Essential workers who are required to continue reporting to work physically have been left wondering whether or not employers are required to report coronavirus cases to their employees. The CDC encourages employers to tell employees if they have been in contact with someone who has tested positive. However, this recommendation is not enforced by the Occupation Health and Safety Administration. That being said, workers can sue their employer for reckless endangerment or negligence should they contract the virus in the workplace.
See "Labor rights during the coronavirus ", Juliana Feliciano Reyes, The Philadelphia Inquirer , April 21, 2020