Accra/Lusaka/Pretoria —Twice a week, a team of scientists from South Africa’s National Institute for Communicable Diseases (NICD) traverses the country’s metropolitan areas, visiting up to 50 wastewater treatment sites to fill bottles with effluent. The bottles are sealed and disinfected, then transported to a network of laboratories across the country where their contents will be tested for the presence of SARS-CoV-2, the virus that causes COVID-19.