NEW : China becomes third city to suspend live poultry trading . Four human cases of Hangzhou have been reported in eastern Hangzhou . No cases of human-to-human transmission have been confirmed . `` We do n't know yet where the humans got their virus from , '' said Dr. Joseph Bresee , who heads the epidemiology and prevention branch of the U.S. Centers for Disease Control and Prevention 's influenza division . Poultry markets in Nanjing and Hangzhou were closed .
NEW : China becomes third city to suspend live poultry trading . Four human cases of Hangzhou have been reported in eastern Hangzhou . No cases of human-to-human transmission have been confirmed . Poultry markets in Nanjing and Hangzhou were closed .