Artist's rendering of a man wearing a surgeon's mask.

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Health officials around the world continue to battle an outbreak of respiratory disease, first detected in the central Chinese city of Wuhan in December. The causative agent was traced to a novel coronavirus, dubbed SARS-CoV-2, in January and has now caused more than 76,000 infections and claimed over 2,200 lives.

The spate of illness was first reported to the World Health Organization on New Year’s Eve and in the following weeks was linked to a family of viruses known as coronaviruses, the same family responsible for the diseases SARS and MERS, as well as some cases of the common cold. A special WHO committee declared a public health emergency on Jan. 30. On Feb. 11, WHO and other organizations agreed to name the new illness COVID-19 (for “coronavirus disease 2019“).

Two Japanese passengers aboard the quarantined Diamond Princess cruise ship, an 87-year-old man and an 84-year-old woman, have died, Japanese network NHK reported Thursday. The pair had underlying health conditions. The deaths are the first for the cruise ship, which was docked in Yokohama for a two-week quarantine period following a cluster of confirmed infections on board and come after an infectious disease expert, Kentaro Iwata, spent time aboard the ship and described the situation as “chaotic.”

China has started clinical trials of two drugs to combat the coronavirus, officials from the WHO announced Thursday. Remdesivir, originally designed to combat the Ebola virus, showed promise in one American patient but hasn’t yet been licensed for use. On Wednesday, a new study in the journal Science showed researchers were able to create a 3D map of a coronavirus protein, paving the way for vaccines to be designed against the virus.

Cancellations have come thick and fast in the video game industry, which has seen Sony Interactive Entertainment pull out of one of the biggest video games conventions in the US, PAX East. The company was scheduled to show off one of its most highly-anticipated titles, The Last of Us Part II, but pulled the pin on attendance citing coronavirus concerns. On Feb. 20, Sony and Facebook Gaming announced they wouldn’t be attending this year’s Game Developers Conference, scheduled to begin March 16 in San Francisco. 

The situation continues to evolve as more information becomes available. We’ve collated everything we know about the novel virus, what’s next for researchers and some of the steps you can take to reduce your risk.

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What is a coronavirus?

Coronaviruses belong to a family known as Coronaviridae, and under an electron microscope they look like spiked rings. They’re named for these spikes, which form a halo or “crown” (corona is Latin for crown) around their viral envelope. 

Coronaviruses contain a single strand of RNA (as opposed to DNA, which is double-stranded) within the envelope and, as a virus, can’t reproduce without getting inside living cells and hijacking their machinery. The spikes on the viral envelope help coronaviruses bind to cells, which gives them a way in, like blasting a door open with C4. Once inside, they turn the cell into a virus factory — the RNA and some enzymes use the cell’s molecular machinery to produce more viruses, which are then shipped out of the cell to infect other cells. Thus, the cycle starts anew.

Typically, these types of viruses are found in animals ranging from livestock and household pets to wildlife such as bats. Some are responsible for disease, like the common cold. When they make the jump to humans, they can cause fever, respiratory illness and inflammation in the lungs. In immunocompromised individuals, such as the elderly or those with HIV-AIDS, such viruses can cause severe respiratory illness, resulting in pneumonia and even death.

Extremely pathogenic coronaviruses were behind the diseases SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome) in the last two decades. These viruses were easily transmitted from human to human but were suspected to have passed through different animal intermediaries: SARS was traced to civet cats and MERS to dromedary camels. SARS, which showed up in the early 2000s, infected more than 8,000 people and resulted in nearly 800 deaths. MERS, which appeared in the early 2010s, infected almost 2,500 people and led to more than 850 deaths.

On Feb. 11, the WHO named the new disease COVID-19. “Having a name matters to prevent the use of other names that can be inaccurate or stigmatizing,” Tedros Adhanom Ghebreyesus, director-general of the WHO, said during a briefing. “It also gives us a standard format to use for any future coronavirus outbreaks.”

