A worker cleans the chicken coops at a live poultry market in Hong Kong, south China, April 8, 2013. Hong Kong has reinforced efforts in its H7N9 prevention measures, including strengthening inspection on live poultry supply. China reported three more H7N9 infections on Sunday, bringing the total number of the confirmed cases to 21 as the country is gearing up to fight the disease that has left six dead. [Xinhua]