A Georgia couple who dressed up as Santa and Mrs. Claus for an outdoor photo session that was attended by about 50 children last week learned that they had tested positive for the coronavirus three days after the event, the county’s top elected official said on Tuesday.

The event was on Thursday and was part of an annual Christmas parade and tree-lighting ceremony in Ludowici, Ga., about 235 miles southeast of Atlanta, said Robert D. Parker, the chairman of the Long County board of commissioners.

The couple wore masks during the event at a local pavilion, Mr. Parker said, but many of the children who posed for photos with Santa and Mrs. Claus did not have face coverings, including Mr. Parker’s two children. Mr. Parker said that his children had not sat on Santa’s lap, but that he did not know whether any of the other children had done so.

Mr. Parker said that the couple, county residents whose names have not been made public, developed symptoms of Covid-19, the disease caused by the coronavirus, after the event and were tested on Saturday. The couple notified county officials on Sunday that they had tested positive for the virus, he said.