Measles Detection

In mid-December, the County of San Luis Obispo Public Health Laboratory (SLOPHL) performed PCR testing to confirm the presence of measles virus in a local child. The detection represented the first measles case in SLO County since 2018. No additional cases have been identified to date.

Thus far in 2025, more than 1,900 cases of measles have been confirmed in the U.S., including 49 outbreaks. Approximately 11% of patients have been hospitalized. With cases reaching the highest levels since 2000 and sustained transmission in some jurisdictions, health officials suspect that the U.S. will lose its measles elimination status in 2026.

Measles PCR testing remains a critical part of SLOPHL’s testing capabilities because it supports the rapid confirmation of cases and outbreak control efforts. This detection demonstrated that public health response acts as a key community safeguard. Additional information on measles testing can be found on the laboratory’s website.

Respiratory Illness Report

As a snapshot of the winter season, respiratory panel data from the west region showed that the common cold is outpacing influenza in both the past week and past three months. The top respiratory pathogens from the most recent week of analysis are shown below.

Seasonal influenza activity is starting to increase in both the Bay Area and Southern California. Importantly, influenza H3N2 subclade K is causing a severe flu season in the Northern Hemisphere, and this strain is expected to spread nationally. Local wastewater and test positivity trends can be found on the SLO County Dashboard.

Suspicious Letter Workup

As part of its activities as an LRN-B laboratory, the SLOPHL partners with the Federal Bureau of Investigation (FBI) to investigate potential acts of bioterrorism. In November, the FBI submitted a suspicious letter to the laboratory for workup after field testing showed no evidence of radioactive or chemical contamination. The laboratory systematically ruled out biological agents, including those causing anthrax and plague, leading to a negative determination. The investigation demonstrated the technical preparedness and dedication of laboratory staff to respond to emergent situations.

Laboratory Certification

The SLOPHL maintains laboratory certifications across three specialties—clinical (human), water, and shellfish testing. After an inspection of the laboratory facility in December, the California Department of Public Health determined the laboratory to be compliant with the Clinical Laboratory Improvement Amendments of 1988 (CLIA) and will renew the lab’s certification in clinical testing for another 2 years.

 Questions or Suggestions? 

Please contact the Laboratory Director by email or phone. 

Glen M. Miller, PhD, HCLD(ABB)

Director, Public Health Laboratory

San Luis Obispo County Public Health Laboratory

2191 Johnson Avenue, San Luis Obispo, CA 93401

(805) 781-5512

[email protected]