Countries including the United States and Australia have moved to set up wastewater testing on flights and in airports amid a surge of cases in China. The European Union also recommends a similar measure and has drawn up guidelines for member states.
One expert said the measure was useful when countries either will not, or lack the capacity to provide information on the circulating variants causing surges in COVID-19 cases in their territories. It is also becoming more important as routine testing has waned – the World Health Organization says testing for COVID-19 has declined by 90% in recent months.