BALTIMORE (WJZ) — Thirteen Maryland hospitals are collaborating with the state health department to conduct an antibody study to determine how many Marylanders have been exposed to COVID-19.

More than 6,000 people will be tested in the initial phase.

The antibody, or serology, tests, indicate whether people have been infected by COVID-19 previously by looking for antibodies in their blood.

The test uses a blood sample to look for antibodies made in response to COVID-19 instead of looking for the virus itself.

More testing will take place based on what they learn from the initial survey.

“Understanding the level and pattern of unrecognized community transmissions of COVID-19 is crucial to curb transmission and prevent a future wave of the pandemic,” said MDH Secretary Robert R. Neall. “Establishing a baseline of those who have tested positive will help us better understand how it spreads so we can fight it more effectively.”

Participating hospitals include:

• UMPC Western Maryland
• Carroll County Hospital
• UM Shore Medical Center at Easton
• Peninsula Regional
• Frederick Memorial
• Anne Arundel Medical Center
• MedStar Franklin Square
• Johns Hopkins Health System
• Howard General Hospital
• Holy Cross Hospital
• Shady Grove Adventist
• UM Prince George’s Hospital Center
• MedStar Southern Maryland

The lab will process samples from patients who have their blood drawn during routine clinical care at the hospitals’ emergency departments/emergency rooms.

“Emergency departments are a window into communities and can reveal the state of public health. They are one of the most important resources to provide information on the prevalence of COVID-19 among all patients,” said Acting Deputy Secretary of Public Health Dr. Jinlene Chan.

“Results of the study will help state health officials refine patient surge needs and respond to additional waves of COVID-19 should they occur,” said Chief Operating Officer and Medicaid Director Dennis R. Schrader.

Aggregate results will be reported back to the hospitals for their surge planning and community health efforts.