A news blackout has followed a suspected second human bird flu case in Guangzhou, the South China Morning Post reported. A source at Guangzhou No. 1 People's Hospital said a 41-year-old woman was admitted with an unexplained case of pneumonia on March 25, but two days later experts declared she had the H5N1 virus. The details have not yet been reported by state media but the World Health Organization was informed of the case by the Ministry of Health. A WHO spokesperson told the newspaper the woman that sold vegetables in a market had not been confirmed as being infected with bird flu.