The doctor leading the fight against Ebola in Sierra Leone is now being treated for the deadly virus.

Research suggests untouchable "viral reservoirs" form even before H.I.V. can be detected in the blood.

Stroke cases have declined, but men and African Americans still have higher rates.

The Ivory Coast has blocked refugees fleeing from Liberia amid fears for the virus' spread.

Ban Ki-moon, U.N. chief, says he will try to raise $2.2B to fight spread of the disease.

Employees at the National Institutes of Health have discovered forgotten vials of variola.

Researchers are working on a birth control chip that will last 16 years.

Research has identified a set of proteins in the blood that can predict the start of dementia with 87% accuracy.

The man was in his 40's and had been quarantined in the megacity.