Staff members of Rospotrebnadzor, Russia's consumer rights and human well-being watchdog, spray disinfectant on hands of passengers upon their arrival at the airport of Kazan, Russia, April 21, 2020. (Sputnik via Xinhua)

Staff members of Rospotrebnadzor, Russia's consumer rights and human well-being watchdog, spray disinfectant on hands of passengers upon their arrival at the airport of Kazan, Russia, April 21, 2020. (Sputnik via Xinhua)

Staff members of Rospotrebnadzor, Russia's consumer rights and human well-being watchdog, spray disinfectant on hands of passengers upon their arrival at the airport of Kazan, Russia, April 21, 2020. (Sputnik via Xinhua)

Staff members of Rospotrebnadzor, Russia's consumer rights and human well-being watchdog, disinfect passengers' luggages at the airport of Kazan, Russia, April 21, 2020. (Sputnik via Xinhua)