Typhus is a bacterial disease spread by infected fleas. Symptoms range from mild to potentially deadly. Health officials say it's so widespread, you can be at risk whether you have a pet or not. "These cases have been rising year after year. They're occurring in all areas of our county," said Medical Epidemiologist Dr. Aiman Halai with the Los Angeles County Department of Public Health. In 2025, 220 typhus infections were recorded in L.A. County, which is up from 187 cases in 2024. Halai said 90% of residents bitten by contaminated fleas ended up in the hospital.