The Coronavirus Study Group, part of the International Committee on Taxonomy of Viruses, was responsible for naming the novel coronavirus itself. According to a preprint paper uploaded to bioRxiv on Feb. 11, the virus will be known as SARS-CoV-2. The group “formally recognizes this virus as a sister to severe acute respiratory syndrome coronaviruses (SARS-CoVs),” the species responsible for the SARS outbreak in 2002-2003. The virus itself was originally given a placeholder name of “2019-nCoV.”

To avoid confusion: 

  • The novel coronavirus is officially named SARS-CoV-2.
  • The disease caused by SARS-CoV-2 is officially named COVID-19

Where did the virus come from?

The virus appears to have originated in Wuhan, a Chinese city about 650 miles south of Beijing that has a population of more than 11 million people. The Huanan Seafood Wholesale Market, which sells fish, as well as a panoply of meat from other animals, including bats, snakes and pangolins, was implicated in the spread in early January.

Prestigious medical journal The Lancet published an extensive summary of the clinical features of patients infected with the disease stretching back to Dec. 1, 2019. The very first patient identified had not been exposed to the market, suggesting the virus may have originated elsewhere and been transported to the market, where it was able to thrive or jump from human to animal and back again. Chinese authorities shut down the seafood market on Jan. 1. 

Markets have been implicated in the origin and spread of viral diseases in past epidemics, including SARS and MERS. A large majority of the people so far confirmed to have come down with the new coronavirus had been to the Huanan Seafood marketplace in recent weeks. The market seems like an integral piece of the puzzle, but researchers continue to test and research the original cause. 

An early report, published in the Journal of Medical Virology on Jan. 22, suggested snakes were the most probable wildlife animal reservoir for SARS-CoV-2, but the work was soundly refuted by two further studies just a day later, on Jan. 23.

“We haven’t seen evidence ample enough to suggest a snake reservoir for Wuhan coronavirus,” said Peter Daszak, president of nonprofit EcoHealth Alliance, which researches the links between human and animal health.

“This work is really interesting, but when we compare the genetic sequence of this new virus with all other known coronaviruses, all of its closest relatives have origins in mammals, specifically bats. Therefore, without further details on testing of animals in the markets, it looks like we are no closer to knowing this virus’ natural reservoir.”

Another group of Chinese scientists uploaded a paper to preprint website biorXiv, having studied the viral genetic code and compared it to the previous SARS coronavirus and other bat coronaviruses. They discovered the genetic similarities run deep: The virus shares 80% of its genes with the previous SARS virus and 96% of its genes with bat coronaviruses. Importantly, the study also demonstrated the virus can get into and hijack cells the same way SARS did.

The ant-eating pangolin, a small, scaled mammal, has also been implicated in the spread of SARS-CoV-2. According to the New York Times, it may be one of the most trafficked animals in the world and it was sold at the Huanan Seafood Market. The virus likely originated in bats but may have been able to hide out in the pangolin, before spreading from that animal to humans. 

All good science builds off previous discoveries — and there is still more to learn about the basic biology of SARS-CoV-2 before we have a good grasp of exactly which animal vector is responsible for transmission — but early indications are the virus is similar to those seen in bats and likely originated from them. 

How many confirmed cases have been reported?

Authorities have confirmed over 76,000 cases as of Feb. 20.

On Feb. 12, Chinese health authorities reported a jump in the amount of cases and deaths in Hubei, the epicenter of the outbreak. Over 13,300 new cases were recorded in Hubei alone, an increase of 700% over the previous day. Chinese authorities had adopted a new clinical method for confirming cases Wednesday, which sees them add “clinically diagnosed cases” to the count, which could help patients receive treatment sooner, according to CNN.   

A cruise ship, the Diamond Princess, stationed off the Japanese port of Yokohama has been put into quarantine after a passenger traveling onboard was found to be infected with SARS-CoV-2. Around 3,700 passengers and crew are on the ship until Feb. 19, and the total number of cases on board has reached at least 621 as of Feb. 20 — the highest anywhere outside China. 

In the US, 15 cases have been confirmed: eight in California, two in Illinois and one each in Arizona, Massachusetts, Texas, Wisconsin and Washington state. Canada has seven confirmed cases. An additional 14 cases were confirmed after evacuation from the Diamond Princess.

