Q) When was the earliest case that Ministry of Health backtracked to?

Dr Derrick Heng (MOH Group Director for Public Health Group): The (earliest) case that we know of was July 31. We would not have picked up on all the cases, (so) we would not be able to pinpoint definitively the first index case (patient zero).

Mr Koh Peng Keng (MOH Group Director, Operations): The first case we knew of was patient A (the 47-year-old Malaysian woman whose case was reported on Saturday). The rest of it we had to work with the GPs, to do a lot of tracking to try and look back.

Dr Heng: We went back to look at people who were part of the GP (cases), and (at the) construction site, the people who had reported symptoms in the past. We took samples…the samples (tested) positive sometime late Sunday night.

Mr Koh: The GP alerted us of this unusual cluster of cases with mild symptoms, it’s only (then) we went back to check….most of them had already recovered. So it was a look back…Initial hypothesis was that it was just some mild viral infection that transmits from person to person. Zika was not specifically suspected at that point when the GP was seeing this group.

Q) Saturday was confirmation that the woman (patient A) had Zika. But you had preliminary results, did you start looking before Saturday, or did you only start work on Saturday when you had confirmed results?

Dr Heng: We started preparations when the preliminary results (came out). But we had to wait for confirmation in order not to create false alarm.

Q) Patient A was at CDC on Aug 25, and it takes about three hours to do the test. So you should have known by that night.

Professor Leo Yee Sin (clinical director of Communicable Disease Centre): Her presence at CDC from the time we received her as a case, to the time she did the blood test, all this is actually a very compressed period of time, including getting her back for further assessment.

Q) The first case was announced on Saturday, and it jumped to 41 cases. Could the MOH have announced all these cases earlier?

Health Minister Gan Kim Yong: Part of the reason that we have discovered more cases is because we have now gone back to the cases that were seen before by doctors. They were not suspected to have Zika, because they have no travel history and so on. Now that we know there is a case …we’ve therefore gone back to all these cases that were surfaced before, and checked their blood tests, and that’s why we have discovered more cases, as a result of the first case. So out of the 41 cases, I think some 36 cases were a result of this active testing of the patients who were in the areas of concern, whom we felt there was the potential they would be infected by Zika. Then we went back to relook at their test results. Some were even retested to determine whether they were infected by Zika.

Q) Why did it take two days before the MOH announced patient A’s case?

Mr Gan: Some required double confirmation. So first we tested them on the urine test…various steps of testing.

Q) So it’s not like you knew about it earlier, but was keeping quiet about it?

Mr Gan: No, of course not.


The Minister and officials of the Ministry of Health provided these answers to questions from members of the mainstream press yesterday (28 Aug) afternoon. (Source: TODAY)