Science
24 December 2010 vol 330, issue 6012, pages 1717-1852
http://www.sciencemag.org/current.dtl

News of the Week: Infectious Disease
Polio Outbreak Breaks the Rules
Leslie Roberts

Summary
Polio is a horrendous disease, but it is seldom fatal—except now. An explosive outbreak in the Republic of Congo is writing another chapter in the book on how this ancient scourge behaves. The new outbreak tearing through this West African country has so far killed an estimated 42% of its victims, who, in another unusual twist, are mostly adult males between the ages of 15 and 25. Since it began in early October, the outbreak has paralyzed more than 476 people and killed at least 179, according to World Health Organization estimates from early December, making this one of the largest and deadliest polio outbreaks in recent history. And one of the most mystifying, too, polio experts say.