BEIJING : Amid a flare-up of Covid-19 cases across the country, Chinese citizens may have to undergo an embarrassing anal swab test for virus detection, prompting some of them to vent their ire on social media.Beijing has rolled out the anal swab tests for key groups, focusing on persons returning from abroad and living in high-risk areas, state-run Global Times reported on Thursday.According to health experts, taking an anal swab can increase the accuracy in detection of the virus, as according to studies the virus survives longer in the anus or excrement than in samples taken from the upper body tracts, the report said.An internet user on Xiaohongshu, a social media platform, said that she had a "mental meltdown" when she was informed.