How do we determine whether an employee contracted an infectious disease while at work?

If an employee reports symptoms of a contagious disease that affects the public at large, the workplace might be only one possible source of the infection. In these situations, the employer must examine the employee’s work duties and environment to determine whether it is more likely than not that one or more events or exposures at work caused or contributed to the condition. If the employer determines it is unlikely that the exposure occurred in the work environment, the employer would not record the case.

In the case of Lyme disease, for example, the employer would determine a case to be work-related if the employee was a groundskeeper with regular exposure to outdoor conditions likely to result in contact with deer ticks.

For COVID-19, the employer would consider a case work-related if another employee with whom the newly infected employee had contact at work reported having the same condition. COVID-19 cases are not excepted under 1904.5(b)(2)(viii) like the common cold and flu are. However, per a March 31, 2026, OSHA enforcement memo, the agency is exercising “enforcement discretion” not to cite violations for failure to record COVID-19 cases or to report COVID-19 hospitalizations and fatalities. OSHA’s latest policy is more in line with its treatment of common cold and flu cases.