Covid-19, as the country shifts focus to contaminated imports after a number of outbreaks linked to frozen food.Workers in hazmat suits were painstakingly screening food shipments across a country which has largely brought domestic infections under control but now blames a resurgence of local infections on imports.Mass-testing campaigns have been rolled out after reports of coronavirus traces on imported food and packaging, with state TV showing workers hosing down food transport trucks with disinfectant and inspecting packages of frozen salmon.In Wuhan, where Covid-19 first emerged late last year, authorities said Friday they had detected traces of the virus on frozen beef from Brazil.Four more cities reported last week that samples from.