Why the coronavirus outbreak increasingly looks like a pandemic

Health experts say it’s time to prepare for worldwide spread on all continents.

During the last two months, as the Covid-19 coronavirus outbreak has spiraled into a global threat, countries around the world have scrambled to impose travel bans, quarantine millions, and isolate sick people in an attempt to stop the spread of the new virus.

Yet, as of Sunday, there were 78,000 cases of Covid-19 in at least 29 countries, including surging case tolls in Italy, Iran, and South Korea, as well as an ongoing outbreak on a cruise ship off Japan.

The likelihood that we’re hurtling into a pandemic — a new disease that spreads around the world — or that we’re already in one, seems higher than just a week ago.

“Our window of opportunity [for containing the virus] is narrowing so we need to act quickly before it closes completely,” said World Health Organization Director General Tedros Adhanom Ghebreyesus, on Friday.

But other public health experts think the window has already closed. They say worrisome, new developments in this outbreak suggest containing the virus — particularly in low-resource settings — may no longer be possible, if it ever was.

“I don’t think the answer is shutting down the world to stop this virus. It’s already out,” Michael Osterholm, director of the University of Minnesota’s Center for Infectious Diseases Research and Policy, said.

“When several countries have widespread transmission, then spill-over to other countries is inevitable,” said Anthony Fauci, head of the National Institute of Allergy and Infectious Diseases. “One cannot shut out the rest of the world.”

If halting the spread of the virus is increasingly out of reach, public health officials will have to accept that it’s everywhere — and move into a new phase of readying for a pandemic. “We are at a turning point in the Covid-19 epidemic,” said Lawrence Gostin, a global health law professor at Georgetown University. “We must prepare for the foreseeable possibility, even probability, that Covid-19 may soon become a pandemic affecting countries on virtually all continents.”

A look at new outbreaks outside of China, and what they tell us about how this disease is spreading, helps explain why.

Numerous countries (and one cruise ship) have seen rapid spread of the coronavirus

Source: Johns Hopkins University Center for Systems Science and Engineering

As of February 23, there were more than 1,800 cases of Covid-19 outside of China in at least 29 countries. That’s an increase from around 500 cases just over a week ago.

Many of these new cases are occurring in people who never traveled to China, or from an unknown source. The virus has also entered a few relatively contained environments — cruise ships and prisons — and spread like a wildfire, revealing its contagiousness and how difficult it is to stop. Let’s dive into the latest developments:

Philip FongP/AFP via Getty Images

The Diamond Princess Cruise Ship in Japan, which quarantined 3,600 passengers and crew after an 80-year-old man tested positive for the virus, now has 634 cases associated with an ongoing outbreak there. That’s the largest outside of China. Japanese authorities ordered the quarantine in early February in an attempt to try and contain the virus — but the effort dramatically backfired.

“They’ve basically trapped a bunch of people in a large container with [the] virus,” said University of Toronto epidemiology professor David Fisman, over email. Public health experts and researchers now believe the quarantine probably generated more cases — both because the virus appears to be highly contagious and proper quarantine protocols weren’t followed.

By February 18, Japanese officials began letting passengers off the ship who tested negative for the virus — and within days, a case turned up among them, mirroring the situation on another cruise ship in Asia, the Westerdam. After one woman disembarked, she tested positive for the virus in Malaysia, setting off a global search for other passengers who have may been exposed.

South Korean Presidential Blue House via Getty Images

South Korea has now reported the most cases outside of China: 602 as of Sunday — up from only 30 on Monday. Many of them are linked to a secretive religious group, known as the Shincheonji Church of Jesus in the city of Daegu.

The country’s president, Moon Jae-in, has put South Korea on its highest level alert over the outbreak, giving cities the power to impose their own containment measures. “This will be a momentous time when the central government, local governments, health officials and medical personnel and the entire people must wage an all-out, concerted response to the problem,” he said, according to the New York Times.

