BOSTON (CBS) – The three campuses of the Eliot K-8 School will close for a week after a person at the school was diagnosed with a presumptive case of coronavirus.

Boston Public Schools tweeted the news Wednesday evening, saying the coronavirus had been detected in “a non-student member of the school community.”

During a press conference, Boston Superintendent Brenda Cassellius confirmed that the individual – not a teacher or student – had been in the lower school, which services students in kindergarten and first grade. However, the entire campus was closed because teachers move between buildings. Cassellius said the school would be closed to do deep-cleaning “and make sure we can keep our students safe.”

Chief of Health and Human Services Marty Martinez said it’s not believed believed to be an example of community spread. “We believe it’s tied to the scenarios around travel that already existed,” he said.

Martinez said that public health nurses would be tracing the person’s contacts. “We’ve started that work today,” Martinez said. “And that’s why, out of an abundance of caution, we need the time to be able to do that legwork to make sure people weren’t exposed.”

WATCH: Mayor Walsh On Eliot School

Mayor Marty Walsh was asked about the possibility that Boston would close all the schools in the city. “We’re not ready to talk about canceling the district – canceling district-wide,” he said. However, Walsh confirmed that officials have been meeting for several months to prepare in case a school shutdown becomes necessary.

“I don’t think we’re at that point here yet,” Walsh said. “We are going to take excessive measures to make sure that our residents and the city of Boston stay safe.”

The district tweeted the closure was recommended by the Boston Public Health Commission. The district is encouraging anyone who has been in one of the three Eliot buildings to avoid public places and practice social distancing until March 20.

“Nothing is more important than the safety and well-being of our students and staff. We are in constant, daily communication with the Mayor … and public health officials as we monitor and address all concerns as this public health situation continues to evolve,” the district tweeted.

There are 730 students at the Eliot School.

As of March 11, there is one confirmed case of coronavirus in Boston residents and 18 presumptive positive cases for a total of 19 cases.