Under the electron microscope, a coronavirus may resemble a spiny sea urchin or appear crownlike, (the shape from which this family of pathogens takes its name). Previously recognized as the second leading cause of the common cold in humans and for economically important diseases in many domesticated animals, a new disease form abruptly emerged as a major public health concern in 2002, when the SARS coronavirus (CoV) surfaced in Asia.
