A new coronavirus that has killed at least 17 people in China and spread to several other countries is already putting global measures designed to fend off epidemics to the test.

The looming question is whether the international community will try to stem its spread by implementing what it learned during the deadly outbreak of severe acute respiratory syndrome, or SARS, between 2002 and 2004, which also began in China. At the time, China denied the existence of the SARS virus, even as it spread across the country and abroad, eventually killing more than 770 people worldwide.

This time, Chinese authorities were initially praised for what some observers called a relatively fast response. China first reported a pattern of unknown pneumonia-like cases in the city of Wuhan in late December. It shared details about the virus — including its genetic sequencing — with other countries and revised its initial assessment that the virus is unlikely to spread between humans. Authorities have offered daily updates and have said the number of infected people in China has passed 470.

J. Stephen Morrison, director of the Global Health Policy Center at the Center for Strategic and International Studies, said it is clear that Chinese President Xi Jinping is trying to avoid a disaster that will implicate Chinese authorities in a coverup reminiscent of the SARS outbreak. Their response this time “has been far superior and fundamentally different” compared with 2002 and 2003, Morrison said.

But some analysts have already raised doubts over whether the Chinese figures are accurate. Imperial College London researchers estimated Wednesday that the number of cases in Wuhan had probably risen to around 4,000 by Saturday — vastly exceeding the number of cases China had confirmed. The researchers did not accuse Chinese authorities of a deliberate coverup, suggesting instead that “further refinements to case definitions and testing and further expansion of surveillance” could lessen the “differences between our estimates and official case numbers.”

Still, these discrepancies reflect lingering skepticism over whether recent efforts to foster global cooperation on health epidemics have been sufficient and whether the world has learned its lessons from SARS.

In the fallout of the outbreak that began in 2002, the World Health Organization criticized a range of countries — including China, the United States and Canada — for not sharing sufficient information. But the lack of cooperation, researchers said, reflected deeper organizational flaws at the WHO as well.

By the time that outbreak hit, the WHO had not significantly changed its regulations for three decades. SARS was a wake-up call, speeding up revisions.

“Over time, the shortcomings of the 1969 version of the [International Health Regulations] became increasingly apparent,” a WHO review committee acknowledged in 2011. Overall, the committee argued, the regulations were ill-equipped for the increasingly globalized world of 2003, when the SARS outbreak reached its peak.

The world has become more interconnected since then, raising concerns that high rates of movement in and out of China could raise the risk of the spread of this coronavirus as hundreds of millions of people prepare to travel for the Lunar New Year.

In 2003, the World Health Assembly also voted to grant the WHO more authority to get involved in individual countries’ responses to health crises. While the effort appeared largely directed against China, it was the United States that unsuccessfully attempted to delay the measures amid concerns that the changes might diminish the role of its Centers for Disease Control and Prevention.

Two years on, in 2005, the International Health Regulations — which outline the organization’s authority and the rules it is bound by — were radically overhauled to reflect the WHO’s expanded role. Whereas the rules previously required the reporting only of cases of yellow fever, the plague and cholera, they were revised to cover “any event that may constitute a public health emergency of international concern,” or PHEIC.

Some experts have raised doubts over the extent to which some of those revisions were implemented. Kelley Lee, author of a book about the WHO, said in an email that many countries still lag behind on their 2005 commitments to expand their capacity to respond to health emergencies.

The WHO has not yet declared this latest outbreak a PHEIC, but Morrison said he expects it will, because it has spread so quickly to other countries, with one case diagnosed in the United States.

Countries do not always welcome such moves, because they “do not want to be seen as losing control,” Morrison said.

In Congo, it took around a year for the WHO to give a deadly, ongoing Ebola outbreak that designation, even after it infected more than 2,500 people and killed nearly 1,700. The delay drew criticism from many public health experts.

Even after the declaration, Robert Steffen, chairman of the WHO emergency committee, said the Congo outbreak “is still a regional emergency and by no way a global threat.”

The emergency declaration came amid concerns Ebola had the potential to spread rapidly into neighboring countries, especially after a patient died in Goma, a city of 2 million on the border with Rwanda.

Still, efforts to control the outbreak, largely confined to Congo’s North Kivu province, have proved difficult. The region has experienced decades of conflict, sowing deep distrust in the government. Armed groups have attacked clinics and killed several medical workers, increasing fears among people who might have already been reluctant to seek treatment.

But officials there also knew that the threat of a major international outbreak was less likely, Morrison said, because they were dealing with communities that are less likely to travel internationally by plane or have foreign visitors.

In Wuhan, a city of 11 million people, the numbers of people traveling in and out was “staggering,” he said. And officials did not suspend travel until Wednesday, weeks after the outbreak was first documented.