More good news:
All 3,711 passengers on the Diamond Princess cruise ship were tested, 712 tested positive, and of those, 331 (46 percent) have never shown outward symptoms, according to Japan’s health agency, which has also been cited by the CDC.
Bad news for unknowing transmission, but:
Non-symptomatic people can spread the disease, but, “we know that the virus is much more likely to spread from person to person if the infected one is showing symptoms,”