Veterinarian alumna helps solve deadly mysteries for the CDC

In helping to identify the source of four cases of melioidosis, Capt. Jennifer McQuiston (B.S. '93, DVM '97, M.S.' 98), an epidemiologist with the Centers for Disease Control and Prevention (CDC), was part of the team that stopped the spread of the disease that left two people dead.

Perhaps the last place one would expect to find a deadly disease is in a lavender-and-chamomile scented aroma spray bottle adorned with gemstones. When four cases of melioidosis broke out in the first half of 2021, killing two people in the U.S., experts were stumped. How were these strange bacteria, most commonly seen in Thailand, Malaysia, Singapore, and Northern Australia, finding their way into the homes of people in Georgia, Kansas, Minnesota, and Texas? Thanks to McQuiston's expert team at the CDC, the mystery was solved late last year with the source of the bacteria traced back to a most unlikely suspect — air freshener. 

Melioidosis is a tropical disease caused by the bacteria Burkholderia pseudomallei, resulting in non-specific symptoms such as cough, shortness of breath, and nausea. The bacteria can cause severe respiratory and neurologic illness and is considered dangerous enough to be a select agent that could potentially be used for bioterrorism. Because there's little tropical about the U.S. (outside of Hawaii, southern Florida, and U.S. territories in the Carribbean) and none of the infected Americans had done any international travel, the source of the bacteria was puzzling. Though two patients recovered, two others died, which made finding the carrier of the bacteria a time-sensitive matter of life and death. 

As deputy director of the division that deals with melioidosis, McQuiston helped oversee the investigation and worked with a team of experts that included laboratory scientists, epidemiologists, and health communicators. Because melioidosis thrives in warm, wet environments, the CDC worked with state health departments to find the source, testing hundreds of personal care products like lotion, soap, hand sanitizer, and food items. After testing many specimens and not finding the source of the bacteria, it looked like the investigation was coming to a dead end. 

"For me, the most frustrating part was when the Georgia case was diagnosed," McQuiston said. "This was case No. 4, and we still didn't know the cause of the outbreak. It was heartbreaking because you knew a family had just lost a child, and we were worried that more people could still be infected without an identified source. But it was also a new opportunity to visit the home in a timely way and try again to find the source of the outbreak. Our CDC team was determined to keep at it until we had an answer."

As a last attempt to solve the mystery, the CDC team returned to the most recent patient's home and found a sample they hadn't collected the first time. When the results came back, their instincts proved correct. Burkholderia pseudomallei was found in Better Homes & Gardens Lavender & Chamomile Essential Oil Infused Aromatherapy Room Spray with Gemstones. The product has since been recalled, and there have been no new cases of melioidosis. Though the outbreak is over and the immediate risk is contained, McQuiston's team is still testing hundreds of recalled specimens and working with the manufacturer and Consumer Product Safety Commission to understand how the contamination occurred.

"Behind every great accomplishment at CDC is a team of people, all working together to help solve a complex puzzle," McQuiston said. "As the deputy director for the division managing this outbreak, I was privileged to help steer the direction of the response. My role on the team was in a leadership capacity and also helping communicate with partners and the public. It can be tempting to attribute the success of the outbreak to the name you see in the newspaper, but in serving as a spokesperson for the larger team, I am hopefully able to tell all of our stories."

Stories of grand heroics rarely involve air fresheners adorned with gemstones, but McQuiston's does. Her team's work on this CDC investigation stopped melioidosis from spreading further, preventing sickness and death on an unknown scale. McQuiston's achievement is a highlight of 2021, adding her to the ranks of Virginia-Maryland College of Veterinary Medicine (VMCVM) alumni who are doing groundbreaking work that protects and serves communities. 

"My time at VMCVM was where my interest in public health was first sparked and nurtured. I credit Dr. Kevin Pelzer for that early interest in outbreak investigations and encouraging me to pursue this as a career," McQuiston said. "While at VMCVM, I also completed an M.S. in molecular biology under Dr. Tom Inzana. My time working in the laboratory gave me the skills needed to understand and value laboratory work at CDC. For this outbreak, the CDC laboratory scientists worked heroically to test hundreds of unusual and complicated samples. And ultimately, their ability to connect the cases to the products through whole-genome sequencing was what solved the puzzle."