A newly identified coronavirus, which was first detected in Wuhan City, Hubei Province, China in late 2019, has begun to sicken people in China and other countries including the United States. Coronaviruses are a large family of viruses named for the crown-like shape of spikes on their surface. Seven coronaviruses including the newly identified virus, SARS, and MERS, are known to infect humans, primarily causing respiratory illnesses. Other coronaviruses circulate among animals, and rarely do animal coronaviruses evolve to be able to infect people. In the case of the newly identified coronavirus in China, health authorities suspect a large seafood and animal market was the origin of the outbreak, which suggests that at least initially there was animal-to-person transmission. However, a growing number of patients reportedly have not had exposure to animal markets, indicating person-to-person transmission. At this time, the CDC reports that it is unknown how easily or sustainably this virus is spreading between people.
Why worry? Outbreaks of new virus infections among human populations are always of public health concern. At the outset of an outbreak, much is unknown and remains to be discovered. How many people will be infected? How quickly will the outbreak spread? How sick will infected people become? Will there be deaths associated with the infection? Many answers to these questions depend on characteristics of the virus, and many will depend on and the medical or public health interventions available to control the impact of the virus (for example, vaccine or treatment medications).
As of January 24, the CDC and other international health authorities are continuing to monitor the situation and updates are likely as more information is collected.