a staggering 220 confirmed cases of the bacterial disease, eclipsing the previous high of 187 cases just one year earlier. The trend marks a troubling escalation in a disease that was once considered rare in the region.

Of those infected last year, nearly nine out of every 10 patients required hospitalization, indicating that typhus is far from a mild illness. 

Symptoms of flea-borne typhus typically appear one to two weeks after exposure and include a high fever, severe headache, chills, body aches and a rash on the chest, sides or back. 

Anyone who experiences these signs should contact their healthcare provider immediately, as early diagnosis is critical to avoiding severe illness.

Death from flea-borne typhus is uncommon but has occurred. In 2022, three adults with underlying health conditions died from the disease in Los Angeles County. 

The disease is highly treatable with antibiotics, particularly doxycycline. Early diagnosis is the single most important factor in preventing potentially deadly illness. If caught early, most patients recover without complications. 

Typhus is caused by the bacterium Rickettsia typhi, which spreads through infected flea feces. Fleas pick it up by biting rats, stray cats or opossums, and humans get infected when the feces enter a cut, scrape or the eye. 

Health officials have identified three specific hot spots where outbreaks occurred in 2025, including central Los Angeles, coastal Santa Monica and the unincorporated neighborhood of Willowbrook near Compton. However, cases have been reported throughout the county.

Pet parents face urgent risk. Infected fleas hitch rides indoors on dogs and cats. While pets may not get sick, those fleas can bite humans or leave infected feces on furniture. 

Typhus can affect people of all ages. The age range for those infected in 2025 was from one year old to 85. 

Anyone, regardless of age or health status, can contract the disease if exposed to infected fleas.

However, certain populations face a significantly higher risk. 

People who live outdoors, whether unsheltered or in housing infested with rats or other rodents, are particularly vulnerable, according to the Los Angeles Public Health Department.

The same goes for people who work with stray animals or work in rodent-infested environments.

Warmer weather likely drove the spike. Typhus peaks in late summer and fall, when fleas reproduce more quickly, and 2025’s extended warm season pushed cases to record levels. 

The record case count is not entirely unexpected. Looking back at recent years, the trajectory has been moving upward. 

There were 141 recorded cases in 2021 in Los Angeles County rising to 171 in 2022. A slight dip occurred in 2023 with 124 cases, but the numbers surged again in 2024 before breaking the record in 2025.

While no deaths were confirmed in 2025, the high hospitalization rate indicates to public health experts that the infection is more than a minor concern.

Because symptoms overlap with many other illnesses, diagnosis can be delayed unless patients mention potential flea exposure to their doctors.

Dr Muntu Davis, Los Angeles County Health Officer, said: ‘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.’

Officials offered some straightforward advice for people to follow to prevent infection. Avoid brushing against or handling stray animals, especially those that appear sick or disheveled.

When hiking or spending time in brushy areas, wear long pants and socks and consider using insect repellent labeled as effective against fleas, and always wash hands thoroughly after any contact with animals or outdoor surfaces where rodents may roam.

For pet owners, vigilance is the first line of defense against the disease-causing bacteria. Veterinarians recommend using vet-approved flea control medicine in your animals all year round, not just during the warmer months.

This includes topical treatments, oral medications and flea collars. Regular grooming and bathing of pets can also help spot a flea problem before it becomes a full infestation.

Inside the home, frequent vacuuming of carpets, rugs and upholstered furniture removes flea eggs and larvae before they mature into biting adults.

Vets also recommend paying special attention to areas where pets sleep. Washing pet bedding weekly in hot water is another simple but highly effective measure.

Outside the home, keep the yard free of tall grasses, brush piles and accumulated leaf litter where rodents like to hide. Seal any cracks or openings in the home’s foundation, walls or roof that could allow rodents to enter.

Open or overflowing trash bins attract rats, opossums and stray cats, all of which can carry infected fleas. Ensure all garbage bins have tight-fitting lids and never leave pet food or fallen fruit from trees accessible to wildlife overnight.

Public health officials emphasize that while the record numbers in Los Angeles County are concerning, typhus is preventable and treatable. Simple daily habits can dramatically reduce the risk to the public.