The number of discharged patients has climbed to over 18,000.

A full breakdown, as of Feb. 20, is below:

  • China: 75,077 confirmed cases (Hong Kong: 68; Macau: 10)
  • Diamond Princess passengers: 643 confirmed cases
  • South Korea: 104 confirmed cases 
  • Japan: 94 confirmed cases
  • Singapore: 84 confirmed cases    
  • Thailand: 35 confirmed cases 
  • Taiwan: 24 confirmed cases 
  • Malaysia: 22 confirmed cases 
  • Australia: 17 confirmed cases     
  • Germany: 16 confirmed cases 
  • Vietnam: 16 confirmed cases 
  •  US: 15 confirmed cases    
  • France: 12 confirmed cases
  • UK: 9 confirmed cases 
  • United Arab Emirates: 9 confirmed cases
  • Canada: 8 confirmed cases
  • Iran: 5 confirmed cases
  • India: 3 confirmed cases
  • Philippines: 3 confirmed cases
  • Italy: 3 confirmed cases
  • Russia: 2 confirmed cases
  • Spain: 2 confirmed cases
  • Cambodia: 1 confirmed case
  • Nepal: 1 confirmed case 
  • Sri Lanka: 1 confirmed case
  • Egypt: 1 confirmed case
  • Finland: 1 confirmed case
  • Sweden: 1 confirmed case
  • Belgium: 1 confirmed case

You can track the spread of the virus with this handy online tool, which is collating data from a number of sources including the CDC, the WHO and Chinese health professionals. 

How many deaths have been reported?

The death toll has increased to more than 2,100 as of Feb. 20. 

On Feb. 7, Li Wenliang, the 34-year-old Chinese doctor who spoke out about the rising cases of pneumonia in an online chat room during the early days of the outbreak, died as a result of COVID-19. A day later, the first known American death from the illness was announced: A US citizen in Wuhan.

On Feb. 15, France’s health minister reported that a Chinese tourist had succumbed to coronavirus at a Paris hospital a day earlier, the first death outside Asia. Two other deaths have been recorded outside China, one in the Philippines, the other in Japan.  

The death toll surpassed that of the SARS epidemic (severe acute respiratory syndrome) on Feb. 8. That outbreak killed 774 people. On Feb. 9, the death toll surpassed 900, overtaking the death toll of MERS (Middle East respiratory syndrome), a similar coronavirus that has killed 858 people since 2012.

Two Japanese passengers aboard the quarantined Diamond Princess cruise ship, an 87-year-old man and an 84-year-old woman, have died, Japanese network NHK reported on Thursday. The deaths are the first for the cruise ship, which was docked in Yokohama for a two-week quarantine period following a cluster of confirmed infections on board.

Those two viruses have a higher death rate, with SARS-CoV killing about 10% of those infected and MERS-CoV killing about 34%, whereas this virus, SARS-CoV-2, hovers at around 2% to 3%. 

The death toll still pales in comparison to that of influenza — the flu — which, through the first four weeks of 2020, had killed 1,210 in the US alone, according to the CDC.

Protecting against the coronavirus in Wuhan, China.

A pedestrian in the city of Wuhan, China. The virus appears to have originated in Wuhan’s Huanan Seafood Wholesale Market.

Getty Images

How do we know it’s a new coronavirus?

The Chinese Center for Disease Control and Prevention dispatched a team of scientists to Wuhan to gather information about the new disease and perform testing in patients, hoping to isolate the virus. Their work, published in the New England Journal of Medicine on Jan. 24, examined samples from three patients. Using an electron microscope, which can resolve images of cells and their internal mechanics, and studying the genetic code, the team were able to visualize and genetically identify the novel coronavirus.

Understanding the genetic code helps researchers in two ways: It allows them to create tests that can identify the virus from patient samples, and it gives them potential insight into creating treatments or vaccines.

Additionally, the Peter Doherty Institute in Melbourne, Australia, was able to identify and grow the virus in a lab from a patient sample. They announced their discovery on Jan. 28. This is seen as one of the major breakthroughs in developing a vaccine and provides laboratories with the capability to both assess and provide expert information to health authorities and detect the virus in patients suspected of harboring the disease.

