There is a reason behind every detail inside the county’s new $93 million public health lab, right down to the placement of each microscope.
It might look like the scope sitting by a window in the new building’s parasitology suite was situated to give its a sweeping view of the county’s Overland Avenue operations campus in Kearny Mesa, but lab director Jeremy Corrigan explains that the real reason goes much deeper.
“Even though you don’t feel it, buildings will vibrate enough to mess up your microscopy, because we’re looking at very minute areas,” Corrigan said. “This part of the building sits right on top of a big beam, so that’s why the microscope is where it is.
“We actually had to do a vibration study to that it was stable enough.”
And that is a common theme inside this two-story, 52,000-square-foot structure.
Though the county technically took possession of the building on April 11, it will not be fully up and running until some time in July. That is because it is filled with scientific equipment that requires much more than simple installation. The genetic sequencers, polymerase chain reaction machines, and mass spectrometers that can detect a broad range of pathogens — 40 bacteria and 15 viruses — must be validated before they can be used with samples collected from patients.
It is a painstaking process that involves running sets of test samples through newly installed equipment, then comparing it with the results from the manufacturer’s reference machines to make sure that the new gear produces matching results.
“We put in knowns and unknowns and make sure that they come out correctly, but we also challenge the systems by putting in things like the wrong type of bacteria,” Corrigan said.
The process is longest for tuberculosis, which requires samples to be cultured, grown naturally on special plates covered with nutrients, before they can be tested.
Work is also underway to bring wastewater testing, performed by a consortium of local scientific organizations, including UC San Diego and Scripps Research, in-house. Julie Tsecouras, a molecular scientist with a doctorate in entomology and a master’s degree in public health, said that she and others with the county lab have been visiting UCSD to study its wastewater protocols and how they are brought to life in the lab. It will take time, she said, to make sure that every step is the same.
“We want to ensure that we’re able to match the results that they’ve been putting out so that we can have a seamless transition,” she said.
And validation goes far beyond testing equipment. Everything, right down to temperatures sustained by the facility’s walk-in coolers and freezers, must be shown to meet specifications.
Even the trash.
Nothing that comes in with infectious agents may be thrown away until it has first been sterilized using special ovens called autoclaves that kill all microbes and viruses with high-pressure steam.
“We’re not just validating the testing process; we’re also validating the decontamination process, as well,” Corrigan said. “We have to show and prove to everybody that these things sterilize and kill all of our waste and all of our pathogens.”
And that work is especially important on the building’s second floor, which contains two special labs, each of which meets level three biosafety standards. These requirements specify extra security, non-porous surfaces, air-locked entries and exits, and negative pressure systems that pull air in rather than letting it out when doors are opened. Special filters scrub exhaust air, and tests are performed in special biosafety cabinets. Each lab is equipped with its own dedicated set of scientific instruments, including bench-top genetic sequencers, and each has its own dedicated autoclave for cleanup. Exits have their own locker rooms and showers, allowing workers to properly remove the extensive personal protective equipment they must wear while working inside.
This self-contained design is employed for the most dangerous threats. One is dedicated to identifying suspected bioterrorism agents, often white powders that may be delivered in a piece of mail that could be the deadly toxin ricin or Bacillus anthracis, the bacterium that causes anthrax.
Every few months, someone in San Diego encounters a white powder of unknown origin, and it is the local public health lab’s obligation to make a quick identification.
“We have a full set of duplicated instruments because you can’t take it out of this room,” Corrigan said.
Even culturing is performed inside, allowing lab workers to grow large enough amounts of potentially deadly bacteria to perform the required tests.
Most of the white powders brought to the bioterrorism lab turn out to pose only pantry-level threats — corn starch is a common culprit. Brucella, the bacteria that cause the infectious disease brucellosis, is the most commonly detected pathogen that makes its way here.
The second level-three lab on the second floor is dedicated to tuberculosis, a disease that used to share a common space with the bioterrorism unit. But a floor plan that’s twice as large as the one it replaces provides more space to handle testing separately.
There is also a new training lab on the facility’s ground floor. The county’s previous public health lab, located inside its Health Services Complex in San Diego’s Midway District, did not have dedicated space for training.
The building is designed top-to-bottom to cluster related activities together and to make often-sensitive work as convenient as possible. Off the building’s main delivery entrance, where samples arrive from the field, is a cooler where deceased animals are stored for examination for signs of infectious disease, especially rabies. Bats are the most common subjects, but other animals, even those as large as cows or horses, may be sent in for rabies investigations if they died for unknown reasons. The room where these examinations are performed is accessed through the cooler, meaning that the whole process can be performed, and samples collected, without bringing the animal inside the main building.
Inside, there is another special set of coolers midway down a hallway where workers can pick up the chemicals and other refrigerated supplies they need to do their work without having to enter the facility’s main central supply department, making it quicker to get what’s needed than was previously the case. It’s a convenience suggested by a lab manager.
Elizabeth Hernandez, San Diego County’s public health director, said that those kinds of touches are intentional. Those who use these spaces are deemed the best to help designers pull together plans that would produce an efficient workflow. While the facility does incorporate public art, including a giant microscope sculpture out front made by local artists Einar & Jamex De la Torre, the guiding principle was functionality.
“The public health laboratory staff had input from day one until the finishing touches,” Hernandez said. “It was developed for them to serve the community.”
The new building can do things its predecessor couldn’t. For example, rabies testing can now be handled in-house. However, the biggest gains are expected to arrive through better use of modern technology that the previous county lab possessed but could not use to its full capacity and capability.
Significant investments in genetic sequencing should allow investigators to more quickly identify the subtypes of viruses, for example, making it easier to determine where a particular pathogen came from. Such work is particularly valuable during outbreaks such as the spread of hepatitis A among San Diego’s unhoused residents in 2017. Back then, determining subtypes often meant sending samples to state labs and waiting a significant amount of time for the results.
High-volume testing is also better ed, and there is extra space to bring in additional instrumentation if the region were to once again experience a pandemic, one that required mass community testing.
Nicholas Rhoades, a microbiologist brought in to help evolve the county’s efforts in the realm of genetic epidemiology, said that the constellation of equipment and the spaces that the instrumentation occupies should mean much less need for the county to send samples outside the community, meaning quicker turnaround for disease investigations.
“Now we have the space and the tools to do the science properly,” Rhoades said. “We were trying to make the best of what we had at Rosecrans using a less-than-ideal space, and that impacts the amount of work that you can do.
“We were limited to sequencing things like COVID and foodborne outbreaks, but having this big beautiful space allows us to expand to other public health pathogens, and to do new stuff like wastewater testing, in a clean way so that we can guarantee that the results are accurate.”
Expanding the lab’s capabilities, Hernandez noted, has required hiring about 20 new lab workers, and those positions are funded through federal and state grants. The lab’s annual operating budget is $25 million. Keeping the new facility fully operational, then, is contingent upon continued funding in the future, a topic that has recently become less certain as budget cuts are under consideration.
