How the new coronavirus outbreak gets better — or much worse

Four factors that could cause it could devolve into a dangerous pandemic, and four ways it could steadily improve.

We’re at a pivotal moment in the outbreak of the new coronavirus in China. Depending on whom you ask, we’re either already in a pandemic, meaning there are ongoing epidemics of the virus on two or more continents; we’re hurtling toward one; or we’re on the path to averting a spiraling crisis.

As of February 5, more than 24,500 people have been infected with 2019-nCoV, as the respiratory virus is known, and 494 people have died. There are also 185 cases in 25 countries besides China, including one death in the Philippines. This toll represents a tragic and stunning increase from a month ago, when it looked like there were no more than 50 patients with the virus in Wuhan, the mainland Chinese city where the virus is thought to have originated.

There’s still so much we don’t know about 2019-nCoV, including how exactly it’s transmitted, where it’s spreading, and how deadly it is. And that uncertainty is important because viruses have funny ways of surprising us: H1N1 “swine flu,” which was a pandemic, turned out to be much less deadly than feared. (A disease can be pandemic and not particularly severe.) Ebola, meanwhile, was known to science for decades and then behaved in ways that caught infectious disease experts off guard during the 2014-2016 epidemic in West Africa.

Given the unknowns about 2019-nCoV, in the coming days and weeks, we’re in for some twists and turns. For now, many experts believe this outbreak could get a lot worse: burdening the Chinese health system, spreading in poorer countries with weaker health systems, and sickening and killing thousands more people along the way. Alternatively, it could get much better, with new cases and deaths steadily dropping. Here are the key factors that will determine which way it goes.

4 ways this outbreak could take a turn for the worse

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1) China can’t contain the new coronavirus

China first reported this outbreak to the World Health Organization on December 31, 2019. Since then, scientific reports have emerged suggesting the disease likely began spreading several months earlier, sometime last fall. Either way, this means that in just the span of a few months, the virus has infected at least 24,500 people in China and spread around the world. That’s an unusually rapid rise for a brand new virus. It’s also stunning when you consider the draconian measures China has taken to control the virus, including an unprecedented quarantine of more than 50 million people.

And there is the very real possibility that the true case toll is even higher — because China may not have the capacity to find and detect new cases, people with mild illnesses may not be going to the hospital and therefore won’t be counted, and other countries may not be looking for cases (more on that in a second).

Plus, there have also been questions about China’s willingness to share data — and whether officials there are honestly reporting the extent of the problem. According to a new model, published in The Lancet by academics at the University of Hong Kong, 75,000 people may have been infected in Wuhan alone as of January 25.

So what does all this mean?

“The way it’s looking, if it continues to accelerate, we very well may have a pandemic,” said Tony Fauci, the head of the National Institute of Allergy and Infectious Diseases. There will be more sicknesses and deaths not only in China, but also in other countries around the world, as cases grow from one-off travelers or small clusters to full-blown outbreaks.

It also suggests, he added, that “you don’t try to control [the virus] because it’s already everywhere.” So public health officials would move from attempting containment of the virus to mitigating its impact — setting up hospitals to isolate and care for patients, making recommendations for “social distancing” (like canceling public events), and coming up with triaging protocols for the many people who might need hospital care.

2) The new coronavirus spreads in countries with weak health systems

Of particular concern is the potential that the virus could start spreading in countries with weaker health systems, where officials would have an even harder time limiting the spread than China has. Or maybe it already is. “For all we know, this is already endemic in multiple countries,” said Tom Frieden, the former director of the Centers for Disease Control and Prevention. “If this spreads widely like the common cold, not even China can control the common cold.”

China is an upper-middle-income country with a world-class network of scientists, a reasonable number of health care workers per person, and a robust disease detection network, meant to pick up new outbreaks as they happen.

But many countries around the world don’t have these advantages. That’s part of the reason, for example, it took months to identify the 2014-2016 Ebola outbreak in West Africa, which eventually sickened more than 28,000 people and killed 11,000.

Saad Omer, director of the Yale Institute for Global Health, says outbreaks in these low-resource settings pose a particular concern — and not only because they’re more likely to be missed.

“We know a disease’s [lethality] differs by population,” Omer said. “It’s better when a health care system is more robust and worse when the health system is an issue.” So even if this new coronavirus doesn’t look very deadly in China right now, the same may not be true for countries in Africa. And Africa may be at particular risk given its links with China, with more than a million Chinese workers there.

3) The virus is actually deadlier than it seems right now

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One hallmark of the Spanish flu pandemic of 1918 was that it didn’t just prey on the very young and old; it killed seemingly healthy people in the prime of their lives. And even though the case fatality rate — or number of deaths per person infected — was just 2.5 percent, because the world’s population was naive to the virus, and the virus could spread easily and kill broad swaths of the population, that 2.5 percent meant 20 million to 50 million people died by the time the pandemic was over.

With the new coronavirus, “the deaths still appear to be in people who are at risk of dying of other respiratory diseases — elderly and people with underlying health conditions,” said Jennifer Nuzzo, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security. So unlike Spanish flu, the novel virus doesn’t yet appear to be killing otherwise healthy, young people.

