Rocky Mountain Spotted Fever ticks california
© Javier Lizarazo GuerraThe CDC revealed at least three people have died from Rocky Mountain Spotted Fever, caused by bites from infected ticks, after five cases were detected in California since July, 2023.
At least three people have died from Rocky Mountain spotted fever [RMSF] in the last five months, the Centers for Disease Control and Prevention announced in a public alert on Friday.

Five cases of the deadly disease — caused by bites from infected ticks — have been reported since July in Southern California.

In each case, the patient had been in the Mexican border city of Tecate within two weeks of becoming ill, the agency said.

All five patients, three US residents and two Mexican residents, were hospitalized and three died. Four of the patients were minors.

"RMSF is a severe, rapidly progressive, and often deadly disease transmitted by the bite of infected ticks, although many patients do not recall being bitten by a tick," the CDC notice said.

The disease is native to several states in northern Mexico along the southern border and parts of the Southwestern US.

Five cases of the deadly disease — caused by bites from infected ticks — have been reported since July in Southern California. Ladislav Kubeš

The pathogen, Rickettsia rickettsii, is commonly spread by ticks associated with urban dogs, according to the CDC.

Symptoms can at first appear mild over the first 1-4 days of infection, including a "low-moderate fever, headache, gastrointestinal symptoms, abdominal pain, myalgia, rash, and edema around the eyes and on the back of hands," the notice says.

After about five days, however, the CDC says disease can cause "altered mental status, coma, cerebral edema, respiratory compromise, necrosis, and multiorgan system damage."

Symptoms can at first appear mild over the first 1-4 days of infection, including a "low-moderate fever, headache, gastrointestinal symptoms, abdominal pain, myalgia, rash, and edema around the eyes and on the back of hands." Md Babul Hosen

Half of those who die from RMSF do so within 8 days of contracting the illness. In Mexico, the fatality rate is a staggering 40%, according to the agency.

RSMF can be treated with the antibiotic Doxycycline, which is recommended to be administered as soon as possible.