How does the coronavirus spread?

This is one of the major questions researchers are still working hard to answer. The first infections were potentially the result of animal-to-human transmission, but confirmation that human-to-human transmission was obtained in late January.

The University of Minnesota’s Center for Infectious Disease Research and Policy reported that health workers in China had been infected with the virus in late January. During the SARS epidemic, this was a notable turning point, as health workers moving between countries were able to help spread the disease.

“The major concern is hospital outbreaks, which were seen with SARS and MERS coronaviruses,” said C. Raina MacIntyre, a professor of global biosecurity at the University of New South Wales. “Meticulous triage and infection control is needed to prevent these outbreaks and protect health workers.”

WHO says the virus can move from person to person via:

  • Respiratory droplets — when a person sneezes or coughs.
  • Direct contact with infected individuals.
  • Contact with contaminated surfaces and objects.

On Feb. 5, Chinese state media reported a newborn had been diagnosed with COVID-19 just 30 hours after birth, opening up the potential for mother-child transmission. Viruses can be transmitted through the placenta, but experts say it’s too early to tell whether this is the case with the novel coronavirus, which is “unlikely” to be passed on in the womb.

A handful of viruses, including MERS, can survive for periods in the air after being sneezed or coughed from an infected individual. Although recent reports suggest the novel coronavirus may be transmitted in this way, the Chinese Center for Diseases Control and Prevention have reiterated there is no evidence for this. Writing in The Conversation on Feb. 14, virologists Ian Mackay and Katherine Arden explain “no infectious virus has been recovered from captured air samples.”

How is the world combating the spread? 

In Wuhan, authorities rushed to build a thousand-bed hospital to treat coronavirus patients as the province struggles with hospital bed shortages. It began taking patients on Feb. 4.

China shut down Wuhan to reduce the spread of the virus, canceling transportation leaving the city starting at 10 a.m. Jan. 23. The travel restrictions were extended to four other cities (Huanggang, Ezhou, Chibi and Zhijiang) later that day, and constraints were announced in eight more cities on Jan. 24 — impacting more than 35 million people. 

The restrictions were enforced during a busy travel period for China, when citizens typically travel for the Lunar New Year. Major public events Chinese capital Beijing were canceled, and both Beijing’s Forbidden City and Shanghai’s Disneyland closed down from Jan. 25. All of the restrictions and closures will last indefinitely.

The scale of the global efforts to contain the disease is immense. Hong Kong closed many public facilities on Jan. 28 and has prevented traveling between mainland China. The US announced sweeping border control measures at 20 ports of entry and has been considering cancelling flights to and from the outbreak epicenter in Wuhan. Esports tournaments have been postponed, Shanghai and Hong Kong Disneyland has closed, Olympic women’s soccer tournaments have been moved entirely, and McDonald’s has shuttered thousands of locations across China where the virus is spreading.

British Airways on Jan. 29 suspended all flights to and from mainland China “for the next few days,” a spokesperson confirmed via email. American Airlines and Delta are also suspending service to mainland China, though Delta will continue to operate flights until Feb. 5 for customers looking to exit China. The national airline in Australia, Qantas, announced the suspension of flights from Sydney to Beijing and Sydney to Shanghai from Feb. 9. New Zealand’s carrier, Air New Zealand, suspended daily flights to Shanghai on Feb. 1.

Cruise ships have also begun denying passengers, with Royal Caribbean announcing Feb. 7 that it will deny entry to “all holders of China, Hong Kong and Macau passports, regardless of residency.” It’s also barring anyone who has travelled to China, Hong Kong or Macau in the 15 days prior to boarding; and anyone who has come within six feet of someone from China, Hong Kong or Macau 15 days prior; and anyone with fever or low blood oximetry. Norwegian Cruise Line is denying entry to anyone who has been through China, Hong Kong and Macau within 30 days prior to the cruise, and to anyone holding a passport from those places. 

