Multiple Deaths from RMSF in Southern CA: Cases Originated from Mexico

Adult male brown dog tick, Rhipicephalus sanguineus. Photo: CDC

Fox News, Melissa Rudy, 12.10.2023, reports on “Deadly Rocky Mountain spotted fever outbreak in California likely came from Mexico, CDC says.” The Centers for Disease Control and Prevention (CDC) issued a health advisory on 12.08.2023 advising of an outbreak of Rocky Mountain spotted fever (RMSF) southern California which has hospitalized five people and resulted in three deaths between late July and December 2023. All affected people had recently travelled to or lived in (within two weeks of illness onset) the city of Tecate, state of Baja California, Mexico. The pathogen (Rickettsia rickettsii) which causes RMSF can be transmitted by brown dog ticks (Rhipicephalus sanguineus), closely associated with domestic dogs in both urban and peri-urban settings in this region.

The CDC advises healthcare providers to include RMSF in differential diagnosis for patients with unexplained severe febrile illness that have recently travelled to northern Mexico. They also urge medical care providers to “Consider initiating doxycycline based on presumptive clinical and epidemiologic findings, and do not delay treatment pending the result of a confirmatory laboratory test. Early treatment with doxycycline saves lives.”


For More Information: 

Fox News Online Article

CDC RMSF Health Alert

Read More LDA Articles on RMSF