This photo taken on April 25, 2020 shows medical workers wearing protective gear looking for close contacts with patients that tested positive on nucleic acid tests for the COVID-19 coronavirus in Suifenhe in China's northeastern Heilongjiang province. - New clusters of coronavirus infections in northeastern China near the Russian border forced officials on April 22 to tighten restrictions on movement as they seek to prevent a second outbreak of the contagion. (Photo by STR / AFP) / China OUT