The superintendent for East Meadow schools sent a letter to parents Thursday, warning them of a positive COVID-19 test from a student.

School officials say the student goes to W.T. Clarke High School in Westbury. The news comes just as school got underway in the area.

The release says the student was a self-reported case based on a rapid test, and that, "Based on the high percentage of false positives associated with rapid tests, we are working in conjunction with the Nassau County Department of Health to determine if this is a confirmed case."

They say if the case ends up being confirmed, the student will not be allowed to return to school for at least 14 days or after a negative test result has been provided.

Last week, a teacher in the Islip school district tested positive for COVID-19 after taking a rapid test. But just days ago, the district sent out a follow-up letter, saying the teacher went through more testing that led to a negative COVID-19 and antibody tests.

According to Dr. James Crawford of Northwell Health, rapid tests are only slightly less reliable than lab-based tests.

"The rapid testing is 98% accurate and the lab-based testing is 99% so there will be more false positives, but it's a small difference," says Crawford. "It's not that the test is bad. It's that we are in wide use of these tests, so the false positives pop up and that's hard to get used to. Our society has not had to deal with that before at this level."