For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia. The worldwide outbreak has sickened more than 156,000 people and left more than 5,800 dead. The death toll in the United States is more than 50, while infections neared 3,000 across 49 states and the District of Columbia.