On Jan. 31, US Secretary of Health and Human Services Alex Azar declared a public health emergency citing the nation’s intention to protect and respond to the outbreak, while noting “the risk to Americans remains low.” Australia and Japan followed suit. On Feb. 4, Britain’s Foreign Office and the French Foreign Ministry warned citizens to evacuate China to lower their risk of infection.   

Some of the world’s largest tech firms have been adversely affected by the outbreak, shutting down stores and factories in China. Barcelona’s Mobile World Congress, the world’s largest phone trade show set to begin Feb. 24, took the unprecedented step of cancelling the entire show. Electronics giant Apple announced on Feb. 17 it would now miss its revenue guidance for the March quarter, as the virus slows work. “Worldwide iPhone supply will be temporarily constrained,” Apple said, after production facilities were “ramping up more slowly” than anticipated.  

Speaking to the media on Feb. 17, Shigeru Omi, the chief director of the Japan Community Health Care Organization, suggested the Olympics could be disrupted or even cancelled, depending on how the virus continues to spread and evolve over the next few months.

“Whether the virus is under control by the time of the Olympics is anyone’s guess,” he said.

Cancellations have come thick and fast in the video game industry, which has seen Sony Interactive Entertainment pull out of one of the biggest conventions in the US, PAX East. The company was scheduled to show off one of its most highly-anticipated titles, The Last of Us Part II, but pulled the pin on attendance citing coronavirus concerns. On Feb. 20, Sony and Facebook Gaming announced they would not be attending this year’s Game Developer’s Conference in San Francisco

Coronavirus that causes SARS, seen in an electron microscope

An electron microscopy image of the coronavirus that causes SARS. 

Getty Images

How infectious is coronavirus?

A widely shared Twitter thread by Eric Feigl-Ding, a Harvard University epidemiologist, suggests the new coronavirus is “thermonuclear pandemic level bad” based on a metric known as the “r nought” (R0) value. This metric helps determine the basic reproduction number of an infectious disease. In the simplest terms, the value relates to how many people can be infected by one person carrying the disease. It was widely criticized before being deleted.

Infectious diseases such as measles have an R0 of 12 to 18, which is remarkably high. The SARS epidemic of 2002-2003 had an R0 of around 3. A handful of studies modeling the COVID-19 outbreak have given a similar value with a range between 1.4 and 3.8. However, there is large variation between studies and models attempting to predict the R0 of novel coronavirus due to the constantly changing number of cases. 

In the early stages of understanding the disease and its spread, it should be stressed these studies are informative, but they aren’t definitive. They give an indication of the potential for the disease to move from person-to-person, but we still don’t have enough information about how the new virus spreads. 

“Some experts are saying it is the most infectious virus ever seen — that is not correct,” MacIntyre said. “If it was highly infectious (more infectious than influenza as suggested by some) we should have seen hundreds, if not thousands of cases outside of China by now, given Wuhan is a major travel hub.”

China has suggested the virus can spread before symptoms present. Writing in The Conversation on Jan. 28, MacIntyre noted there was no evidence for these claims so far but does suggest children and young people could be infectious without displaying any symptoms. This also makes airport screening less impactful, because harboring the disease but showing no signs could allow it insidiously spread further.

Should you be worried?

As the virus has continued to spread, it’s easy to get caught up in the fear and alarmism rampantly escalating through social media. There is misinformation and disinformation swirling about the effects of the disease, where it’s spreading and how. Experts still caution the virus appears to be mild, especially in comparison to infections by other viruses, like influenza or measles, and markedly lower death rates than previous coronavirus outbreaks.

CNET has put together a fact check about some of the rumors and myths that have been spreading.

WHO declares a public health emergency

On Jan. 30, the World Health Organization declared a public health emergency of international concern over the coronavirus outbreak. Tedros Adhanom Ghebreyesus, the director-general of the WHO, said the organization is working with national and international public health partners to get the outbreak under control. 

The WHO also issued recommendations to prevent the spread of the virus and ensure a “measured and evidence-based response.”

In the fall, an emergency committee met regarding the Ebola virus epidemic in the Democratic Republic of the Congo. The meeting outlined key strategies and commitments to strengthen and protect against the spread of the disease.

What are the symptoms?

