Programme to detect infectious diseases like Zika set up as early as 2 years ago: Gan

Channel NewsAsia 6 Sep 16;

SINGAPORE: Authorities in Singapore have been working with general practitioners to detect infectious diseases like Zika under a surveillance programme that was set up two years ago, revealed Health Minister Gan Kim Yong in an exclusive interview with Channel NewsAsia on Monday (Sep 5).

The interview is reproduced below:

Q: MOH has been monitoring for Zika for more than a year now as part of the sentinel monitoring programme. Could you tell us a little bit more about this programme and what it aims to do?

A: As we have always expected Zika to come to Singapore sooner or later, it’s not a matter of whether it would come, but when it would come. Therefore, we have put in place a monitoring system about two years ago together with 200 GP clinics. We have also made Zika a reportable disease under the Infectious Diseases Act, so that even GPs who are not our partner GPs, they are also on the lookout for potential Zika cases, especially those with travel history to Zika-infected areas.

So over the last two years, these partner GPs of ours collected some 1,600 samples from those patients who have been to those affected areas, as well as those who have not been to these affected areas but have dengue-like symptoms, and they were tested not to have dengue and therefore we test them for Zika. And so far, all 1,600 cases were tested negative.

In addition to this system, we’ve also been working with all the GPs and all the clinics in Singapore to be on the lookout for unusual infections or unexplained trends, so that we are alerted to potential problems, including Zika. And this was actually how the first case of locally transmitted Zika was confirmed.

Q: When the local cases surfaced last week, there was some confusion over timelines and back-tracing among the general public. How did we go from one confirmed case to 41 confirmed cases the next day? Can you explain a little about how that actually works and what the point of back-tracing is?

A: Actually, this requires some explanation. It’s important to also clarify some of the misconception about the timeline of the emergence of these cases. The first case was a lady, a 47-year-old lady. She fell ill and approached the doctor on Aug 26 and we took her blood, tested it and it was confirmed on Aug 27 to be a positive case.

That was the first confirmed case of locally transmitted Zika. And on the night of Aug 27 itself, we made the announcement.

At the same time, we also had three other cases, suspect cases, results were still pending confirmation. We also made the announcement that they were preliminarily tested positive, pending confirmation.

But before that, before the first confirmed case, we had been alerted to unusual trend of infections, which they could not explain, and the GP alerted us and we have been discussing with the GP. That was on Aug 22 and once this first case of Zika case was confirmed, we decided to look back in time at the cases that emerged from this GP and to investigate further to see whether there were other cases of Zika transmission in the community.

That’s why we began to look back and we went back to the GP, took the data, contacted the patients, and we also noticed that many of the patients were construction workers. That’s why we went back to the construction site in the area, looked for the patients who were ill several weeks ago and tested them for Zika. And this all happened on Aug 27, 28 and we were able to confirm several cases of Zika - 36 of them.

And among these positive cases, we found that the first case, the earliest case that showed symptoms was Jul 31. So it did not mean that we knew about the Jul 31 case on Jul 31 and did not announce it. But because of the backward-looking test, we found that the first case started to have symptoms on Jul 31.

But the case was only confirmed on Aug 27. And that’s when we announced it the following day.

Q: Let’s come back to the sentinel programme. Could we say that the reason why the sentinel programme didn’t pick up more of these cases even before we first got to know about them, because the locations of the clinics – 200 of them – were not near where some of these clusters were developing?

A: I think one important factor that we have to bear in mind is that a lot of the Zika cases were actually asymptomatic. That means that they had no symptoms, which means that it is difficult to detect them. And those with symptoms also tend to be very mild and they also may not have travel history. So in addition to the Sentinel programme surveillance where we work with 200 GPs, we have also been working with all the other GPs, as I have mentioned, to be on the lookout for unusual trends of infection so that we can investigate further. So it is a multi-pronged approach in the surveillance system to look out for Zika as well as other emerging infectious diseases.

Q: You mentioned that a lot of these cases are actually quite mild. Do we expect more severe cases? Are there different strains of Zika we might see emerging? What should pregnant women do in the current situation? Who can they reach out to?

A: Zika is generally a very mild disease. Most of the symptoms are very mild; many of them do not have symptoms. This was the case in other countries which have Zika, and this has also been our experience so far.

Our main concern really is for pregnant women. A small number of pregnant women who infected with Zika, they may have developmental problems with their foetus, and therefore we are paying particular attention to these women who are infected by Zika.

Those pregnant women who are infected, we encourage them to discuss with their doctors, and our public hospitals will also refer them to a maternal foetal medicine specialist, so that they can provide appropriate advice.

We also have to bear in mind that not all infected patients of pregnant women will develop developmental problems with their foetus. Therefore it is important that we do counselling and support on a case-by-case basis, on an individual basis. So I would encourage these ladies to speak to their specialists, so that they can receive the appropriate counselling and support.

Q: Are you surprised that there doesn't appear to be a high number of Zika cases in neighbouring countries?

A: It’s difficult for me to comment on what happens in other countries. I would say that every country’s situation is different, the landscape is different. It is better for us to focus on Singapore, on what we can do and what we would like to do.

I think Zika is a disease that we need to come together as a people, as a government, as a society. So it’s a whole-of-government effort and a whole-of-society approach to tackling Zika. And the most effective way is to focus on vector control, where you and I can do our part in ensuring that we do not breed mosquitoes.

We eradicate all the potential breeding sites, so as to reduce the mosquito population and make transmission less easy.

Q: The idea of sequencing. Do you think sequencing work will help us in our fight of the disease?

A: I think the sequencing will allow us to have a better understanding of the disease – how it spreads and how it is transmitted and its behaviour. I think scientific knowledge is important for us to determine how best we can fight this disease. But I think it is still in early stage. There is still a lot of scientific work that needs to be done for us to better understand the virus and the disease.

- CNA