The Chinese city of Wuhan relaunches mass testing against covid19

Authorities in China's Wuhan said Tuesday they would test the city's entire population for Covid-19, as the virus returned to the place where it first emerged and the highly contagious Delta variant drove tightening lockdowns worldwide.

A resurgent virus has returned with a vengeance, buoyed by stalling vaccination rates and deadly new mutations even in places which had long touted their successes in overcoming the worst of the pandemic.

China brought domestic cases down to virtually zero after the coronavirus first emerged in Wuhan, allowing the economy to rebound and life to return largely to normal.

But a fresh outbreak has thrown that record into jeopardy, as the fast-spreading Delta variant reaches dozens of cities after infections among airport cleaners in Nanjing sparked a chain of cases that have been reported across the country.