One in five confirmed coronavirus patients here went out despite being unwell, said Health Minister Gan Kim Yong yesterday.
One in four also consulted more than one doctor, he said at a press conference, giving an update on the Covid-19 situation.
Urging Singaporeans not to go out or doctor-hop if they are unwell, he said: "I am very concerned that many of the locally transmitted cases resulted from the socially irresponsible actions of a few individuals who continued to go to work, and attended events, and participated in activities despite being unwell, and went on to spread the disease to their family, friends and other contacts."
About 35 of the 160 earlier confirmed cases did not minimise social contact despite developing fever or respiratory symptoms, or consult a doctor early when unwell.
More than a fifth continued to work or carried on with their daily routine despite being sick.
The dinner at Safra Jurong, for example, was attended largely by seniors who took part in singing classes and activities like line dancing and qigong at some community clubs and residents' committee centres.
Many were in multiple groups across the island. One person who was unwell attended the event on Feb 15 and later tested positive for the coronavirus.
This could have led to 18 additional cases that were also at the dinner and later tested positive, Mr Gan noted.
Of the 18, 10 continued with daily activities despite feeling unwell, spreading the virus to another 17 people who were not at the dinner.
Meanwhile, the Wizlearn Technologies cluster had three staff members who continued with their daily activities despite feeling unwell. One of them spread the virus to a family member who also continued with daily activities while ill.
This resulted in an extra four cases that did not work for the company.
Approximate number of earlier confirmed cases that did not minimise social contact, or consult a doctor early, despite developing fever or respiratory symptoms.
Mr Gan also said that of the confirmed cases, 38 had gone to more than one general practitioner.
In fact, eight of the 38 visited three or more GP clinics.
The minister urged the public to refrain from doctor-hopping so that the same doctor can follow up on each case, and make the appropriate assessment if a patient needs to be tested for Covid-19.
Separately, the Ministry of Education said yesterday that the student passes of two international students will be terminated for breaching 14-day leave or stay-home rules.
One is an international postgraduate student at Nanyang Technological University's National Institute of Education (NIE), who breached his stay-home notice repeatedly and provided false information on his movements to the institution and NIE's board of discipline.
The other, a National University of Singapore international exchange student, was found to have breached the requirements of her leave of absence and made a false travel declaration to the university.