Coronavirus: What We Know.

Updated at 6pm ET on January 31.

A new coronavirus that originated in the city of Wuhan, China, at the end of 2019 has now sickened thousands of people across China and killed more than 200, with over 100 confirmed cases in other countries around the world—including six confirmed cases in the US.

SPH discussed the outbreak with two faculty members who are experts in infectious disease. Davidson Hamer is a professor of global health at SPH and of infectious diseases at the School of Medicine. Jean van Seventer is a clinical associate professor of environmental health at SPH, with a focus on animal-to-human infectious disease transmission.

They co-teach PH 825, a core course in emerging infectious diseases at SPH that will definitely be adding this new virus to the curriculum.

SPH: What is the new coronavirus?

van Seventer: 2019-nCoV (2019 novel coronavirus) belongs, as its name indicates, to the large family of coronaviruses. There are seven coronaviruses that can infect people, including some that are agents of the common cold, as well as severe acute respiratory syndrome (SARS-CoV) and Middle East respiratory syndrome (MERS-CoV). All are thought to have originated in animals.

Where did it come from?

van Seventer: The genetic sequence of 2019-nCoV is very similar to SARS-CoV, suggesting that it too originated in bats. We do not know whether 2019-nCoV entered the human population directly from bats, or from bats to another animal and then to humans, but the striking similarity in sequence between 2019-nCoV virus isolates from multiple patients suggests whatever the path of spillover from animal to humans, entry of the virus into the human population occurred very recently.

How serious is this disease? How worried should people around the world be?

Hamer: We still don’t know a lot about the severity of this disease. We can safely say that a proportion of patients have been ill enough to require hospitalization and intensive care support. We don’t know yet what the case-fatality is, but clearly some people are dying from it. We do know that a good proportion of those who have died were older—50 years old and above—and/or had other medical conditions that may have increased their risk. On the other hand, there’s some evidence that at least a subset of people who are dying were young and healthy.

How does it spread?

Hamer: It’s clear now that there’s person-to-person spread, and that seems to be mainly through respiratory droplet—through people coughing and sneezing but also potentially through contact with surfaces that have been contaminated by respiratory droplets. Given what we learned about SARS, contact with other fluids including feces may turn out to be a potential mode of transmission of this virus as well. Like SARS, some patients are presenting with diarrhea, which may turn out to be full of contagion—we don’t know yet. The first case diagnosed in the US had molecular evidence of 2019-nCoV in his stool, although this does not prove that it was live virus. Nevertheless, this raises the possibility that the virus might be able to be transmitted by body fluids other than those from the respiratory tract.

van Seventer: 2019-nCoV appears to enter cells using the same receptor as SARS, making it likely that it spreads from both the respiratory and gastrointestinal systems.

Hamer: There’s also evidence now of possible spread before someone has symptoms. A Shanghai resident at a business meeting in Germany did not appear to have symptoms until the plane ride home to China, but four Germans who were at the meeting subsequently became sick and were confirmed to have 2019-nCoV. This has implications for screening: Symptom-based screening in airports is going to capture many, but perhaps not all, of the cases.

van Seventer: The first case of a person coming back to the US from Wuhan, China, and transmitting the virus to their spouse was confirmed in Chicago. The second patient had been monitored closely by the Cook County Department of Public Health, which is now monitoring any close contacts who were possibly exposed to 2019-nCoV by either of these two patients. Awareness of health professionals is up across the country.

Hamer: The more we do to identify infected patients immediately and isolate them, the less person-to-person transmission is going to occur. It’s going to happen, but as public awareness of the disease grows and people are encouraged to seek treatment, that will hopefully greatly reduce the risk of onward transmission.

van Seventer:  As with the beginning of any epidemic, particularly when a new pathogen is involved, cases can go unrecognized because health professionals are not on the lookout for them. Then, as health officials become more aware of the problem and surveillance for cases is enhanced, there is an increase in case recognition, which is at least part of what we are seeing here.

How are governments and other authorities responding?

Hamer: I think China’s response has been remarkable. It’s been vigorous and intense ever since figuring out that there was an outbreak. It’s currently the Lunar New Year, and the government is actually extending the timing of the New Year celebration, saying, ‘Celebrate in February, not now!’ because this is a time when people are moving all over China. It’s terrible timing—or good timing, if you’re the virus—so I’ve been really impressed by China’s response. Lots of governments are really mobilizing, but the most important one is China.

van Seventer: The Chinese government’s response to SARS was, particularly in the beginning, extremely opaque and it really hindered efforts to prevent global spread of the disease. China took a lot of heat for its lack of transparency around SARS, and its response now appears to be much more proactive and transparent in its interactions with the global community.

The WHO has now declared this a public health emergency of international concern (PHEIC), which basically allows for the international movement of resources and collaboration of efforts to prevent more global spread. These regulations were updated after SARS (because it became obvious that you needed that kind of coordination), and since then this is the sixth time a PHEIC has been declared.

The ongoing Ebola outbreak in the Democratic Republic of the Congo was also declared a PHEIC, so this is the first time that there have been two PHEICs occurring at the same time.

Hamer: There’s a whole string of airlines shutting down their flights to and from China, and where flights are coming in there are airport screenings. Travelers are being screened based on where they’re coming from, and if they have symptoms—coughing, fever, and/or difficulty breathing.

In the US, the Centers for Disease Control and Prevention (CDC) reopened its Emergency Operations Center for this new virus response. The public health control measures that the US is putting in place should do a lot to prevent further spread.

What can people in the US do to protect themselves?

​Hamer: Healthcare workers in China are at high risk, as is anyone who’s traveled to China within 14 days, and any healthcare workers who have been exposed to someone who’s traveled to China. I would not recommend travel to any part of China right now, unless you’re a medical worker and you want to go help with the outbreak response.

Hospitals need to be ready and prepared to put people who may have 2019-nCoV in respiratory isolation and have protocols in place to quickly act and respond. The big thing is, if you see a patient in an emergency room or primary care, you need to take a travel history. We learned that with Ebola, where a travel history wasn’t taken right away with a man who came back from Liberia to Dallas and exposed a bunch of healthcare workers, a few of whom became ill.

In general, if you’re touching surfaces in public places or shaking hands, it’s a good idea to wash your hands. Good hand hygiene is always a good idea.

van Seventer: The CDC recommends  to wash your hands often with soap and water for 20 seconds, and when you cough or sneeze, cover your mouth and nose with a tissue or sleeve—not your hand.  People should be aware of the possibility of fecal transmission as well, and should take that into consideration when thinking about how to protect themselves from 2019-nCoV infection.

Hamer: There is no place for stigmatizing individuals from China, since the highest risk of 2019-nCoV is in those who have recently been to China, especially Hubei Province where Wuhan City is situated. There are many Chinese people studying and working in the US who have not traveled to China recently, and many Chinese Americans who haven’t traveled to China recently, and they shouldn’t be treated any differently from anyone else.

Interview conducted by Michelle Samuels.