Science and Medicine
The 1976 Legionnaires' disease outbreak, occurring in the late summer in Philadelphia, Pennsylvania, at an annual American Legion convention, was the first occasion in which a cluster of a particular type of pneumonia cases were determined to be caused by the Legionella pneumophila bacteria. Previous outbreaks were retroactively diagnosed as being most probably caused by Legionella bacteria.
HIV/AIDS in Asia.
Cryosurgery.
Text from Wikipedia; plate via Wikimedia Commons. Text CC BY-SA 4.0; plate freely licensed (see Commons). Source record. Images and catalogue data are reproduced from open-access collections.