The Fever Year occured in the year 1P8 (16 AL). It was the first epidemic in Pernese history, caused by a crossover between Terran and Pernese bacteria. It killed nearly 4,000 people out of a colony of 9,000. Among its victims were most of the children under 4, almost all expectant or new mothers, and 9 out of every 10 medics, as well as Emily Boll.
To avoid panic, it was decided to ascribe the epidemic to a "mysterious" illness, and to tell the people that the vaccine they received was merely a pallative, and that only those with natural immunities had survived, to avoid causign worry of future outbreaks.