What would it be like to live in a city under quarantine because of a new virus? Most public spaces — from schools to shops, movie theatres, workplaces and churches are closed until further notice. Masks are required if you go in public, and handwashing stations pop up all over the neighborhood. You would like to go visit an elderly family member with pneumonia in a neighboring city, but public transportation is shut down. You have enough food to last a couple of weeks, but after that you are hoping either the quarantine will be lifted or that your community and government will be there to help. You carefully monitor yourself and family members for any symptoms, but it’s confusing. Do they have a simple cold, or something more serious?
Thankfully, your community is peaceful and neighbors support each other. You trust that the medical system will do its best to help you and your family if you get sick, but you hear rumors that they are running short on supplies and some doctors and nurses are getting sick too. The government is rushing to build a special hospital just for people who need to be quarantined. This offers some hope, but the uncertainty of when the crisis will end weighs heavily on your mind.
This is the current reality for 35 million people in and around the city of Wuhan, China (almost the same population size as the state of California). At the time of writing, a new coronavirus, called 2019-nCoV, has infected over 800 people, and killed 26. The World Health Organization says that so far the situation does not constitute its special designation of “Public Health Emergency of International Concern” (PHEIC), but that may change in coming days. There have only been five infectious disease crises designated as PHEICs since the term was invented after the SARS epidemic of 2002. These included two Ebola epidemics (2014 and 2018), a Polio resurgence in 2014, 2009 Swine flu, and Zika virus in 2016.
How does this happen? New diseases seem to come from nowhere, and spread quickly. Why can’t we see new outbreaks coming?
Most viruses that infect humans, are actually more at home in other animals. Viruses each have reservoirs, or species that they are well-adapted to. A reservoir species can get sick from the virus, but it is usually not serious. Humans are the reservoir species for some viruses like respiratory syncytial virus (RSV). When children get RSV it can become serious, but most of the time it presents as a simple cold.
Viruses are mutating all the time. The vast majority of the time the mutations either make the virus weaker or have no real effect at all. But occasionally a virus mutates in a way that allows it to infect a new species. The more two species interact with each other, the more likely this is to happen. That’s why the new coronavirus in China is thought to be linked to trade in illegal meat. An animal that had a new version of the virus was likely killed and infected someone who processed the meat. When a virus is able to infect a new species, it is called spillover.
Most of the time there is spillover, the cases don’t spread among humans as an epidemic. That only happens if the new version of the virus is well-adapted enough to not only infect a human, but copy itself enough times that the virus can be spread to others too. Unfortunately, that is what we experienced with Ebola, different influenza strains, and now this new coronavirus. Scientists are constantly monitoring countries for new viruses, so they can be stopped before they spread globally, but when and where it will happen next is very hard to predict.
You can help stop the spread of infectious diseases by staying home when sick, washing your hands regularly with soap, and practicing good hygiene when coughing or sneezing. It is good to be prepared for a serious outbreak by having a supply of food, soap and hand sanitizer, and possibly keeping some masks and gloves on hand. Masks should be those labeled as N95 respirators, not just surgical masks. Surgical masks don’t prevent infection from viruses very well on their own. Thankfully the new coronavirus is not spreading in Utah right now, but this epidemic should be a cautionary tale for us to be prepared and to respectfully avoid infecting others when we are sick.