Dec. 9 (UPI) -- The Centers for Disease Control and Prevention has issued an alert for Rocky Mountain Spotted Fever after at least five U.S. residents have contracted the disease since July following travels to Mexico.
The CDC described RMSF in an alert issued Friday as "a severe, rapidly progressive, and often deadly disease transmitted by the bit of infected ticks."
The health agency says that while the disease is commonly associated with tick-born transmission, many of those infected do not recall being bitten.
"RMSF is endemic across northern Mexico and areas of the southwestern United States," the CDC said.
All of the patients had either travelled to, or previously resided in, the Tecate area of the Mexican state of Baja California, within two weeks of manifesting symptoms.
All five U.S. cases were identified in southern California and all but one of the patients were minors. Three of the people who fell ill with the sickness died, according to the CDC.
The agency is advising people to check themselves, as well as their pets and children, for ticks.
The CDC urged health care providers to administer treatment with the antibiotic Doxycycline and for doctors to consider an RMSF diagnosis in patients who have recently traveled to northern Mexico if they develop "unexplained severe febrile illness.
"Consider initiating Doxycycline based on presumptive clinical and epidemiologic findings, and do not delay treatment pending the result of a confirmatory laboratory test," the CDC said. adding, "Early treatment with Doxycycline saves lives."