Dödligt virus från Kina orsakar panik (SARS-CoV-2, COVID-19)

Notably, the full denominator remains unknown because asymptomatic cases or patients with very mild symptoms might not be tested and will not be identified. Such cases therefore cannot be included in the estimation of actual mortality rates, since actual estimates pertain to clinically apparent COVID-19 cases.

The Lancet

Enter the Diamond Princess cruise ship. Quarantined at sea off Japan after a passenger tested positive for SARS-CoV-2, the ship became a natural data lab where nearly everyone was tested and few cases of infection were missed..... Extrapolating those numbers to China, the team estimates that 1.1 percent of symptomatic cases there turned deadly. Considering asymptomatic cases drops that ratio to about 0.5 percent in China, the team calculates..... These ratios depend on available health care and public health measures..... some patients initially counted as asymptomatic may later develop symptoms, or even die. So the true fatality rate may be somewhat
higher, “0.6 or 0.7 [percent], but it’s still a good ratio.”

sciencenews.org

This data is unique, because due to the small self-contained population of a stranded cruise ship. Riou et al build a model from a series of assumptions about how the disease progresses. The assumptions are not wild guesses, they are based on measures made by the Chinese public health agency plus what we know from previous epidemics. Interestingly, they also make use of data from infections of passengers on a cruise ship. They put their models together and estimated a total fatality rate of about 1.6 per cent. That means they estimate that 1.6 per cent of the people infected will die, on average.

study, Riou et al

A panel of experts at the University of California, San Francisco, predicted that between 40 and 70% of Americans could become infected within the next 18 months, one internist attending the panel said.
Assuming a 1% mortality rate from the coronavirus, and 50% of the US population becoming infected, that means about 1.5 million Americans could die — that's if no drug is found effective and made available.

businessinsider