Bear Creek and Creekside are located in Fairburn; Woodland is located in East Point.
The teacher felt ill at work Friday and 911 was called and the teacher was transported from the school campus to a hospital, said Looney.
Looney said the teacher had extensive contact with students and other staff, and that the schools were identifying the students and staff for the Department of Health for follow up.
MORE>> Parents wait as Fulton weighs school closures after coronavirus case
Fulton learned the teacher tested positive for the virus today at 11 a.m. and dismissed the three schools at 2 p.m..
Looney said he made the decision to close all county schools Tuesday to assess the level of risk, gather more information and reclean schools.
“As a school superintendent, the last thing I want do to is close schools,” said Looney. But he felt the closings were in the best interest of students and the community.
Gov. Brian Kemp, meanwhile, has scheduled a 4:45 p.m. press conference for an update on recent developments regarding the virus in Georgia.
Staff writer Maureen Downey contributed to this story.