Singapore pilots 'pooled testing' on nursing home staff
In its recently completed testing of all nursing home staff here, the Ministry of Health (MOH) trialled a new method which may allow it to ramp up its testing capabilities several fold.
The downside, however, is there may be a slightly increased chance of an infected person going undetected.
An MOH spokesman said it has piloted the use of pooled testing with the help of the National Public Health Laboratory and Agency for Integrated Care.
The pilot was on nursing home staff, who number about 9,000 across 80 nursing homes here. It is not known exactly how many staff members pooled testing was used on.
Singapore has done more than 175,000 swab tests for Covid-19, and is ramping up its testing capabilities to 40,000 tests daily, from its previous capacity of 8,000 daily tests.
The MOH spokesman explained that Singapore has been using the Covid-19 polymerase chain reaction test for its cases. But while this is a test with very high accuracy, it is resource intensive.
"It is a complex process requiring skilled laboratory personnel, test kits and instruments," said the spokesman. Each test is usually used on only one suspect or confirmed Covid-19 case.
With pooled testing, the swab samples of several people are mixed into one. This allows testing all of these cases as though they were one sample, and if it turns up negative, all may be considered to be free of Covid-19.
If it tests positive, then individual testing for each of the cases will have to be done to identify those infected.
Several recent studies, including one by German researchers, found that pooled testing for Covid-19 can significantly increase testing capabilities while still getting reliable results. However, some noted it was possible for positive cases to escape detection if tested in large numbers.
The MOH spokesman noted that pooled testing may be used in sub-populations with very low prevalence rates for Covid-19, or for mass screening purposes. She added that the pilot here used a maximum of five patient samples per pool.
It is not known if or when Singapore will use pooled testing for Covid-19 as the norm.