Deadly Rocky Mountain spotted fever outbreak in California likely came from Mexico, CDC says

An outbreak of Rocky Mountain spotted fever (RMSF) in southern California has led to three deaths, according to a Dec. 8 health advisory from the Centers for Disease Control and Prevention (CDC).

The total of five reported cases all involved affected people who had recently traveled to or lived in the city of Tecate in Mexico.

All five of the patients had been in Tecate within two weeks of becoming ill. 

They were all diagnosed in southern California hospitals between July and December 2023.