CHICAGO (CBS) -- A total of 511 members of the Chicago Police Department have now reported positive tests for COVID-19.

Of those members, 508 have had their diagnoses confirmed by the department's Medical Section, while three have not yet.

In an internal email, Supt. David Brown again reminded all members of the department that they must wear department-issued surgical masks and gloves.

"It is recommended that surgical masks and gloves are to be worn even when inside of a police facility or department vehicle, when 6 feet of social distancing cannot be maintained," the email stated.

So far, hundreds of officers have recovered from the disease, and have returned to duty.

Three police officers have died of COVID-19: Officer Ronald Newman, Sgt. Clifford Martin, and Officer Marco DiFranco.