Coronaviruses are a large family of viruses, some causing respiratory illness in people and others circulating among animals. Rarely, animal coronaviruses can evolve and infect people and then spread between people. Previous coronavirus outbreaks have included severe acute respiratory syndrome (SARS) and Middle East Respiratory Syndrome (MERS). The U.S. Centers for Disease Control and Prevention (CDC) believes the risk to the American public of becoming infected with this novel coronavirus is currently low. Because this is an emerging, rapidly evolving situation, the CDC will provide updated information as it becomes available, including any changes in the risk assessment.