Los Angeles is experiencing a significant rise in flea-borne typhus cases, a bacterial illness transmitted by fleas from infected rats. Since 2009, the number of typhus cases in the county has increased by 2,300%, reaching record highs in recent years. Public health officials acknowledge they are struggling with insufficient resources to manage the escalating situation.
The spread of typhus is linked to several factors, including a growing rat population, inadequate waste management, a homelessness crisis, and restrictions on rodenticides. Rats, feeding on trash, become hosts for infected fleas, which then bite humans, causing illnesses that can range from mild to fatal.
Surge in Cases and Historical Context
In the early 2000s, Los Angeles County typically recorded only a handful of flea-borne typhus cases annually. However, 2018 marked a turning point, with multiple localized outbreaks. That year, 109 cases were reported countywide, a new record, with many requiring hospitalization and disproportionately affecting individuals experiencing homelessness.
One notable case involved a city deputy attorney who contracted typhus, attributing her illness to unsanitary conditions outside City Hall East. Subsequent investigations revealed vermin infestations at municipal buildings.
By 2022, the county saw 171 cases, and its five-year average for typhus cases had doubled. The year also saw three typhus-related deaths, the first documented fatalities in decades. Records continued to break, with 187 cases in 2024 and 220 in 2025. In the latter year, approximately 90% of typhus patients required hospitalization.
Contributing Factors and Pest Control Challenges
Los Angeles was named America's rattiest city by pest control company Orkin in 2025, the first time a city other than Chicago held the top spot since the list's inception. Experts suggest the rat population has increased and become more aggressive, potentially influenced by changes in urban environments following the pandemic.
Compounding the issue, the LA County Department of Public Health stated that the increasing volume of typhus cases is "quickly exceeding capacity to investigate and respond" and that the department receives "no funding specifically for flea-borne typhus related activities."
Further complicating pest control efforts, California has enacted legislation restricting the use of certain rodenticides. Governor Gavin Newsom signed AB 1788 in 2020 and AB 2552 in 2024, measures intended to protect wildlife but which critics argue have made urban rat control significantly more difficult.
Recent Incidents and Ongoing Concerns
Recent events highlight the persistent nature of the problem. In March, concerns were raised about a large rat population at an abandoned building. In June, a fire at a warehouse in Boyle Heights led to complaints of overwhelming odors and a significant rat infestation, prompting Mayor Karen Bass to declare a state of emergency. Another outbreak was reported in the Pico-Union neighborhood, resulting in hospitalizations.
These recurring incidents underscore a broad challenge for the county in managing its urban environment, rodent population, and the public health risks associated with diseases like typhus.