St. Andrew the Apostle School, a Catholic school on the West Bank, was shut down, cleaned and disinfected Tuesday after more than 80 sick teachers and students did not show up Monday.

“Out of an abundance of caution, the pastor and leadership of St. Andrew the Apostle School made the decision to close the school (Tuesday),” the Archdiocese of New Orleans said in a statement. “The decision was based on the number of students and faculty who were out sick (Monday) and would not be able to return to school (Tuesday).”

Some 70 students and 12 faculty of the school called in sick Monday, the archdiocese said.

With the school closed Tuesday, maintenance staff cleaned and disinfected various surfaces, including desks, inside the school building.

St. Andrew is expected to reopen Wednesday. It includes students in prekindergarten through seventh grade.

It is not clear what illness has afflicted the students and staff.

Louisiana state epidemiologist Raoult Ratard said the state Department of Health and Hospitals is attempting to contact and test some of the people reported to have fallen ill. But that task was made more difficult when the school shut down before informing the department of the possible outbreak, Ratard said.

Usually, he said, a school, nursing home, prison or other place with a large population held in close quarters will alert the Health Department at the first sign of an outbreak so it can have easy access to affected people for testing and treatment.

In a “simple oversight,” St. Andrew did not do that, but the school is cooperating with the department going forward, Ratard said.

An anonymous tipster notified DHH of the sick students and teachers and the school’s closure, he said.

“Hopefully, we are going to find a few people that have some symptoms, and we can try to collect some swabs,” Ratard said. The Health Department should have results of those tests within 12 hours, he said.

Schools are highly susceptible to an outbreak of contagious respiratory illnesses, such as influenza, that a person can contract by inhaling respiratory droplets expelled during a sneeze or cough or by touching an object exposed to the virus.

Such outbreaks, particularly of the flu, are not uncommon in schools, Ratard said. But they usually come later in the cold and flu season, he said.

According to the Centers for Disease Control and Prevention, flu activity usually peaks in the United States between December and February, but it can begin as early as October and extend into May.

The Health Department has not received any reports of multiple cases of sick people at other schools in the area, Ratard said.