12/13/2023: Lab Advisory: CDC Issues Health Alert for Outbreak of Rocky Mountain Spotted Fever Among Travelers from Tecate, Mexico

CDC's Laboratory Outreach Communication System (LOCS)

Audience: Clinical Laboratories

Level: Laboratory Advisory

On December 8, 2023, CDC issued a Health Alert Network (HAN) message about an outbreak of Rocky Mountain spotted fever (RMSF) among people in the United States with recent travel to or from the city of Tecate, state of Baja California, Mexico.

If RMSF is suspected, whole blood and serum samples obtained from acutely ill people should be evaluated for Rickettsia by molecular and serologic testing methods available at commercial laboratories, state public health laboratories, or CDC.

Do not delay or withhold treatment pending receipt of laboratory test results or based on an initial negative test result. Polymerase chain reaction (PCR) amplification can be performed on whole blood, rash biopsy, or postmortem tissue but has low sensitivity early in the disease.

Serologic testing can also be performed on paired acute and convalescent serum samples collected 2–4 weeks apart. Serologic testing for detection of antibodies is frequently negative in the first week of illness. Diagnostic testing at CDC may allow retrospective laboratory confirmation in patients who die from the infection.

If Rickettsia-specific testing is not available in a jurisdiction, specimen submission to CDC can be coordinated through your state or local health department.

For more information, including recommendations for clinicians, public health professionals, and laboratories involved in specimen submission or diagnostic testing, please review the HAN in detail.

We encourage you to share this message widely with your network(s).

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Thank you,

The Laboratory Outreach Communication System

Laboratory Outreach Communication System (LOCS) | Division of Laboratory Systems (DLS)

Center for Laboratory Systems and Response (CLSR)

Centers for Disease Control and Prevention (CDC)