What we know — and don’t know — about a new virus causing pneumonia in China
A mysterious outbreak of pneumonia in central China has preliminarily been pegged to a new coronavirus, but the World Health Organization says there’s no need to panic. Chinese officials have reported little evidence so far of human-to-human transmission, the WHO says, making an epidemic less likely. Coronaviruses can cause a wide variety of illnesses, from a common cold to the more severe acute respiratory syndrome, or SARS. A global outbreak of SARS that began in China in 2003 killed 774 people and infected thousands more (SN: 3/26/03). A different coronavirus sparked another deadly outbreak in 2012, with the illness called Middle East respiratory syndrome, or MERS, killing more than 800 people (SN: 7/8/16). Both of those outbreaks began with the virus jumping from animals to humans, and accelerated by spreading among people. In December, reports emerged of mysterious pneumonia cases in the central Chinese city of Wuhan, with 59 cases confirmed as of January 5. Some patients were vendors at a seafood...