Every so often, our vague awareness of our vulnerability as a species crystallises around a specific threat. At first, we note with unconcern a handful of cases of a new illness, somewhere far away. Soon it begins to spread. The deaths mount. We start to wonder whether we are being complacent rather than sensible, and whether we are living through the early montage in a disaster movie, in which families bicker over breakfast as news reports on the killer virus play unnoticed in the background. Could this be a new pandemic which will sweep the globe killing tens of millions, as Spanish flu once did?

The story of the new coronavirus, first reported in Wuhan, China, last month, now seems to be reaching the point where public indifference tips into worry and even fear. It causes pneumonia; Beijing says six people have died and 300 have been infected as it has spread. On Monday, officials confirmed that there was human-to-human transmission. Sales of face masks have soared. Cases have been reported in Thailand, Japan, the Philippines and elsewhere, though all confirmed incidents involve patients who had been in China. On Wednesday, the World Health Organization will hold an emergency meeting.

Two other factors fuel the anxieties. The first is that the lunar new year is fast approaching; hundreds of millions of people in China will travel home to celebrate with their families this weekend. The second is China’s handling of the major outbreak of severe acute respiratory syndrome (Sars) in 2003. Officials covered up the problem for months; it took a courageous doctor to expose its scale. Medical experts believe that some of the 800 deaths worldwide might have been averted had China provided more timely information.

China still tightly controls news and social media, suppressing information it considers damaging. Imperial College London researchers estimate that a far higher number of people than reported – around 1,700 – may be affected. Some hospitals may not be testing patients, though it may also be that some patients are not seeking medical treatment. Yet Beijing has responded far more swiftly and strongly than in 2003, and offered much more information. President Xi Jinping has stressed the need for the outbreak to be dealt with and the Chinese political body responsible for law and order has warned officials that those who hide or delay reporting cases “will be nailed on the pillar of shame for eternity”.

Too little information is available to draw firm conclusions about this virus, and its dangers should not be discounted. Its cost has already been felt by the young, the elderly and those with existing medical issues, and there is concern that it could mutate into something worse. But so far, it has not been shown to be as transmissible as Sars, nor to have as high a death rate as Middle East respiratory syndrome, and health experts say China and south-east Asia have much stronger surveillance and reporting procedures following Sars and other epidemics. Meanwhile, the Ebola outbreak in the Democratic Republic of Congo, far less equipped to handle it, remains a serious public health concern, yet garners little attention.

Sounding the alarm unnecessarily has dangers of its own. People may fail to pay heed next time, or may overreact this time: tight movement restrictions can be the very thing to make people feel they should flee. Equally, muting discussions can backfire, especially in a world where information, or unfounded rumours, can be shared so quickly. It is essential that Chinese authorities at all levels are open about this outbreak, as well as assiduous in tackling it.

The rest of us should watch closely too. New outbreaks are worrying, but give us opportunities to improve our preparation for the next threat, be that through increased spending on research, or an understanding that communication is as essential to disease control as handwashing and vaccines.