What is coronavirus testing? Coronavirus testing looks for signs of a coronavirus infection in nasal secretions, blood, or other body fluids. Coronaviruses are types of viruses that infect the respiratory system. They are found in both animals and people. Coronavirus infections in people are common throughout the world. They don't usually cause serious illness. Sometimes a coronavirus that infects animals will change and turn into a new coronavirus that can infect people. These coronaviruses can be more serious and sometimes lead to pneumonia . Pneumonia is a life-threatening condition in which fluid builds up in the lungs. Three of these new coronaviruses have been discovered in recent years: SARS (severe acute respiratory syndrome), a serious and sometimes fatal respiratory illness. It was first discovered in China in 2002 and spread around the world. An international effort helped quickly contain the spread of disease. There have been no new cases reported anywh...