Efficient and timely virus testing is a crucial prerequisite for early identification, reporting, isolation, diagnosis and treatment. Testing casts direct impact on the effectiveness of epidemic prevention and control. WHO has called on all countries to ramp up testing programs. Dr. Tedros, Director-General of WHO, made it clear at the media briefing in Geneva on March 16, “We have a simple message for all countries: test, test, test. Test every suspected case.”

First, testing helps identify sources of infection and facilitates overall and targeted planning of epidemic prevention and control. Testing being one of the main means, identifying sources of infection is the precondition and basis of infectious disease prevention and control. China tested potential infectors to identify confirmed cases. On this basis, China adopted a series of measures including conducting targeted epidemiological investigation, tracing close contacts, as well as quarantining and testing close contacts. These have effectively prevented further spread of the epidemic.