A woman leaves the Wuhan Medical Treatment Centre in Central China's Hubei Province. Photo: AFP

Wuhan has reported four more viral pneumonia cases on Saturday amid the outbreak in the central Chinese city, killing two, prompting public concerns of risks of human-to-human transmission across the country. 

The four patients were identified with the pneumonia on Thursday and were in stable condition, the Wuhan Municipal Health Commission said on Saturday. So far, a total of 45 people have contracted the illness, and five were in critical condition. Other patients were in stable condition and under isolated treatment. 

The authority has put under medical observation 17 people who closely contacted the first pneumonia patient of Thailand, and has been tracking down people who closely contacted the second confirmed pneumonia patient in Thailand. Four people who closely contacted the first confirmed pneumonia patient in Japan are also under medical observation, the Wuhan health commission said. 

New cases diagnosed in Wuhan have sparked concerns from some Chinese netizens who posted on Weibo asking whether the outbreak could spread to other provinces. Some feared it may be another type of severe acute respiratory syndrome (SARS) that caused wide public panic and forced authorities to address public concerns. 

The Chinese Center for Disease Control and Prevention refuted five rumors of the pneumonia on Saturday, including SARS suspicions, and said the new coronavirus found in pneumonia is not SARS and the genetic sequences of SARS and the viral pneumonia have a big difference. 

Liu Youning, a professor of epidemiology and respiratory medicine at the Chinese PLA General Hospital, told the Global Times that more cases found proved signs of human-to-human transmission of the pneumonia, but it appeared to be far less infectious than SARS. 

As both Wuhan and the national health authority have regularly reported the pneumonia cases in detail, it's very unlikely that government has been covering up details of the spread of the disease like what then government did during the outbreak of SARS in 2003 that saw officials sacked, experts said. 

The Chinese Center for Disease Control and Prevention said China established a public incident monitoring system after the outbreak of SARS in 2003, which requires hospitals nationwide to immediately report cases of infectious diseases to the national health information center. All centers for disease control and prevention on different levels could access a daily report on various cases of diseases.