One striking thing about the story Worker gets Covid-19, what now for his room-mates? (15 April 2020) is that the 16 room-mates of the infected worker were not immediately swab-tested for the virus SARS-Cov-2.
Instead they were confined to their room and monitored for symptoms. This seems far too passive an approach. There are reports that a person can become infectious a couple of days before he develops symptoms, Thus, waiting for symptoms to appear among the room-mates would be too late. One might already be infected, and he could infect several more people in the dorm before he develops a cough or fever and is discovered to be Covid-19-positive too.
Moreover, there is evidence that some people can get the virus and yet remain asymptomatic. There is no clear answer yet to the question of how infectious these asymptomatic persons are, but in these times, one should err on the side of caution. So, one of the room-mates may be asymptomatic, but he may be infecting several others in the meantime without the health monitors having a clue.
Thus, testing shouldn’t be reactive, only when symptoms appear, but pro-active, to see where the virus has spread to before infectiousness and transmission beome a problem.
Very few tests
The Ministry of Health’s website, on 15 April 2020, carried figures for the numbers of tests performed. Oddly, the data is for 7 April, making them one week old.
Screen shot from MOH website, accessed 16 April 2020
It says that 72,680 tests have been carried out, on 47,486 unique persons. This means that in the 74 days since the first case was discovered here on 23 January 2020, we have carried out a daily average of 982 tests on 642 unique persons. These numbers seem terribly low.
It is also rather noticeable that in the daily updates and press briefings, little is said about testing coverage.
One cannot help but wonder what’s going on about Singapore’s testing capability.
Right now, the number of cases from worker dormitories is exploding. There were 404 (out of a Singapore total of 447) reported on 15 April, a new record, and yet another record of 654 dorm cases (out of a total of 728) reported on 16 April. Our health authorities must get ahead of the curve, and not testing room-mates of positive cases, instead waiting for symptoms, seems remarkably complacent.
Maybe our testing capability is under severe strain, and if we have 654 new cases from dorms in one day (as we did on 16 April 2020), any regime that requires testing of all room-mates implies that we would need to carry out 6,500 to 13,000 tests in 24 hours — assuming 10 to 20 room-mates per infected worker.
But there are ways around that. The concept is called “pool testing”, where swabs are taken from a group of persons, pooled together as a single sample for the actual lab test. If the result comes out negative, then we can reasonably conclude that all the persons in the pool are negative. If the pooled sample comes out positive, it would then mean re-testing each person individually to see who in the pool was the positive one. Nonetheless, pool testing is a way to screen much larger numbers of people quickly. It should enable us to get a faster reading of the situation in the dorms.
Exactly as feared, the dorms are incubators
As TWC2 warned in March and in the article The risks from packing them in, the crowded conditions in dorm rooms make virus transmission particularly easy. We repeatedly urged a massive reduction in density by moving workers out into alternative accommodation, but there’s no need to belabour the point here, except to say that while there has been some dispersal, only 7,000 workers have been moved out — a figure given by Manpower Minister Josephine Teo a few days ago. This is way too few considering that there are about 200,000 workers in purpose-built dormitories and perhaps 100,000 more in other dorms.
As they are, our dorms can be compared to cruise ships, which when quarantined, are often referred to as incubators of the virus. If we need another example, the French aircraft carrier Charles de Gaulle is it. Out of about 2,000 sailors on board, 668 have so far been found to be Covid-19 positive. It had set sail on 21 January 2020 for deployment and exercises, but it is not clear which ports it had called into in the intervening period.
The numbers emerging from the dorms look like the situation is increasingly out of control. It is not even credible anymore if the authorities were to say the numbers are increasing because we’re testing more, since as the story Worker gets Covid-19, what now for room-mates? shows, even when there is an infected worker, the room-mates are not tested.
This can only mean that we’re battling the virus blind.
The old strategy isn’t working. Time for more aggressive action.
A week on, new data has been published by the Ministry of Health regarding tests. On 20 April, its website said that as of 14 April 2020, 94,796 tests have been performed on 59,737 unique individuals. Despite infection numbers rising exponentially during this period, testing numbers still do not look impressive.
If we compare the figures for 7 April and 14 April, we can see that in the seven-day period, 22,116 tests were carried out on 12,251 unique individuals. That’s an average of 3,159 tests a day on an average of 1,750 unique individuals. This seems to be Singapore’s maximum rate of swab testing going by previous reports of a capacity of 2,900 tests a day.
However, today (20 April) alone, we reported 1,426 new cases. If we manage to test only around 1,750 unique individuals a day, it appears that we really can’t be testing enough close contacts of the new cases to get ahead of the epidemic. We’re always playing catch-up and possibly falling ever further behind.