The state health department on Wednesday advised 26 passengers who were on the same flight as the 18-year-old student who has tested positive for Covid-19 to be in home quarantine, sources said on Thursday.

The 26 passengers were seated in the same row as the student and in the three rows in front and three rows behind him. A health department official said the home-quarantine advice was issued following an international protocol.

Another official said the 26 people were mostly from Bengal and Jharkhand.

A public health professional said home quarantine means the person should not step out of a room. Also, he or she should not come in physical contact with any family member.

One person wearing gloves and a face mask should deliver food to the quarantined person, who must wear a mask, too.

“The Centre has given us list of passengers who were on the same Etihad Airways flight from Abu Dhabi to Calcutta as the affected student on Sunday. From the list, we noted down the names and other details of the 26 passengers who were in close proximity to the person who tested positive,” a health department official said.

A spokesperson for Etihad Airways said they followed all guidelines. “In any case where a guest has tested positive for Covid-19 on arrival, Etihad Airways follows procedures and guidelines specified by the relevant health authorities in both countries, including assisting them in contacting other guests seated with or near the guest as a precaution. As per government guidelines, all close contact tracing for passengers will be carried out by the respective authorities,” said the spokesperson.

“Following intensive cleaning and testing, the aircraft and crew were released to return to Abu Dhabi. The safety and well-being of its passengers and crew is Etihad’s number one priority.”

The 26 passengers who have been advised home quarantine are the primary contacts of the student. According to a health department official, primary contacts are those who come within 2 metres of a Covid-19 patient without wearing any protective gear.

The student’s parents and two drivers and two help who work for the family were sent to a quarantine facility set up by the government in New Town on Wednesday.

Another official said since none of those sent to the New Town facility tested positive, there was no need to test samples from secondary contacts. People who came in touch with primary contacts are called secondary contacts.

The New Town facility — set up on the campus of Chittaranjan National Cancer Institute — had 30 people on Thursday.