Johns Hopkins Medicine is marking a milestone in its efforts to prevent the spread of COVID-19 by surpassing more than 100,000 detection tests performed.

Clinical microbiologists at the institution first developed the in-house screening test in March of this year. Since then, the Johns Hopkins Medicine microbiology lab has tested more than 100,000 patients — with more than 10,000 testing positive for the SARS-CoV-2, the virus that causes COVID-19.

In the lab, a team of about 90 staff members, including about 15 molecular microbiologists, work around the clock to process as many as 1,500 tests each day — a number that will soon double as the lab continues to add processing platforms, says Heba Mostafa, M.B.B.Ch., Ph.D., assistant professor of pathology at the Johns Hopkins University School of Medicine and co-developer of the Johns Hopkins COVID-19 test. The turnaround time for results is less than 24 hours — with a goal to reduce that time to 12 hours.

Johns Hopkins Medicine tests patients and employees with symptoms based on guidelines and criteria set by the U.S. Centers for Disease Control and Prevention and the Maryland health department. Asymptomatic patients who are admitted or will undergo surgery at health system hospitals and surgical centers also are tested.

Tests are conducted at the hospital and at designated outdoor sites on hospital campuses. Tests also have been performed in the community neighboring the Johns Hopkins medical campus in Baltimore, including at homeless shelters and nursing homes, and in the 21224 ZIP code, an area designated as a COVID-19 “hot spot.”

“There are dozens of people throughout the Johns Hopkins Health System at various sites collecting test samples,” says Karen Carroll, M.D., professor of pathology and director of the Division of Medical Microbiology at the Johns Hopkins University School of Medicine, and co-developer of the Johns Hopkins COVID-19 test. “We are all committed to ensuring we do our part to avert transmission of COVID-19.”

Mostafa and other staff members who conduct testing are available to discuss the 100,000-test milestone with the media.