Ramping Up Testing for COVID-19

In January, before most of America had even heard of the novel coronavirus (COVID-19), clinical lab scientists and diagnostic clinicians at Children's Hospital of Philadelphia (CHOP) already had ambitious goals: to develop a diagnostic test — or tests — that would quickly and accurately identify the new virus in patients.

An initial test from the CDC existed, but when CHOP lab scientists trialed the test, “We encountered unreliable results," says Surabhi Mulchandani, MSc, MS, CGC, Director of Operations for CHOP's Lab Medicine Division. "We believed the key to containing the virus was more accurate testing."

COVID-19 research at CHOP include three primary testing avenues:

• The development of more accurate nasal swab testing, using CDC's original test as a basis
• Development of novel “breath sample" testing, based on recent malaria research
• Development of a "smell test" using specially trained dogs to sniff out disease markers.

Faster, smarter, safer

Deploying resources and abundant ingenuity, the CHOP team worked around the clock for weeks to modify the existing nasal swab test from the CDC to create its own — with impressive results. "Our test is more than 99% accurate and the results are reproducible," Mulchandani says.

In early March — just as the first cases of COVID-19 were confirmed in Pennsylvania — CHOP became the first hospital lab in the state and the second in the nation to get the federal government’s emergency authorization to begin testing patients for COVID-19 with the nasal swab test. "We created a team to work 24 hours a day, seven days a week to receive specimens and get results," Mulchandani says.

Soon, CHOP had expanded nasal swab testing to outpatients, staff and the surrounding community, including first responders, healthcare workers and children from underserved populations that did not have access to fast testing. By mid-March, CHOP was offering two drive-through COVID-19 testing sites, with support from Hyundai Hope on Wheels.

Initially, test results at CHOP were ready within 24 hours — a significant improvement from the national average at the time of two to five days. In April, results were available within about seven hours; by June, results were available in 4½ hours. In rare cases, when rapid results are needed for critically ill patients, one-hour testing is now available.

CHOP's nimble response allowed clinicians to better collaborate with families, identify exposures and provide optimal care for affected patients. "At the beginning of the pandemic in our area, we were able to test and track down secondary exposures swiftly from our patients, something the state and national government didn't yet have the capacity to do," adds Mulchandani.

By July 6, CHOP had conducted more than 18,970 COVID-19 tests on patients, staff and community members — each one another piece of the puzzle, explains Mulchandani: "With every test at CHOP, we're working to expand our understanding about this virus, how it affects patients and staff, and what we can do to help."

Another testing avenue

Parallel to the COVID-19 nasal swab testing was additional research by Audrey John, MD, PhD, Chief of the Division of Pediatric Infectious Diseases at CHOP. John has devoted much of her career to studying life-threatening illnesses such as malaria. She and her team believed they could use breath samples from patients with malaria, analyze them using a mass spectrometer and identify biomarkers of infection. The team believed they could develop a noninvasive "breathalyzer" type test that would keep children from repeated needlesticks.

Then, along came COVID-19. As the pandemic unfolded, John thought the same principles she'd applied to the malaria testing, might also support COVID-19 testing. Plus, breath sample testing would be more comfortable and less frightening than nasal swab testing for young children.

“It is absolutely clear that we need a comprehensive testing strategy,” says John. “This is the No. 1 health problem in the world right now.”

As a world leader in pediatric research, CHOP is uniquely positioned to quickly pursue novel investigative ideas. Marshalling CHOP’s research resources, John and her team have launched a study at CHOP to gather breath samples (along with saliva and urine) from patients who test positive for COVID-19. Using mass spectrometry, they will attempt to isolate biomarkers of the virus.

“We have a deep well of expertise in developing diagnostics for infectious diseases,” says John. “We also have state-of-the-art equipment in place to do this work.” A simple breathalyzer test for COVID-19 may not be far off.

Another testing option – with dogs

John and her team are also pursuing another novel testing strategy – using the breath samples collected from patients to collaborate with the University of Pennsylvania’s Working Dog Center.

Much like airport drug-sniffing dogs, the canines in this program are trained to use their extraordinary sense of smell to detect conditions like ovarian cancer in women. John believes their olfactory prowess can be harnessed to identify the presence of COVID-19.

John acknowledges that development of a vaccine for the virus in essential. But until one exists – and even after – “Ready access to fast, simple diagnostics will do amazing things for our ability to control the pandemic and re-open society,” she says.