Nassau County now has 19 confirmed coronavirus cases, including two school bus drivers, County Executive Laura Curran announced Tuesday.

“These school bus drivers, they both drive small buses,” Curran said during a press briefing. “They transport approximately 80 students on various, on several routes. Most of the families of those students have been contacted by our department of health and we’re working on contacting the rest of them.”

The positive tests on the drivers prompted officials to close public schools in Oyster Bay, Locust Valley, Glen Cove, and Westbury, and several private schools — Friends Academy, Portledge, Mill Neck Manor, Eastwood and Summit Lower School, Curran said.

The number of cases in Nassau County had nearly doubled to 13 on Monday and now spiked again.

Curran said 72 county residents have now been placed in mandatory quarantine and another 74 “in precautionary quarantine.”

She expressed particular concern over seniors, who experts say are more vulnerable to the deadly virus, and encouraged residents to take precautions while the potentially deadly epidemic continues to spread.

“Wash your hands, use hand sanitizer, do the corona bump, give the peace sign — however you want to greet people,” she said. “But let’s take a break from shaking hands for a while.”