But 2019-nCoV’s case fatality rate is also hovering around 2 percent at the moment, Nuzzo added in the same breath. (It may be slightly higher in Hubei, China’s hardest-hit province and home to Wuhan.)

If this holds, “that would be bad because of the numbers it’s infecting.” In the worst-case scenario of a global pandemic, a 2 percent case fatality could “translate to a lot of illnesses and deaths.”

4) Travel bans isolate countries, spread xenophobia — and exacerbate outbreaks

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In the past week, Russia, Singapore, and Australia have sealed their borders to China while the US government dramatically escalated its response — declaring a public health emergency, issuing its highest-level travel advisory (which essentially reads “don’t go to China”), and temporarily barring foreign nationals who have recently been to China from coming in.

The fallout from these moves is affecting much more than public health; it’s threatening everything from the global economy to China’s manufacturing industry, and even business at Chinese restaurants far from the hot zone.

Reports are already piling up to suggest this virus — and the global reaction to it — has exacerbated anti-Chinese sentiment, with Chinese individuals facing new kinds of discrimination. And that’s on top of the reports of food and medical supply shortages in China.

Beyond the psychological and economic toll, isolating China could have far-reaching effects on the outbreak response — namely, spreading fear and driving cases underground.

“[It] sends a signal to other countries who may worry the US [or other countries] will ban travel and make it harder for them in other ways,” said Nuzzo. And that isn’t exactly an enticement for honest reporting of outbreaks beyond China. In fact, other countries may have an incentive to hide cases.

“Right now we’re focused on the disease coming from China to the US,” said former “Ebola czar” Ron Klain, “but soon it could come from other countries to the US.” If countries aren’t reporting what’s happening within their borders, stemming the spread of this disease will be even harder.

4 things that could unfold that would prevent a pandemic

1) China contains the virus

The best salve for the current situation would be China containing this virus so that it stops spreading internally and around the world.

In an interview with Stat, the head of WHO’s Emergencies Program told reporter Helen Branswell that he still believes containment is possible.

“That is not to say that the disease won’t get ahead of the Chinese authorities completely or get ahead of the other countries that are containing it,” the WHO’s Mike Ryan said. “But there’s enough evidence to suggest that this virus can still be contained.”

Ryan pointed to evidence suggesting the virus isn’t as transmissible as it might seem right now — including the low rate of infections within households when one person is infected, and the seemingly low number of health care worker infections.

2) Local clusters of the disease in other countries don’t grow

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Relatedly, no country where the virus is known to have spread has declared a local outbreak yet. (That’s why the US government is firm that the risk to the general American public of this coronavirus remains low, even though there are now nearly a dozen cases in the US.)

“Right now, it’s clearly an epidemic in China and whether it becomes a pandemic is going to depend on whether there’s sustained transmission in multiple locations around the globe,” said Fauci. “And right now, the majority of non-China infections are travel-related.” If that trend continues, and the virus isn’t yet moving into communities outside China, it’ll minimize the risk of a pandemic.

3) The virus can’t spread in poorer countries with hotter climates

Among the many mysteries of the new coronavirus: We don’t know how it behaves in places with hot climates, such as countries in Southern Africa.

“Coronaviruses are winter viruses,” Fauci said. “When the weather is warm and moist, these viruses don’t spread as well as when the weather is cold and dry.”

While it remains a concern that developing countries in the global south don’t have the health systems to detect the virus and do contact tracing, “The somewhat encouraging news is that the weather in some of those countries is warm and moist … [which] favors against the spread of the coronavirus since it’s fundamentally a winter disease,” Fauci said.

4) We learn the virus is not as deadly as it seems

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With SARS in 2003, China delayed reporting the outbreak for months. Then it took several more months to identify the virus causing the disease and develop diagnostics to find infections.

By contrast, the new coronavirus was sequenced within days of its discovery and immediately, countries around the world were able to diagnose cases.

Nuzzo wondered if this immediate diagnostic capability has meant we’re finding more cases faster — as well as more mild cases, inflating the numbers and making the outbreak look worse than SARS did initially.

At the same time, we might learn that the disease, while severe enough to have taken the lives of nearly 500 people, is not as deadly as it seems right now.

If more cases are discovered, or even more asymptomatic cases, the case fatality rate will go down. “What I have long suspected is that the 2 percent [case fatality rate] may not be right,” Nuzzo said. “We could be 10,000-fold off in our case numbers.”

In the best-case scenario, this outbreak might look more like H1N1 swine flu than SARS or Spanish flu. When H1N1 was first recognized in 2009 and spread around the world, there were major concerns about its deadliness. US schools closed, people from North America were quarantined when they arrived in other countries, flights were canceled. Not only did those measures fail to contain the virus, Nuzzo said, it turned out H1N1 wasn’t all that deadly.

“Now we’re still living with that virus — it’s one that circulates with every flu season,” Nuzzo explained.

“I am increasingly in belief that we’re in a pandemic,” she added. “When you deal with 25 countries that are reporting cases, case counts that continue to grow despite very aggressive actions being taken — that signals we’re in a pandemic.” But whether this one will look like SARS, H1N1, or Spanish flu is still very much up for investigation and debate.