A health worker collects pigeons from a trap at People's Square in Shanghai, China, earlier this month. So far, workers have tested more than 48,000 animals for the H7N9 flu virus.
A vendor weighs a live chicken at the Kowloon City Market in Hong Kong Friday. Health authorities there have stepped up the testing of live poultry from China to include a rapid test for the H7N9 bird virus.
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