China's lockdown of an entire city to contain a virus outbreak stands in contrast to its handling of the deadly Severe Acute Respiratory Syndrome (Sars) crisis two decades ago, when it was criticised for being secretive and indecisive.

The new virus has killed 17 and infected more than 500 other people, with most cases found in Wuhan, the central city of 11 million people where outward flights and trains were indefinitely suspended on Thursday.

Like Sars, China’s new disease is contagious between humans and is part of the same family of coronaviruses.

But unlike the 2003 Sars epidemic, when China drew international condemnation for covering up cases, Beijing is taking a starkly different approach to contain the new disease, experts say.

“Chinese authorities express the willingness to collaborate more transparently and more quickly than for [the] Sars outbreak,” said Antoine Flahault, deputy director of the Swiss School of Public Health.

“This is [a] tremendously different attitude from 2003, although there are some pending questions regarding the exact number of cases and potential for underreporting.”

The consequences of the information blackout during the Sars outbreak were keenly felt in China.

Nearly 650 people died across the mainland and Hong Kong from the disease.

During the Sars epidemic, the Chinese government took months to report the disease and initially denied World Health Organisation (WHO) experts access to southern Guangdong province, where it originated.

But Beijing – well-aware its response will be compared with the legacy of Sars – seems determined not to repeat the mistakes of 2003 with the new coronavirus.

Even state media has admitted that “government agencies cannot hide information even if they want to” in the age of social media.

“The whole nation has sharpened its vigilance,” said Zhong Nanshan, a renowned scientist at China’s National Health Commission, state television reported on Monday.

“The Sars epidemic of 17 years ago will not be repeated.”

The disease has also spread to other countries, including the US, South Korea, Thailand, and Japan.

The Chinese government has published regular updates of the new virus since announcing its appearance at the end of December, the exact opposite to its response in 2003.

The country saw its first case of Sars in November 2002, but Beijing waited until February to officially acknowledge the disease, which it downplayed then as “effectively controlled”.

Chinese authorities also repeatedly failed to coordinate with the WHO, which urged “full and open” reporting of cases.

In addition to Guangdong province, WHO experts were also blocked from accessing Beijing military hospitals with suspected Sars patients.

By early June 2003, more than 300 people in China had died from the disease, while another 5,329 remained infected.

In contrast, the head of the WHO, Tedros Adhanom Ghebreyes, on Wednesday hailed the “very, very strong measures” taken by China this time around.

He praised its openness about the current outbreak as “commendable”.

Tedros spoke after the global body held a meeting on Wednesday to decide whether to classify the outbreak as a global health emergency. International experts were split and a new meeting will be held on Thursday.

In Washington, a US State Department official said on condition of anonymity that there have been “encouraging signs that the Chinese government has understood the gravity of this problem”.

But the official added: “We’re still concerned as far as transparency in the Chinese government.”

Prioritising social stability over public health may have thwarted an earlier response to the Wuhan virus, said Dali Yang, a political science professor at the University of Chicago.

At the beginning of this month, when Wuhan officials held an annual political meeting, the local government tried to “project this atmosphere of stability and calm in the region”, he said.

The mayor of Wuhan has also faced scrutiny for allowing a massive Lunar New Year banquet – involving 40,000 families – to take place on Saturday.

In an interview with CCTV on Tuesday, he defended the decision by saying it was made before human-to-human transmission was officially confirmed on Monday.

There are also discrepancies between the number of infections reported by China and estimates from overseas researchers.

Scientists at the Imperial College in London published an estimate on Wednesday that 4,000 people have been infected in Wuhan – much higher than the more than 500 cases reported by Chinese officials.