Fewer than 20 Princeton University students are being required to self-quarantine to prevent spreading the 2019-novel coronavirus as of Feb. 3, according to Princeton University officials.

The virus originated in Wuhan, China and has spread to several countries, including the United States.

There had been as many as 108 students, both undergraduate and graduate, who had been self-quarantined over the past weekend, but new guidance issued by the New Jersey Department of Health on Feb. 2 has led to a significant decline in the number of students who are being required to self-quarantine, said Princeton University spokesman Ben Chang.

“We expect (the number of students who are self-quarantined) to decline further as we continue assessing the risk of students,” Chang said.

Based on the latest New Jersey Department of Health guidelines, students have been determined to fall into three categories – low risk, medium risk and high risk. University Health Services has been assessing the exposure risk of each person who has been placed in self-quarantine, Chang said.

“Individuals who are determined to be at low risk are not required to self-quarantine. We expect most of our students to fall into that category,” he said.

“The university will continue to support individuals who choose to self-quarantine, (but) those at low risk may resume all activities, including classes and events,” Chang said.

Persons who are deemed to be at low risk are those who have recently traveled to mainland China, including Wuhan City and Hubei Province, and who have not had any close contact with anyone confirmed to have 2019-novel coronavirus, according to the New Jersey Department of Health.

Persons who are considered to be at medium risk are returning students or workers who worked as laboratory staff either in a healthcare facility that was treating patients who were confirmed to have the virus, or who were working with the virus in a research laboratory setting without wearing the recommended personal protection equipment, or without standard biosafety precautions in place.

High risk persons are returning students or workers who have been in close contact with a person confirmed to have contracted 2019-novel coronavirus while the person was symptomatic; who had any contact with infectious secretions; or living, caring or visiting someone with a person confirmed to have the virus – regardless of the use of personal protective equipment.

Close contact is defined as being within 6 feet of someone for more than 10 minutes who has the virus, according to the New Jersey Department of Health.