Research adds to evidence showing how archaic species shaped modern humans.
Vaccination rates in some European countries are extremely low.
In the U.S., 12 to 19 million people get sick from waterborne infectious disease each year.
The world's first vaccine created in 1798 may not be what we've always thought it is.
The United States was the site of the first monkeypox outbreak outside Africa, in 2003.
Scientists have long thought that the tick and mosquito immune systems were the same. But their differences reveal a fascinating evolutionary legacy — and maybe a way to stop dangerous infections.
The CDC is attempting to help state health officials find the cause of the outbreak.
Health officials say they have not yet seen a case of local transmission in the U.S.
The risk for HIV transmission through blood transfusion is incredibly small.
It's rare to find infections this far north.
The mosquito-borne disease is taking hold as Yemen's health care system falls apart.
Health officials are tracking down airplane passengers who may have had direct contact with the woman.
Research on this parasite has the public believing every cat owner is at risk for psychiatric illness.
The World Health Organization predicts more cases in the country, where MERS has already claimed two lives.