But the balanced budgets have deteriorated into large budget deficits. When the pandemic hit, many big emerging economies like those of South Africa, Nigeria and Argentina faced a large “twin deficit” in both the government budget and the current account — a measure of how much nations need to borrow abroad to finance their spending habits. Now spooked investors are fleeing to the relative safety of the U.S. dollar, weakening the currencies of emerging economies — and further undermining their ability to pay their bills.

The result is an unprecedented rush for bailouts: The pandemic crisis has put the I.M.F. back in business. In recent years, the I.M.F. typically fielded 10 to 15 requests for assistance. Since the outbreak began, it has gotten requests from nearly 80 countries for emergency financial help, and the concern now is whether the fund’s $1 trillion dollar war chest is enough to cope with this crisis. Countries from Ecuador to Zambia are already asking creditors for some form of debt forgiveness.

Global trade has also played a role: As it slowed after 2008, many large emerging economies like those of India, Indonesia and Brazil were partly shielded by resilient demand from domestic consumers. With the pandemic, international trade has slowed even further — and it has shut down domestic commerce as well.

More than 15 million Americans have filed for unemployment benefits, but in poor countries some two billion people face joblessness without benefits. Unemployment insurance in developed countries typically covers six out of 10 workers who lose formal jobs, compared with just one out of 10 in developing countries — where most people do not hold formal jobs.

As a result, many officials in the emerging world say they can’t simply copy the measures adopted in wealthy countries. Imran Khan, the prime minister of Pakistan, recently tweeted that South Asia is “faced with the stark choice” between “a lockdown” to control the virus and “ensuring that people don’t die of hunger and our economy doesn’t collapse.”

What comes next is largely up to the virus. While some commentators are already drawing comparisons to the Great Depression, consensus forecasts call for global growth to contract by 3 percent this year and recover sharply next year — which would fall far short of the 6 percent contraction between 1929 and 1932. Government stimulus programs were first hatched in response to the Depression, too late to prevent it, but now the world is rolling out more than $10 trillion in stimulus — more than twice the amount spent between 2008 and 2009 to combat the global financial crisis.

Some real-time coronavirus trackers are showing that the growth rate of the number of new cases started to fall last week both worldwide and in critical hot spots, including Spain, Italy and Germany. Now many emerging-world leaders are hoping that the contagion will be slowed at their border by two factors: warm weather and youth.