The identification of any new pathogen, such as the COVID-19 virus, is accompanied by many unknowns, particularly its ability to spread in the human population and its virulence.
Initial surveillance strategies focus primarily on the use of molecular testing (RT-PCR) to measure acute infection in patients with severe disease, as these are the individuals who seek and require health care. This may miss the fraction of mild or asymptomatic infections that do not require medical attention, and as such, the full spectrum of the disease is not known.
The answers to the questions below are based on our current understanding of the COVID-19 virus and the disease it causes. WHO will continue to update these answers as new information becomes available.
Kang
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