Timeline of Reported Cases

Published on December 17, 2019 at 5:00 PM ET

People infected with the outbreak strains, by date of illness onset*

*n=30 for whom information was reported as of December 11, 2019. Some illness onset dates have been estimated from other reported information.

Illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported to the state health department and then to CDC. This can take several weeks.