After several cases of Rocky Mountain spotted fever were reported in Southern California, the Centers for Disease Control and Prevention has issued a warning about the tick-borne illness. Five people have been hospitalized since July after being in a Mexican border city in recent months, the Washington Post reports, four of whom were under age 18. Three of them died. "This disease is extraordinarily unfortunate because half of the patients die in the first eight days of illness," said Christopher Paddock, a CDC chief medical officer. It can be treated if caught quickly.
But the early symptoms—including a low fever, headache, and gastrointestinal discomfort—often don't seem serious or unique, and the disease often isn't diagnosed in time, health officials said. It's spread by infected ticks, per CNN. Another problem, the CDC's health alert says, is that "many patients do not recall being bitten by a tick." The agency recommends health care providers look at treating anyone who's been to northern Mexico recently and has symptoms with the antibiotic doxycycline—without waiting for test results.
Rocky Mountain spotted fever usually isn't a major problem in the US, but it's endemic now in portions of northern Mexico and the southwestern US. It doesn't spread from person to person but can be transmitted in that region by brown dog ticks, per CNN. All five of the patients had been in Tecate, a city in the northern Mexican state of Baja California, within two weeks of falling ill. The fatality rate in Mexico can top 40%, the CDC said, though it's much lower in the US. (More Rocky Mountain spotted fever stories.)