The decline poses economic risks, too, as China is a major source of tourism to countries like the United States.

It is, in part, a response to fears that the virus could become a pandemic. In Europe, 47 people in nine countries have been infected so far.

The slowdown in air travel has started to spread to popular destinations for Chinese travelers, like Japan and South Korea.

Thousands of planes criss-cross China every day, but that number has fallen sharply as flights are canceled to help combat the coronavirus.

The disappearance of tens of thousands of flights from China’s skies in recent weeks points to how the coronavirus has hobbled a nation.

The flight suspensions started to mount late last month as countries and airlines sharply limited service in response to the accelerating spread of the virus, which as of Friday has infected at least 76,000 people and killed more than 2,200, most of them in China.

Within just three weeks — from Jan. 23 to Feb. 13 — the number of daily departures and arrivals for domestic and international flights dropped to just 2,004, from 15,072, according to Flightradar24, an industry data firm. Over 13,000 flights a day, lost to a crisis.

China’s daily domestic and international flights International flights Jan. 1 Feb. 13 0 1,000 2,000 3,000 4,000 Jan. 23 Travel bans start Domestic flights Jan. 1 Feb. 13 0 3,000 6,000 9,000 12,000 Source: Flightradar24

Restrictive measures adopted by China helped to delay the spread of the virus to other countries by two to three weeks, the World Health Organization said this week. Officials in China closed off Wuhan, the epicenter of the outbreak, on Jan. 23, and began canceling train, bus and airline travel; closing schools and factories; and pressuring residents to stay home around the country.

But China’s increasing isolation from the world could have lasting economic consequences.

When tourists stop showing up to the temples in Kyoto or the malls in Hong Kong or the beaches in Thailand, their absence is felt. Chinese travelers account for about a fifth of all tourism spending, more than any other country, according to the U.N.’s World Tourism Organization. In 2018, Chinese residents spent $277 billion abroad, according to the U.N., or nearly twice as much as residents of the United States.

Daily flights to the top four destinations for Chinese tourists Japan Jan. 1 Feb. 13 0 150 300 Jan. 23 Travel bans start Hong Kong Jan. 1 Feb. 13 0 150 300 Thailand Jan. 1 Feb. 13 0 150 300 South Korea Jan. 1 Feb. 13 0 150 300 Source: Flightradar24

It’s still too early to tell what the overall impact will be, but Wall Street firms, analysts and economists have been trying to calculate the costs.

As China struggles to reopen for business, a range of companies have warned that the outbreak may weigh on their financial performance. Japan, whose economy had already been teetering, is facing a possible recession. Oxford Economics said in a new report that, in a worst-case scenario, the outbreak could cut $1.1 trillion in global output.

If the coronavirus crisis is anything like the SARS outbreak in the early 2000s, it could eliminate $29 billion in global airline revenue this year, resulting in a small industry contraction, the International Air Transport Association said on Thursday. The vast majority of the losses would be concentrated among airlines in the Asia-Pacific region, it said.

The SARS outbreak wiped out about $6 billion in annual revenue for airlines in that part of the world and it took nine months for international passenger traffic to recover, the association said last month. But the coronavirus has so far proved more lethal, more widespread and more damaging to flight traffic in China, which today plays a far bigger role in global travel than it did two decades ago.