Iranian Supreme Leader Press Office/ Handout/Anadolu Agency via Getty Images

As of Sunday, Iran reported 28 cases, including 5 deaths — days after authorities there said they had no Covid-19 within their borders. Cases with links to Iran have already turned up in Canada and Lebanon.

Very quickly, the country’s narrative about the virus has changed. Schools and universities across the country are being shuttered as a “preventive measure,” according to Al Jazeera, along with some cinemas and restaurants. But this outbreak might be much larger than it looks now, Sylvie Briand, the director of infectious hazards management at the WHO, said in a media briefing Friday. “We are wondering about the potential for more cases to be exported in the coming days. We want all countries to be aware of this and to put in place detailed measures to pick up these cases as early as possible.”

Miguel Medina/AFP via Getty Images

Italy is now home to the biggest Covid-19 outbreak outside of Asia: some 132 people have confirmed infections including at least two deaths. The worrisome rise in cases in the country’s north has prompted authorities to impose severe measures to try and stop the virus. Sporting, religious, and cultural events are cancelled, along with university classes. Authorities are also fining anyone who tries to enter or leave areas where the outbreak is occurring, including 11 towns in the Lombardy region.

Why this looks like the beginning of a pandemic

The developments outside of China, along with the latest science on Covid-19, suggest we may soon see a rapid rise in infections — in China and around the world.

1) The virus is very contagious and some people seem to be able to infect others before they know they’re sick: Researchers currently believe one infected person generally infects two to more than three others, which would make the new coronavirus more contagious than other coronaviruses, like SARS and MERS.

“For a virus pretty closely related to SARS, it shows very effective person-to-person transmission, something nobody really expected,” Stephen Morse, a professor of epidemiology at Columbia University Mailman School of Public Health, told Vox. Look at the cruise ship in Japan, the thousands of healthcare workers in China who are infected, and the situation in China’s prisons for more evidence of Covid-19’s potential for rapid spread.

At the same time, the latest science suggests some people can transmit the virus very early on in their illness or even before they are showing symptoms — which is again different from SARS and MERS, and suggests contagion more like the flu virus than SARS. SARS was eventually contained because, when people began to show symptoms, they were isolated — at a time when they only just becoming contagious — and their contacts could be traced and isolated too, explained Minnesota’s Osterholm. But, “Trying to stop influenza-like transmission is like trying to stop the wind. It’s virtually impossible,” he told Vox.

For these reasons, Osterholm said the fact that extraordinary measures to contain this virus haven’t worked doesn’t mean containment failed. “Containment never had a chance because of the influenza-virus like transmission.”

2) Countries are still mostly looking for the disease in people who’ve traveled from China: The main method of screening in many countries is still testing passengers coming from China, or from Hubei province only. But as we’ve seen, spread is happening beyond those people. And other cases may be undetected.

“What happened in the UK, where a cluster of infections was started by someone who was infected outside of China, could happen in the US,” Jennifer Nuzzo, an infectious disease expert and senior scholar at the Johns Hopkins Center for Health Security, told Vox. “I’m not confident we’d catch it before it spread on, since we’re using severity of symptoms and history of travel to China as criteria for testing people for this virus.”

“There’s a high probability that we’ll see community spread in the US,” she added.

Though the US Centers for Disease Control and Prevention maintains that the risk of spread in the US is low, it’s beginning to change its screening strategy to look for people with the virus who aren’t returning travelers from China. The CDC will use the national flu surveillance tracking infrastructure to test patients who have flu symptoms for Covid-19 in five cities across the US.

3) With flu season ongoing, it can take time to identify cases and outbreaks: “The challenge with this illness is that the clinical symptoms resemble other viral illnesses, like flu,” Tom Inglesby, director of the Center for Health Security of the Johns Hopkins Bloomberg School of Public Health, told Vox. So people with the flu, and doctors examining them, may not even be thinking of Covid-19 yet, especially in people who haven’t traveled to China.

4) China may also see another surge in cases soon as travel restrictions are gradually lifted: The country has taken extraordinarily draconian measures to stop this virus — quarantining millions, and shutting down transit and travel. But the business community is growing increasingly frustrated with the restrictions, and is pressuring government officials to lift some of them.

