By analyzing ancient DNA, scientists determined when, where and how our ancestors got sick from infectious diseases.

Several dozen beaches were closed across Massachusetts on Saturday. There were 42 beaches closed in total, according to the ...

Eastern Ontario is at the epicentre of a tick population boom, and with it, health officials are reporting the highest levels ...

A contagious new COVID-19 variant called NB.1.8.1, aka "Nimbus," is now dominant in the United States, CDC data show. What to know about symptoms and vaccines.