Coronavirus is a bunch of viruses that cause diseases in mammals, including humans, and birds. In humans, the virus causes respiratory infections which are typically mild but, in rare cases, are often lethal. In cows and pigs, they will cause diarrhea, while in chickens it can cause an upper respiratory illness.

            Almost 20 years ago, an endemic appeared in wildlife markets in southern China, and it was unlike any the planet had seen. It was winter 2003, and sufferers complained of fever, chills, headache, and dry coughs-all symptoms you may expect during cold and flu season. But this condition would progress into a lethal variety of pneumonia, one that left honeycomb-shaped holes in people’s lungs and generated severe respiratory failure in a very quarter of patients. While most infections only spread to a few additional people, a number of the afflicted became “superspreaders”—patients who unwittingly transmitted the disease to dozens at a time.

By the time the epidemic of the severe acute respiratory syndrome (SARS) ended seven months later, over 8,000 cases and 800 deaths stretched across 32 countries. That’s why international officials are now concerned over a replacement, SARS-related virus that has emerged in central China. The disease has spread to major cities like Beijing, Shanghai, and Shenzhen—as well as neighboring Taiwan, Thailand, Japan, and South Korea—in just three weeks. On Tuesday, the Centers for Disease Control and Prevention (CDC) reported the primary U.S.“Human-to-human spread has been confirmed [but] how easily or sustainably this virus is spreading remains unknown,” Nancy Messonnier, director of the National Center for Immunization and Respiratory Diseases at the CDC, said in a very group discussion where she announced the event of a rapid genetic test for the Wuhan virus.“Right now we are testing for this virus at CDC, but within the coming weeks we anticipate sharing these tests with domestic and international partners.”