IN A STRANGE TWIST of evolution, the influenza virus seems to have endless capability to reinvent itself, infecting waterfowl, swine and humans over and over again with great power and destructive force. A periodic reassortment of its genes gives rise to new variants that have not been seen before. Each time, the new variant poses a potential threat to both man and animal. Another shuffle of the deck has just occurred, leading to a new outbreak of bird flu in China, where people and fowl are often in close contact.

This variant, known as H7N9, has not reached U.S. shores, but it is a reminder of the unpredictable nature of influenza. It might cause a pandemic, or settle into a slow burn for years, or simply die out. At this stage, no one knows. The uncertainty ought to remind us of past lessons about infectious disease and globalization, which remain as urgent as ever.

One of those lessons is the vital role of rapid communication about an emerging outbreak. A decade ago, a virus known as severe acute respiratory syndrome, or SARS, took hold in China. The Communist government, which keeps a tight grip on information, responded poorly to the threat and failed to report early cases as the virus spread. It was a vivid example of the dangers of a closed society. As Mikhail Gorbachev found out after the Chernobyl nuclear accident, there are some events — spreading radiation or a virus — that just can’t be hidden from the rest of the world.

This time, China has reacted differently. The authorities announced the early cases, reported details to the World Health Organization, deposited genetic sequences of the virus in an open database and shared isolates of the live virus with scientists. While China’s rulers still impose a dark curtain of censorship over much other news, the authorities deserve credit for recognizing the global demand for openness about the new bird flu virus. So far, infections have been confirmed in 129 people, of whom 31 have died.

The critical tripwire that could lead to a pandemic would be sustained human-to-human transmission of the virus. Until now, there have been small clusters of people infected but not sustained transmission. Still, China is not out of the woods. Early indications suggest that this variant of influenza can infect birds without them showing obvious signs and symptoms, meaning it could spread in flocks and not be visible, endangering humans who come into contact with the birds. China may need to cull millions of birds, a challenge it has not yet faced.

It is natural for people to grow fatigued about warnings of pandemic. If it hasn’t happened, why worry? Here’s why: Germs do not stop at passport control. What happens in China today could happen here tomorrow. Bird flu is everyone’s problem, and we can only hope that China continues to fight it effectively and with transparency.