“[It’s] the most intense human social distancing effort in modern public health,” Osterholm said. “What happens when all these people start to go back to work, and public transport is back, and crowding occurs? This is at best a temporary respite in the numbers in China.”

5) Many countries are only now getting testing up and running: Until last week, only two countries in Africa — Senegal and South Africa — had the lab capacity to screen for this virus. While other countries are now scaling up, this outbreak has been going on since late last year, and it’s possible cases have gone uncounted.

So far, only one case has been detected in Africa — in Egypt — yet Africa is thought to be at particular risk given its economic ties to China, with more than a million Chinese workers.

“If the disease spreads to fragile states it would be even harder to contain. Many states are undergoing political violence or are poorly governed, such as Syria, the Democratic Republic of the Congo, Yemen, and Afghanistan,” said Gostin. “Others have weak health systems, for example in sub-Saharan Africa.”

6) Some people may have abdominal pain before respiratory symptoms — and that’s not something health officials are screening for: This coronavirus is still very new, and we don’t know the entire spectrum of illness yet, but we’re learning the disease may sometimes surface in surprising ways. Though it’s a respiratory infection, a recent JAMA article found some have abdominal symptoms such as discomfort first. This means “we may not be detecting cases that do not present in the classic way with fever and respiratory symptoms,” said William Schaffner, an infectious disease expert at Vanderbilt University.

Putting all this aside, models have repeatedly suggested there are thousands more cases than have been detected. (One of the latest, from Imperial College London, estimated that about “two thirds of COVID-19 cases exported from mainland China have remained undetected worldwide, potentially resulting in multiple chains of as yet undetected human-to-human transmission outside mainland China.”)

We need to prepare for a pandemic

Keep in mind: A disease can spread widely, and become a pandemic, without being particularly severe. And no one knows yet what the death rate of a Covid-19 pandemic would be — mostly because we don’t yet know precisely how lethal this disease is.

On February 16, China’s CDC published a report of the first 72,314 patients with confirmed or suspected Covid-19 in mainland China. It’s the largest such analysis to date. And it found an overall case fatality rate of 2.3 — suggesting Covid-19 is less deadly than SARS, which killed around 10 percent of those infected. The death toll was also much higher among the elderly.

As more and more mild or asymptomatic cases are found, the death rate is likely to drop. Still, Osterholm warned, even a 1 or 2 percent case fatality rate could equate to a lot of deaths if Covid-19 continues to spread around the world. “A two percent case fatality rate is 20 times higher than a bad flu year,” he said. (Seasonal flu has about a 0.1 percent case fatality rate.) “So now, you can infect many more people than the flu and add a case fatality that is as much as 20 times higher.”

What’s more, a less severe pandemic still has the potential to overwhelm a country’s health system. The current data out of China suggest as many as five to ten percent of patients need care in the ICU, Osterholm said. Many countries may not have enough beds or equipment to care for them, not to mention it could cost billions.

“We don’t have enough data to know what the burden will be in the US,” Inglesby added, “but there does seem to be enough information that hospitals and public health agencies should be planning for a potential rise in very sick people that will need critical care in the months ahead.”

Public health experts said countries need to move from trying to contain the virus to mitigating its harm — reducing the spread, and caring for the very sick. “It is beyond time,” said Nuzzo. This means hospitals need to be ready with Covid-19 protocols, healthcare workers need to be protected with access to protective equipment such as face masks, and countries need plans for maintaining supply chains and carrying on with travel and trade.

Recent outbreaks in Germany, France and the UK suggest high-income countries with strong public health systems may be able to control the virus’ spread, at least for now. (In these places, after Covid-19 cases were detected, the counts didn’t rise appreciably.) But as the virus moves around the world, and the case toll mounts in more and more countries, sometimes silently, even high-income countries will struggle, Osterholm said. “I think we have to expect there are going to be many locations around the world that will experience what China is experiencing.”