A worker is carrying out a thorough cleaning and disinfection at a live poultry trade market in Nanjing, Jiangsu Province on Apr. 3, 2013. Authorities in some Chinese regions have ordered health institutions to step up monitoring of H7N9 bird flu as four more cases were reported Tuesday. The order comes after seven people in east China's Jiangsu Province and Shanghai have been confirmed as being infected with the lesser-known H7N9 bird flu. [Chinanews.com]