The majority of the cases occurred north of the 38th parallel in the Yonchon-Chorwon-Kumhwa section of the front and the remainder in a belt along the 38th parallel,” wrote Carleton Gajdusek, an epidemiologist. “All evidence points toward infection from a common localized source over a brief period.

Nicholson Baker, Baseless- My Search for Sec…, loc. 648