The World Health Organization has declared that an outbreak of Ebola in Central Africa is a public health emergency. Health ...

A new national wastewater map is offering a window into the spread of the highly contagious norovirus across the United States.

CNN is tracking what we know about the outbreak in maps and charts.

The virus's long incubation period is making it difficult for investigators to pinpoint where the infection occurred.

Learn more about the deadly 2026 Ebola outbreak, including how many cases there are so far, which countries are most affected, how this outbreak compares with others in severity and more.

NBC News is continuing to track confirmed measles cases across the United States, using Centers for Disease Control and ...

The virus circulated undetected for weeks. Heavy population movement in the area could make it spread farther.

Passengers and close contacts, some with symptoms, are being monitored until not contagious: From Santa Clara, California, to Nebraska, to Emory University in Atlanta.