You may have heard about coronaviruses recently. Unfortunately, you'll probably be hearing a lot more. They're a type of virus that normally infects only animals, but they are now starting to infect people. And they can kill.
Right now, one coronovirus, dubbed 2019 novel coronovirus or 2019-nCoV, is causing an outbreak of pneumonia in China. As of late January, over 2,000 cases have been confirmed, with 56 deaths. Cases have been reported in 13 locations outside of China, including five cases in the United States, all in people who had travelled to Wuhan, China.
The CDC describes the immediate health risk to the general American public as “low at this time.” However, there is a great deal of uncertainty surrounding the outbreak and the situation remains fluid. It's not clear yet how easily or quickly this virus is spreading between people, but when a virus makes the jump from infecting animals to infecting people, it is always concerning. People have had little previous exposure to the virus and therefore little chance to build up immunity to it.
It's concerning when a virus makes the jump from animals to humans. With little previous exposure to it, people haven't had a chance to build up immunity.
Coronaviruses have been around for a long time but have largely been ignored because they mostly infect animals. This changed in 2002, when a severe, unusual outbreak of pneumonia began in Guangdong province in China. It was eventually brought under control, but not before more than 8,000 people were infected and over 750 died. Most cases were in Hong Kong and China. Twenty to 30 percent of infected people required mechanical ventilation and 10 percent died, with higher fatality rates in older patients and those with other medical issues. The disease was named SARS, short for severe acute respiratory syndrome.
While the virus did spread from person to person, its natural reservoir appears to be in bats. Somehow, it had managed to jump from bats to people.
In 2012, a different coronavirus made the jump from animals to humans, this time in Saudi Arabia, causing another epidemic of respiratory disease. The virus was distinct from the one that caused SARS and the disease that it caused was named Middle East respiratory syndrome (MERS). Nearly 2500 cases and over 800 deaths were reported, with most cases coming in Saudi Arabia. The virus is presumed to normally live in bats, though there have been apparent cases of transmission from dromedary camels.
While the SARS and MERS epidemics did spread beyond their original location, most cases occurred close to home. Of course, every outbreak is unique and the current one is fairly new, but if it runs like the other two, the U.S. may be spared the worst of its fury, though with three different coronavirus outbreaks in the last 20 years or so, it's likely that there will be more.
A Viewpoint by Anthony S. Fauci, MD, Director of the National Institute of Allergy and Infections Diseases (NIAID)i, detailing all three coronavirus outbreaks has recently been published in JAMA.