How WC health authorities use sewage to identify COVID cases in communities The South African Medical Research Council (SAMRC) last year introduced a sewage-based early warning system for the coronavirus in some parts of the country. A team at the South African Medical Research Council (SAMRC) shows us how the long process of testing sewage samples begins. They aren’t looking for a live coronavirus, but are searching for RNA, a nucleic acid similar to DNA. Picture: Zukile Daniel/Eyewitness News. 26 days ago CAPE TOWN - Health authorities have stressed the importance of rapidly detecting a rise in COVID-19 infections in communities, especially under level 1 of the national lockdown.