Heba Mostafa (front), director of the molecular virology lab and assistant professor of pathology at the Johns Hopkins University School of Medicine, and Karen Carroll, director of the Division of Medical Microbiology and professor of pathology at the Johns Hopkins University School of Medicine, developed a test to diagnose COVID-19.

Posted March 14, 2020

Written by Karen Nitkin

Johns Hopkins clinical microbiologists Karen Carroll, M.D., and Heba Mostafa, M.B.B.Ch., Ph.D., have developed an in-house coronavirus screening test that may soon allow the health system to test as many as 1,000 people per day.

This is important so people can learn quickly if they have COVID-19 and so doctors can test people with whom those patients came in contact.

“We will be able to diagnose more cases. This will allow the control of exposure,” says Mostafa, assistant professor of pathology and director of the molecular virology laboratory at The Johns Hopkins Hospital.

Johns Hopkins used the test, which analyzes a nasal or oral swab, for the first time on March 11, and about 85 tests were performed in the first three days.

Capacity is expected to ramp up quickly, reaching 180 people per day next week and 500 the week after that, says Mostafa. There could be 1,000 tests per day by early April, Mostafa says.

The test returns results in about 24 hours, and the doctors say they hope to shorten that time to as little as three hours.

Play Video:

New Coronavirus Testing | Johns Hopkins Medicine Johns Hopkins microbiologists have developed an in-house coronavirus screening test that may soon allow the health system to test as many as 1,000 people per day.

Increased Testing for COVID-19

Having an in-house test also reduces the burden on the state laboratory, says Mostafa, increasing testing capacity elsewhere in Maryland.

Centers for Disease Control and Prevention (CDC) testing kits, which the Food and Drug Administration (FDA) approved Feb. 4, have been scarce, slowing efforts to track and contain the virus.

On Feb. 29, the FDA began allowing academic medical centers to develop their own tests, which were fast-tracked for approval.

Mostafa says development of the test was not difficult. The hard part was getting the necessary viral genomic material or the virus to perform the validation and the reagents required to conduct the test. “Once we had everything we needed, we were able to complete the validation in a short period of time,” she says.

The test is now available at the Johns Hopkins Health System’s five Maryland and Washington hospitals.

“Testing is very important in terms of identifying cases so epidemiologists can then contact people exposed to individuals who are known to be positive and make recommendations about home isolation and further follow-up,” says Carroll, professor of pathology and director of the Division of Medical Microbiology at Johns Hopkins. “If people are infected, we want them to stay home.”

Can I get a coronavirus screening test?

Testing is available for people who have symptoms of COVID-19, such as a fever, cough or shortness of breath; and who meet other CDC criteria, including travel to countries or states that have high incidences of the disease. A physician’s referral is required.

To protect themselves and others, Carroll and Mostafa urge people to stay away from emergency rooms unless they truly need emergency care.

People who feel sick and suspect they have the new coronavirus but who do not need emergency care should call their primary care or specialty care provider, or an urgent care center, and be prepared to describe their symptoms over the phone before arriving. “We are encouraging people to call and talk to a knowledgeable health care professional,” Carroll says.

Learn more about COVID-19 guidelines for Johns Hopkins patients.