Robert Rodriguez/CNET
A never-before-seen virus first detected in the Chinese city of Wuhan has claimed over 130 lives and infected almost 6,000 Chinese citizens with a pneumonia-like illness, according to the country’s National Health Commission. The virus, known as 2019-nCoV, was first reported to the World Health Organization on Dec. 31 and has been under investigation since. Chinese scientists have linked the disease to a family of viruses known as coronaviruses, which include the deadly SARS and Middle East respiratory syndrome.
On Jan. 23, a special WHO committee decided it was still too early to declare a public health emergency on a global level, however, authorities around the world are taking steps to guard against the spread of 2019-nCoV. Travel limitations to and from mainland China have been imposed by Hong Kong, the US announced increasing screening measures at 20 different ports of entry and further spread has been detected in Germany and Japan. Japan has evacuated approximately 200 people from Wuhan as of Tuesday and Australia announced it would evacuate citizens from Wuhan and quarantine them on nearby Christmas Island.
The situation is rapidly evolving. We’ve collated everything we know about the mystery virus, what’s next for researchers and some of the steps you can take to reduce your risk.
Watch this:
Deadly coronavirus detected in the US
1:41
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 around their viral envelope.
Coronaviruses contain a strand of RNA within the envelope and, as a virus, cannot 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 the door open with C4. Once inside, they turn the cell into a virus factory, using its molecular conveyor belt to produce more viruses, which are then shipped out of the cell. The virus progeny infect other cells and the cycle starts anew.
Typically, these types of viruses are found in animals ranging from livestock and household pets to wildlife such as bats. 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 SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome) outbreaks in the last two decades. These viruses were easily transmitted from human to human. 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.
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 sells fish, as well as a panoply of meat from other animals, including bats and snakes. After infections were linked to the marketplace, Chinese authorities shut it down 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.
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.
An early report, published in the Journal of Medical Virology on Jan. 22, suggested snakes were the most probable wildlife animal reservoir for 2019-nCoV but the work was soundly refuted but two further studies just a day later, on Jan. 23.
Here’s a study refuting the evidence for the snake as a #coronavirus reservoir. Suggests that the closest coronavirus relatives are found in bats (bats were also considered the reservoir for SARS in 2003)https://t.co/gRHWIdwMFX
— jackson ryan 🙏 (@dctrjack) January 23, 2020
“We haven’t seen evidence ample enough to suggest a snake reservoir for Wuhan coronavirus (2019-nCoV),” 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.
All good science builds off previous discoveries — and there is still a lot to learn about the basic biology of 2019-nCoV 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. A report by the New York Times on Jan. 28 suggested the Chinese horseshoe bat could be the main culprit.
How many confirmed cases have been reported?
Authorities have confirmed over 5,900 cases as of Monday. The bulk are in China, but cases have been confirmed in Thailand, Japan, South Korea, Malaysia, Sri Lanka, Vietnam, Cambodia and Nepal. In Europe, Germany and France are the only two countries with confirmed cases. Australia has seen five cases as of Tuesday.
In the US, five cases have been confirmed: Two in California and one each in Washington, Illinois and Arizona. Canada has two confirmed cases, one in Ontario and one in British Columbia.
There are almost 7,000 suspected cases.
Here’s the breakdown as it stands:
- China: 5,997 confirmed cases (Hong Kong: 8; Macau: 7)
- Thailand: 14 confirmed cases
- Taiwan: 8 confirmed cases
- Japan: 7 confirmed cases
- Singapore: 7 confirmed cases
- Malaysia: 7 confirmed cases
- US: 5 confirmed cases
- Australia: 5 confirmed cases
- South Korea: 4 confirmed cases
- Germany: 4 confirmed cases
- France: 4 confirmed cases
- Vietnam: 2 confirmed cases
- Canada: 2 confirmed cases
- Cambodia: 1 confirmed case
- Nepal: 1 confirmed case
- Sri Lanka: 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, WHO and Chinese health professionals. (Note: There may be differences in our reports and the tracking tool.)
How many deaths have been reported?
The toll now stands at 132.
No deaths have been recorded outside of China as yet and Chinese state media say 1,200 cases are considered critical.
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?
In short, science!
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 has followed was obtained in late January.
On Jan. 20, the University of Minnesota’s Center for Infectious Disease Research and Policy reported that health workers in China had been infected with the virus. 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,” MacIntyre said. “Meticulous triage and infection control is needed to prevent these outbreaks and protect health workers.”
There is some suggestion the virus can spread before symptoms appear, according to a report by the BBC citing Chinese officials. The incubation period — when the virus is building up in the body — can last between one to 14 days without a patient realizing they are infected. However, it must be stressed, experts still aren’t sure how infectious this period is.
How is China combating the spread?
In Wuhan, authorities are rushing to build a thousand-bed hospital to treat coronavirus patients as the province struggles with hospital bed shortages. It’s aiming to open the facility on Feb. 3, giving construction workers 10 days to get it ready.
China shut down Wuhan to reduce the spread of the virus, canceling transportation leaving the city starting at 10 a.m. Thursday. 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 Friday — 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, Olympic women’s soccer tournaments have been moved entirely and McDonald’s has shuttered thousands of locations across China where the virus is spreading.
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 has been widely criticized.
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 2019-nCoV 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 Tuesday, MacIntyre noted there was no evidence for these claims so far but does not 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.
WHO does not declare a public health emergency
Tedros Adhanom Ghebreyesus, the director-general of the World Health Organization, convened an emergency committee on Jan. 22 and Jan. 23 to determine whether this new virus constitutes a public health emergency. The committee decided that it was still too early to declare a public health emergency of international concern.
“If WHO declares a public health emergency of international concern, it enables WHO greater powers for disease control using the International Health Regulations,” MacIntyre said.
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.
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.
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 and was present in all 41 cases studied.
Is there a treatment for coronavirus?
Coronaviruses are notoriously hardy organisms. They’re effective at hiding from the human immune system, and we haven’t developed any reliable treatments or vaccines that can 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 Wednesday. “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.
Scientists are racing to develop a vaccine against the new #coronavirus. China’s CDC, Shanghai-based Stemirna Therapeutics Co., US’ Johnson & Johnson, Moderna Therapeutics, and Inovio Pharmaceuticals are all working quickly to develop a vaccine. pic.twitter.com/bwiUPvSWJ0
— Global Times (@globaltimesnews) January 29, 2020
How to reduce your risk of coronavirus
With confirmed cases now seen in the US, Thailand, Japan, South Korea and potentially Australia, it’s possible that 2019-nCoV could be spreading much further afield. 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.
Meanwhile, the US State Department has issued a travel advisory, urging people to “exercise increased caution in China.” A warning from the CDC advises people to “avoid nonessential travel.”
A Twitter thread, developed by the WHO, is below.
This story was originally published Jan. 19 and is updated frequently as new information becomes available.