He says it is unclear how the 5,800 "coronavirus cases" were determined to be from the virus when the tests are inaccurate and, in many cases, the tests are not even done at all. Patients who die of something other than coronavirus can be "presumed" to have the virus if they were in proximity of someone who either had the virus or who also was presumed to have it. These are called presumptive cases.

Let's go to NBC News for the word on what's happening in Italy. March 8, 2020, "Coronavirus updates live: Million quarantined in Italy, as D.C. reports first case". (see also this from Wall Street Journal)

This NBC piece, as so many others do, mixes and matches reports. Millions quarantined there, first case here. The tactic is meant to build up details of an overwhelming cascade of "proof": the threat is real, the storm clouds have opened and the rain is falling.

NBC: "Italy's government has placed more than 16 million people — a quarter of the population — under lockdown, in a drastic bid to prevent the spread of coronavirus."