Anne Arundel County Department of Health issued the following announcement on April 6.
Maryland Department of Health (MDH) Confirms Measles Case; Possible Exposures in Baltimore Area. MDH wants to inform anyone who visited 4000 Old Court Road in Pikesville, MD on April 2 (from 9 am to 1 pm) that they may have been exposed to measles. Individuals who may have been exposed at additional locations are being notified directly. More info. https://health.maryland.gov/newsroom/Pages/Measles-Case-Confirmed;-Possible-Exposures-in-Baltimore-Area.aspx
Original source can be found here.
Source: Anne Arundel County Department of Health