HANGZHOU, April 4 (Xinhua) --Another H7N9 bird flu case has been confirmed in east China's Zhejiang Province, the provincial health department said Thursday, bringing the country's total number of cases to 10. The patient is a 64-year-old man from Huzhou City. He became ill on March 29 and was admitted to a hospital in Huzhou on March 31. On Thursday, medical experts confirmed that he was infected with the H7N9 bird flu strain after the provincial center for disease control and prevention said late Wednesday that he tested positive for the virus. An investigation has found that all 55 people who had close contact with the man have not showed any abnormal clinical symptoms, the department said. So far, China has confirmed 10 H7N9 cases -- four in Jiangsu Province, two in Shanghai Municipality, one in Anhui Province and three in Zhejiang. The two patients in Shanghai and one in Zhejiang have died. Health authorities and hospitals in many Chinese provinces have been on high alert for H7N9 cases. In Nanchang, capital of Jiangxi Province, which neighbors Zhejiang, five hospitals have been selected and ordered to be ready to treat H7N9 patients, though no cases have been reported there. China's health authorities have promised transparency  and cooperation to the World Health Organization (WHO) in regards to human infections of the new strain of bird flu. On Wednesday afternoon, the National Health and Family Planning Commission distributed prevention and control plans and technique directives to health institutions nationwide. "So far, the sources of infection have not been clear, but based on past experiences and recent epidemiological   studies, the sources could be poultry or the secretion and excrement from poultry," according to the plan. The Chinese Center for Disease Control and Prevention said Wednesday that no human-to-human transmission of H7N9 has been discovered and no epidemiological connection between these cases has been found. Which of the following statements is true according to the passage?
Four H7N9 cases have been confirmed in Zhejiang including the old man. People who had close contact with the man are infected with bird flu too. So far three people have died of H7N9 bird flu. China kept back the truth of human infections from the WHO.