Coronavirus explained: Everything we know as cases rise above 70,000 – CNET

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.

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.

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. 

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.

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.

How do we know it’s a new 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 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.   

On Feb. 12, GSMA, the organization responsible Mobile World Congress, said it’s calling the event off due to the number of companies withdrawing following the outbreak of coronavirus. Several notable tech companies — including LG, ZTE, Samsung, Amazon, Ericsson, Nvidia, AT&T and others  — had already decided to scale back their presence or skip the show all together. 

How infectious is coronavirus?

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.”  

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. 

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 Walmart.com 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.