A journalist wears a mask when attending a briefing on H7N9 virus prevention and control in Shanghai on Apr. 2, 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]