The new coronavirus causes symptoms similar to those of previously identified disease-causing coronaviruses. In currently identified patients, there seems to be a spectrum of illness: A large number experience mild pneumonia-like symptoms, while others have a much more severe response.

On Jan. 24, prestigious medical journal The Lancet published an extensive analysis of the clinical features of the disease.

According to the report, patients present with:

  • Fever, elevated body temperature.
  • Dry cough.
  • Fatigue or muscle pain.
  • Breathing difficulties.   

Less common symptoms of coronavirus include:

  • Coughing up mucus or blood.
  • Headaches.
  • Diarrhea.
  • Kidney Failure.

As the disease progresses, patients also come down with pneumonia, which inflames the lungs and causes them to fill with fluid. This can be detected by an X-ray. 

Is there a treatment for coronavirus?

Coronaviruses are hardy organisms. They’re effective at hiding from the human immune system, and we haven’t developed any reliable treatments or vaccines to eradicate them. In most cases, health officials attempt to deal with the symptoms.

“There is no recognized therapeutic against coronaviruses,” Mike Ryan, executive director of the WHO Health Emergencies Programme, said during the Emergency Committee press conference on Jan. 29. “The primary objective in an outbreak related to a coronavirus is to give adequate support of care to patients, particularly in terms of respiratory support and multi-organ support.”  

That doesn’t mean vaccines are an impossibility, however. Chinese scientists were able to sequence the virus’ genetic code incredibly quickly, giving scientists a chance to study it and look for ways to combat the disease. According to CNN, researchers at the US National Institutes of Health are already working on a vaccine, though it could be a year or more away from release.

Notably, SARS, which infected around 8,000 people and killed around 800, seemed to run its course and then mostly disappear. It wasn’t a vaccine that turned the tide on the disease but rather effective communication between nations and a range of tools that helped track the disease and its spread.

“We learnt that epidemics can be controlled without drugs or vaccines, using enhanced surveillance, case isolation, contact tracking, PPE and infection control measures,” MacIntyre said.

A handful of organizations and research institutes have started work on vaccines, according to Global Times. 

In addition, China is running clinical trials on the experimental antiviral drug remdesivir, which was originally developed to treat Ebola. Remdesivir was also given to a US patient in Washington state whose symptoms worsened. In that case, doctors made a “compassionate use” request to the Food and Drug Administration. Those allow people to try experimental drugs outside of clinical trials, usually in emergency situations.

China is also running a small clinical trial of Kaletra, an anti-HIV drug, according to The Guardian. 

Developing new drugs requires time and resources, so “while you’re waiting for the new miracle drug, it’s worthwhile looking for existing drugs that could be repurposed” to treat new viruses, Stephen Morse, a professor at Columbia University’s Mailman School of Public Health, told Live Science

In a press conference on Feb. 11, the WHO said a vaccine could be ready in 18 months.

How to reduce your risk of coronavirus

With confirmed cases now seen across the globe, it’s possible that SARS-CoV-2 may spread much further afield than China. The WHO recommends a range of measures to protect yourself from contracting the disease, based on good hand hygiene and good respiratory hygiene — in much the same way you’d reduce the risk of contracting the flu. The novel coronavirus does spread and infect humans slightly differently to the flu, but because it predominantly affects the respiratory tract, the protection measures are quite similar.

Meanwhile, the US State Department on Jan. 30 issued a travel advisory with a blunt message: “Do not travel to China.” An earlier warning from the CDC advised people to “avoid nonessential travel.”

A Twitter thread, developed by the WHO, is below.

You may also be considering buying a face mask to protect yourself from contracting the virus. You’re not alone — stocks of face masks have been selling out across the world, with Amazon and experiencing shortages. Reporting from Sydney in January, I found lines at the pharmacy extending down the street. 

The risk of contracting the virus outside of China remains low, but if you’re considering buying a mask, you’ll want to know exactly which face mask you should be looking for. Disposable masks can protect any large droplets from entering the mouth or nasal passage but a respirator mask is far more effective. CNET’s Wellness team has put together a comprehensive guide to which masks you should buy.

Originally published last month and updated frequently with new developments.