I find tracking waste water very interesting and here is Switzerland it has been done for a while now. It may allow to find outbreaks before the population does testing regimes.<p><a href="https://www.swissinfo.ch/eng/-sewage-doesn-t-lie--when-tracking-covid-19/46582322" rel="nofollow">https://www.swissinfo.ch/eng/-sewage-doesn-t-lie--when-track...</a>