An outbreak of respiratory illness caused by a novel (new) coronavirus (termed “2019-nCoV”) that was first detected in Wuhan City, Hubei Province, China and which continues to expand. Chinese health officials have reported hundreds of infections with 2019-nCoV in China, including outside of Hubei Province. A number of countries, including the United States, have been actively screening incoming travelers from Wuhan and human infections with 2019-nCoV have been confirmed in Taiwan, Thailand,  Japan and South Korea. The United States announced their first infection with 2019-nCoV detected in a traveler returning from Wuhan on January 21, 2020.

Coronaviruses are a large family of viruses, some causing illness in people and others that circulate among animals, including camels, cats and bats. Rarely, animal coronaviruses can evolve and infect people and then spread between people such as has been seen with MERS [ Middle East Respiratory Syndrome is viral respiratory illness that is new to humans. It was first reported in Saudi Arabia in 2012 and has since spread to several other countries, including the United States. Most people infected with MERS-CoV developed severe respiratory illness, including fever, cough, and shortness of breath. Many of them have died] and SARS [Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). SARS was first reported in Asia in February 2003. The illness spread to more than two dozen countries in North America, South America, Europe, and Asia before the SARS global outbreak of 2003 was contained. Since 2004, there have not been any known cases of SARS reported anywhere in the world]. When person-to-person spread has occurred with SARS and MERS, it is thought to have happened via respiratory droplets produced when an infected person coughs or sneezes, similar to how influenza and other respiratory pathogens spread. Spread of SARS and MERS between people has generally occurred between close contacts. Past MERS and SARS outbreaks have been complex, requiring comprehensive public health responses.

Early on, many of the patients in the outbreak in Wuhan, China reportedly had some link to a large seafood and animal market, suggesting animal-to-person spread. However, a growing number of patients reportedly have not had exposure to animal markets, suggesting person-to-person spread is occurring. At this time, it’s unclear how easily or sustainably this virus is spreading between people.

Both MERS and SARS have been known to cause severe illness in people. The situation with regard to 2019-nCoV is still unclear. While severe illness, including illness resulting in a number of deaths has been reported in China, other patients have had milder illness and been discharged.

It’s not clear yet how easily 2019-nCoV spreads from person-to-person. It’s important to know this in order to better assess the risk posed by this virus. While CDC considers this is a serious public health concern, based on current information, the immediate health risk from 2019-nCoV to the general American public is considered low at this time.

More cases are likely to be identified in the coming days, including possibly more cases in the United States. Given what has occurred previously with MERS and SARS, it’s likely that some person-to-person spread will continue to occur.

Notes: the above information was compiled on 23 of January 2020, from various sources, and primarily from the CDC; although I usually report scientific data from peer-reviewed papers, I felt this need be reported given a lot of my patients travel to China for business. Bisher Akil, MD