Extensive testing of the local population within a “hotspot” can ensure that infected people are identified and quarantined before they infect others. However, it is also beyond Australia’s budget and testing capacity to perform so many tests. A solution to this problem is pooled testing.
Pooled testing, as the name suggests, is the pooling together of a group of samples to run only one test[3]. For example, every week all households in one street could collect their own samples of saliva[4], mail those samples to a testing centre or deposit them in a testing bin (methods already in use for screening programs such as Bowel Cancer screening). The lab then combines together all the saliva samples from one household, or one street, or even one suburb, into a single sample for testing. In this way the number of tests required can be reduced by a factor of 10 or more.
Pooled testing makes sense where the disease prevalence (number of cases in a population at a given time) is low. If the disease prevalence is high, then most of the grouped samples will be positive, which then requires individual testing of all the individuals in that group – rendering pooled testing a useless exercise to reduce test numbers.