Scientific explanation of 2019-nCOv outbreak
A novel coronavirus, first identified in Wuhan, Hubei Province, China, has made its way across the world, infecting more individuals each day. As of Feb. 5, the Wuhan coronavirus, or 2019-nCOv, has killed 564 people worldwide, with all but two fatalities occurring in mainland China, according to CNN.
Over 28,000 people in more than 25 countries have been infected and, in China, almost 60 million people remain under lockdown, unable to leave the country. There are 11 confirmed cases in the U.S., six of which are in California. According to the Los Angeles Times, four of those are in the San Francisco Bay Area.
Although the exact cause of 2019-nCOv has not been confirmed, professionals widely agree that it is zoonotic, meaning it is transmitted between animals and people. Dean Blumberg, the chief of pediatric infectious diseases at UC Davis Children’s Hospital, has specified that it most likely arose from a mutated virus found in bats. Human contact with bats would have occurred at one of the many live animal markets in Wuhan. Post-contact, the virus mutated to infect humans and then mutated again to be transmitted
“It most likely came originally from bats, either directly to humans or through an intermediate host,” said Samuel Díaz Muñoz, an assistant professor in the department of microbiology and molecular genetics, via email.
It is believed that the first human contracted this specific coronavirus in November of 2019, but the disease was not identified as a novel coronavirus until December, according to Blumberg. Since then, people traveling to and from China have become infected and have transmitted the virus. Compared to other coronavirus outbreaks, the mortality rate for 2019-nCOv is fairly low and only between 1-4% of individuals throughout the world are suffering from infection.
Li Wenliang, one of the first doctors in China that tried to warn the public about 2019-nCOV, was silenced by the Chinese police for being a whistleblower. He died on Feb. 7 after contracting the virus himself, according to the New York Times. Chinese citizens are expressing their anger towards the government and their gratitude for Wenliang on social media platforms.
“It’s quite traumatic what’s happening in China,” said Christine Kreuder Johnson, a professor of epidemiology. “In terms of both the number of cases and loss of life, and then the very strict measures that they’re implementing to protect the rest of the world.”
At first, the only cases in the U.S. had been imported from abroad, but the first confirmed case of person-to-person contact was verified on Jan. 30, according to CNN.
The majority of infected people have been adults and the most severe cases have been in older adults, Blumberg said. In healthy, younger individuals, the cases have been milder. Many of the individuals who have died had other underlying health issues.
“About 30% [of infected people] will develop a life-threatening viral pneumonia end-stage lung disease,” Díaz Muñoz said. “Most of these people are going to be 65 [and] over or people who have other complicating conditions with their health.”
Currently, the Center for Disease Control (CDC) considers the immediate health risk for most individuals in the U.S. to be low. The CDC and other public health agencies want to contain the outbreak and prevent the sustained spread of the virus in the U.S., said Cindy Schorzman, the medical director of UC Davis Student Health and Counseling Services, via email.
Although this coronavirus may appear to be affecting a significant amount of people, other viruses, including preventable ones such as influenza, cause more deaths. The CDC reports that, as of Jan. 18, there have been 15 million cases of flu and 8,200 deaths from flu in the U.S. in the 2019-20 influenza season.
Coronaviruses, like 2019-nCOv, are large, positive-stranded RNA genomes that cause respiratory illnesses in humans, Díaz Muñoz said. Many coronaviruses are fairly common and only lead to mild, short-lived illnesses. Their symptoms resemble the common cold, such as low-grade fevers, coughs and sore throats. Some coronaviruses, however, such as MERS, SARS and now the 2019-nCOv, cause more extreme symptoms.
The Wuhan Coronavirus can display a wide range of symptoms in humans, Schorzman said. Some infected individuals have reported having milder respiratory symptoms, while others develop severe, life-threatening symptoms. By infecting the upper and lower respiratory tract, 2019-nCoV can lead to pneumonia and difficulty breathing.
