Lab Matters Summer 2025 | Page 37

INFECTIOUS DISEASES

By Brandon Bonin, DrPH, MS, HCLD( ABB), director, Santa Clara County Public Health Laboratory; Krishna Surasi, MD, MPH, assistant public health officer, Santa Clara County Public Health Department; Denise Lopez, DrPH, MS, HCLD( ABB), director, Tulare County Public Health Laboratory; Lisa Seliskar, supervising public health microbiologist, Tulare County Public Health Laboratory; Elizabeth Toure, MPH, senior specialist, Infectious Diseases; and Susan Trow, PhD, senior specialist, Infectious Diseases

including the need to blaze their own trail for milk testing before federal protocols were available.

“ It’ s a big response for a small laboratory,” admits Brandon Bonin, DrPH, MS, HCLD( ABB), director of the Santa Clara County Public Health Laboratory. However, supportive and forwardthinking leadership, communication with CDC and drawing on their COVID-19 pandemic surge testing experience all enabled their success.

Lessons Learned and Looking Ahead

Santa Clara County team members( from l to r:) Laboratory Director Brandon J. Bonin, Senior Public Health Microbiologist Melanie Diep, Public Health Microbiologist Hailey Chua, Senior Public Health Microbiologist Syeda Iqbal, Public Health Microbiologist Douglas Medrano and Assistant Laboratory Director Rensen Khoshabian. Photo: Daisy Moreno.

The avian influenza A( H5N1) virus infecting wild birds around the world spread into uncharted territory this past year, impacting not only the nation’ s poultry industry but also dairy cows. The evolving outbreak underscores the importance of rapid detection, effective surveillance and collaboration – with public health laboratories playing a central role. California, with its vast agricultural landscape, has acutely felt the effects of the outbreak.

Local Laboratories Respond

California’ s local public health laboratories, spanning urban centers to rural communities, have been essential to timely detection and response throughout the state. The Tulare County Public Health Laboratory( TCPHL) was thrust into the response, quickly establishing testing protocols to monitor agricultural workers with occupational exposures. While diagnostic testing for influenza typically involves respiratory specimens, this outbreak has primarily manifested as conjunctivitis in human cases.

“ When the first dairy herd tested positive in our county, our laboratory did not yet have conjunctival swabs verified for the [ US Center for Disease Control and Prevention’ s( CDC’ s)] influenza H5 assay, due to a lack of human specimens available in California,” recalls Denise Lopez, DrPH, MS, HCLD( ABB), director of TCPHL.“ APHL connected us with Michigan Department of Health and Human Services Laboratories. They provided enough material for us to get this sample type verified and start testing within a few days.”

Santa Clara County focused on the most actionable data for their more urban population. They refined a three-pronged strategy of subtyping as many influenza A positive specimens from healthcare facilities as possible, testing retail raw milk and testing specific populations of sick cats( which are also susceptible to the virus). They faced challenges,

The successes of these California local public health laboratories come with lessons learned that can inform future preparation.“ Scaling up pre-analytic and post-analytic processes can be just as challenging as testing capacity,” notes Lisa Seliskar, supervisory molecular biologist at TCPHL. For TCPHL, piloting changes to specimen collection or test ordering with select submitters before broader implementation was key to reducing mistakes and reporting delays. Other aspects of TCPHL’ s standard specimen submission process proved beneficial for outbreak response. For example, they provide submitters with a commercial reagent that inactivates pathogens and preserves nucleic acids. This allows patient swabs that test positive by rapid methods to be reused for molecular testing at TCPHL.“ There’ s no need for a second swab to be collected … this greatly improved sample submission for our influenza surveillance,” Lopez highlights.

Effective submitter collaboration is also a theme for Santa Clara County, which emphasized the value of communicating with hospital submitters on a laboratory director to laboratory director level.

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