The quarantine has ended for 18 people who came into close contact here with a Nigerian man infected with monkeypox.
The remaining four are expected to be released next week after 21 days of quarantine if they continue to show no symptoms, the Ministry of Health (MOH) told The Straits Times yesterday.
It added that the last person is scheduled to complete the quarantine next Tuesday.
The 38-year-old Nigerian patient, however, is still hospitalised at the National Centre for Infectious Diseases (NCID). He is believed to be recovering.
He arrived in Singapore on April 28 to attend a workshop, and started showing symptoms of fever, muscle ache, chills and skin rash on April 30.
He spent most of the intervening period in his hotel room, before being taken by ambulance to Tan Tock Seng Hospital on May 7.
He was diagnosed the following day with monkeypox - an infection that has been likened to chicken pox or a milder version of smallpox - and placed in isolation at the NCID.
He told the authorities that he may have contracted the disease after eating bush meat at a wedding in Nigeria.
The ministry then traced all the people he had been in close contact with and had them quarantined - except for one foreigner who had already left the country.
The MOH said Singapore will pick up the entire bill for the treatment and quarantine of the monkeypox victim and the 22 people.
They have Wi-Fi at their place of quarantine and meals are delivered to them.
The MOH told The Straits Times: "Given the public health objectives, the costs incurred from the use of the designated quarantine facility, assessment at NCID and post-exposure vaccination will be borne by MOH."
Most of the people quarantined had attended the same workshop as the victim. The 18 foreigners are from Britain, India, Ireland, Malaysia, Nigeria and Vietnam. The other four, who are local, have been quarantined at home.
They have all been given the smallpox vaccine, which is 85 per cent effective in preventing infection if given before or up to four days after exposure.
Singapore is the fourth country in the world outside of Africa, and the first in Asia, to have a case of monkeypox.
The infection is usually transmitted by infected animals. Human to human transmission is less common. For most people, the disease is self-limiting and patients recover in two to three weeks.
The MOH said it has advised all medical practitioners to remain vigilant against possible imported cases of monkeypox. Healthcare workers have also been advised on the management of the disease.