ATLANTA — A Catholic high school in Georgia switched to online learning this week after about 50 students tested positive for the coronavirus, which they may have contracted at a Halloween party hosted by a student’s family, officials said.

St. Pius X Catholic High School went fully virtual Monday and will remain so throughout the week with no extracurricular activities, news outlets reported Wednesday.

The DeKalb County school had nearly 50 positive cases as of Monday, an increase of 19 since last Friday, according to officials with the Archdiocese of Atlanta.

Archdiocesan spokeswoman Maureen Smith said the school was performing contact tracing to determine who can return to school Monday.

Smith said the school is assuming a “bulk” of the cases came from the Halloween party.

School President Steve Spellman said 80 students, mostly sophomores, were at the student’s house for the party. Spellman said there have been reports of other large gathering involving juniors and seniors but most of the cases have been sophomore students.

“The brief enjoyment of some has created hardship for all,” Spellman said. “Please know that this is not a political or ideological undercurrent or a subject of debate, but one of pure caution to protect our 1,100 students and 150 faculty and staff.”

The school was closed Monday and Tuesday at the direction of the Health Department and the Archdiocesan COVID Task Force.