Since only the most severe cases of the coronavirus are diagnosed, people showing more minor symptoms can spread the virus unknowingly. This makes containment challenging. The incubation period of the virus seems to be between 2–14 days, so individuals may have the virus for up to two weeks before showing symptoms, Schorzman said.
“On the one hand, in the majority of healthy people, it only causes a cold, but on the other hand in other people, it can be severe and result in death,” Blumberg said. “Everyone in the world is susceptible to it. It is a new virus so nobody has immunity to it.”
This virus can be spread via the respiratory tract when infected individuals cough or sneeze. Mucus droplets, which can travel up to six feet, can infect anyone within the distance and contaminate many surfaces, Blumberg said.
Since no treatment is available yet, the most fool-proof way to avoid getting sick is to avoid areas where infected people are or have been, according to Blumberg. Many countries have instilled travel restrictions to and from China and are quarantining infected individuals. Even in California, two military bases, one of which is the Travis Air Force Base in Vacaville, are housing infected individuals.
Additionally, following simple hygiene habits is the best way to stay healthy, Schorzman said. This includes washing one’s hands with soap and water often for at least 20 seconds, using alcohol-based hand sanitizers, avoiding touching one’s face with unwashed hands, avoiding close contact with sick people and disinfecting frequently touched surfaces.
Any person that suspects they have 2019-nCoV should stay home to avoid spreading the virus, Schorzman said. Davis community members should contact Student Health and Counseling Services or their primary medical provider for advice prior to going in.
“UC Davis Student Health, based on CDC guidelines, has developed additional screening, by phone and at our front desks, and has implemented additional protocols to help identify possible cases of coronavirus to provide optimal care for those with symptoms and to protect other patients and staff,” Schorzman said.
Students who have concerns about family members or friends in at-risk areas or are anxious about what they see in the news can contact Mental Health Crisis Consultation Service. They can also contact the Student Health and Wellness Center for support, Schorzman said.
In addition to the virus’ direct health impacts, the quality of life of millions of people in China has been impacted. Travel restrictions are in place, the city of Wuhan is in lockdown and the economy has taken a significant hit, Díaz Muñoz said.
Diaz Muñoz emphasized the notion that it is important to not discriminate against people based on where a virus originates, as race did not play a role in this outbreak’s occurrence.
“Viruses infect cells and don’t particularly ‘care’ about these particular human traits,” Díaz Muñoz said. “So while there is definitely a geographic origin to viral outbreaks, these other human social markers are not particularly useful, and indeed can be harmful, for preventing spread.”
Significant efforts and research to develop a vaccine for 2019-nCoV have begun, including at the National Institutes of Health (NIH), Schorzman said. Vaccines for viruses, however, can take years to develop before they are effective.
“There are some drugs that have been tested in mice that are effective against related coronaviruses that could very well be effective against the Wuhan coronavirus,” Díaz Muñoz said. “There is also the possibility to use cells or serum from infected people that have recovered to treat newly infected people, as was done with Ebola.”
It is hard to estimate how much longer the virus will continue to severely impact people, Díaz Muñoz said. Certain viruses remain in human populations for long periods of time, but others sometimes return to their original, animal hosts and are not heard of for years until they reemerge in the human population.
With today’s scientific advancements, including sequencing technologies and open data sharing, researchers can identify viruses early on and can better track their spreads. Many viruses can be caught early and will not amount to an outbreak, Díaz Muñoz said.
“We are in the best position we’ve ever been to know what we are dealing with in real-time,” Díaz Muñoz said. “So it’s important to keep this in mind and not to panic based on sensationalist media headlines.”
Students at UC Davis should look at this virus outbreak as an educational opportunity, Díaz Muñoz said. Biology students can look at the sequences and data on infections and mortality. Students in social sciences can study the effects that the closing off of cities has on people, and students interested in economics can understand the impacts the virus has on people’s livelihoods.
“We can learn from previous similar outbreaks in the recent past,” Díaz Muñoz said. “Students and the community can ask, ‘What can we do better?’ How are you going to be changemakers?”
Written by: Margo Rosenbaum — science@theaggie.org
