Textised! : Jonathan Flint - Testing Woes - LRB 6 May 2021

Perhaps the real problem is hubris. There have been so many things we thought we knew but didn’t. How many people reassured us Covid-19 would be just like flu? Or insisted that the only viable tests were naso-pharyngeal swabs, preferably administered by a trained clinician? Is that really the only way? After all, if Covid-19 is only detectable by sticking a piece of plastic practically into your brain, how can it be so infectious? We still don’t understand the dynamics of virus transmission. We still don’t know why around 80 per cent of transmissions are caused by just 10 per cent of cases, or why 2 per cent of individuals carry 90 per cent of the virus. If you live with someone diagnosed with Covid-19, the chances are that you won’t be infected (60 to 90 per cent of cohabitees don’t contract the virus). Yet in the right setting, a crowded bar for example, one person can infect scores of others. What makes a superspreader? How do we detect them? And what can we learn from the relatively low death rates in African countries, despite their meagre testing and limited access to hospitals? That we are still scrambling to answer these questions is deeply worrying, not just because it shows we aren’t ready for the next pandemic. The virus has revealed the depth of our ignorance when it comes to the biology of genomes.