Medical Laboratory Professionals Week 2024, from April 14 through April 20, is a time to celebrate the dedicated MHD employees who play a crucial role in safeguarding the health and well-being of our communities through innovative monitoring and testing.
The City of Milwaukee Health Department Laboratory (MHDL) may not be on the tip of everyone's tongues when discussing community health, but for 150 years, it has quietly been a cornerstone of Milwaukee's well-being. Established in 1874 as Milwaukee's first chemistry and microscopy laboratory, MHDL found its permanent home in the Zeidler Municipal Building (ZMB) in 1959.
Spread across the second floor of ZMB, the lab houses rows of state-of-the-art testing equipment, operated by a dedicated team of 27 laboratory professionals and scientists. These MHDL employees cover a wide spectrum of disciplines, from monitoring water quality at city beaches to collaborating with healthcare partners on STI testing and analyzing home samples for lead levels.
Among these professionals is Beth Pfotenhauer, MHDL’s Senior Virologist. A seasoned member of the MHDL team, who’s been with the department since 2015, Pfotenhauer says she and the rest of MHDL’s roles are pivotal in the intricate web of public health surveillance and testing.
“I’m the person who receives the sample and informs the nurse or the doctor what the sample has in it,” explains Beth. “‘Does it have flu? Herpes? HIV?’ Then the doctors and nurses take it from there.”
Pfotenhauer explains their responsibilities extend beyond individual diagnoses. In addition to working in tandem with health department programs, MHDL collaborates with external agencies, like UWM’s School of Freshwater Sciences, the Wisconsin Department of Health Services (DHS), and the Centers for Disease Control (CDC).
“In public health, we serve our immediate clients and we also receive a whole bunch of data from outside locations. We can give information to our epidemiologists to say, ‘Here’s what the state of the city is in regards to respiratory illness pathogens, in this season, in this week,’” Pfotenhauer said. “We share that data with the CDC, then that goes to the national surveillance projects to look at things like which influenza strains are going on right now.” She says MHDL is part of the national flu surveillance team, which means Milwaukee flu test results processed in MHDL have a direct influence on flu vaccines across the U.S.
“The flu samples that we get and report on help determine what the next year’s vaccine is going to be. So that’s pretty cool to hear people say they got the vaccine and know we’re a part of that network of people that helps determine what they got,” Pfotenhauer said.
MHDL is no stranger to national events and exposure. During the 1993 Milwaukee cryptosporidium outbreak, Pfotenhauer says MHDL assisted the Environmental Protection Agency [Pfotenhau1] in developing a test to detect future outbreaks nationwide. Similarly, during the 2009 Swine Flu outbreak, MHDL’s use of cell cultures for testing helped the CDC to adapt and update influenza testing for labs across the country. 
Of course, the most recent national event Pfotenhauer relates MHDL to is COVID-19. During the pandemic, MHDL collaborated with the Milwaukee Metropolitan Sewerage District (MMSD) to begin testing wastewater SARS-CoV-2. Pfotenhauer describes this task as daunting due to the complexity of testing environmental matrices like wastewater which contain various contaminants.
“Most equipment and tests have been honed to be able to test somebody’s saliva for bacteria or viruses. But when you’re looking at environmental matrices, like dirt and water, that’s a very broad category to be testing from. Wastewater has everything in it. To be able to pinpoint SARS-CoV-2 genome which degrades really quickly, and then identify the levels, amidst all of the noise and mess of everything else that’s in wastewater, that takes really great precision,” said Pfotenhauer.
“A lot of quality control and gauges are involved to make that number meaningful.”
Between 2020 and 2022, MHDL processed over 45,000 COVID-19 tests. In order to handle the sheer volume of weekly tests coming into the lab, Pfotenhauer said they had to adapt quickly.
“As COVID developed, people in the lab were able to expand rapid testing. One of my coworkers spearheaded the placement of a rapid test machine that offered test results in 15 minutes. We trained first responders to run this COVID test for all City of Milwaukee employees,” Pfotenhauer said. “I’m proud of the education and the direction the health department had. It prepared everybody and had the right people in place to make sure there was immediate coverage.”
Today, MHDL’s results are available to the public in real time. In January 2024, in partnership with MMSD, MHDL launched an online wastewater testing dashboard that shows current levels throughout Milwaukee County.
Most of Pfotenhauer’s colleagues hold degrees in chemistry or biology, with some possessing masters or PhDs. When asked if she thinks MHDL employees are the smartest in the health department, Pfotenhauer laughed off the question, joking they may be better at math. She mostly reflects on their dedication during the pandemic.
“COVID was stressful. You prepare for something like this, but you never expect it to be as big as it comes out to be. My coworker and I joke that, ‘OK, we’ve done our service to the world. If another pandemic comes out, we’re done, we’ll go be janitors.’ But then MPOX came we’re like, ‘OK, I guess we can do this one too.’ I think if another one comes up, we’ll be ready,” Pfotenhauer said.
Moving forward, MHDL remains committed to collaborating with the Community Health and Environmental Health departments, processing tests for STIs and lead poisoning. In 2023, MHDL processed over 47,000 STI tests and more than 11,000 lead tests, nearly doubling the number of tests it performed in 2022.
Looking ahead, Pfotenhauer is anticipating MHDL’s role in the Republican National Convention. MHDL will work alongside federal partners like the FBI, CDC, and Department of Homeland Security to keep the city safe from potential bio-terrorist attacks. Pfotenhauer said she also looks forward to showcasing MHDL’s sequencing capabilities, aiming to train MHD epidemiologists on sequencing technology to help trace the origin of illnesses.
“For my colleagues within the lab, I would say to give yourselves a pat on the back,” said Pfotenhauer. “We did a good job, we’re still doing a good job, and we’re supporting the health department at a really high caliber.”
As MHDL continues to innovate and adapt to evolving health threats, its commitment to accuracy and precision remains steadfast. From pioneering wastewater testing during the pandemic to providing rapid diagnostics services for STIs, the lab’s contributions are invaluable in safeguarding public health. MHDL’s work not only informs individual diagnoses but also shapes public health policy and interventions, ultimately contributing to a healthier and safer community for all.