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by beachy
1759 days ago
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I agree, elimination still looks a good strategy, it's too early to give it up yet. If we can punch out the current outbreak (I'd put money on it, but not too much) and get back to zero then that will re-legitimise lockdown as a strategy for a bit longer. We've got a few "open 'er up and let it rip" friends and I just don't get it. There are so many potential game changers when you are an island. If a reliable saliva-based test appeared that produced results in say 2 hours we could reduce MIQ and use waiting booths at the airport. Even if it was only 99% accurate we could pool groups of 20 into rooms together while waiting for results. So many possibilities if we continue to think critically instead of politically. |
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Tests for disease rely on two numbers:
1. "sensitivity" - the proportion of people with COVID who get a positive test
2. "specificity" - the proportion of people without COVID who get a negative test.
COVID, despite the media attention, is a rare disease compared to the number of people tested. Say we have 10,000 people tested for COVID at the airport. We have 99% sensitivity and 99% specificity. And we know 100 people have COVID (1% prevalence) in this group. Our test would find 99/100 of the positive cases. But it would also find an additional 99 false positives! It also misses one true positive case. Which would be disasterous for the quarantine measures in place in Australia and NZ. In short, even a gold standard rapid test is not enough, although at 99% specificity and sensitivity it would be somewhat useful.
This is a lot less intuitive than it looks. The companies pushing rapid antigen tests at the start of the pandemic would have know better, but they chose to lie to the public about this.
https://en.wikipedia.org/wiki/Sensitivity_and_specificity