(A) The number of poliomyelitis outbreaks reported for each country in Africa between 1 July 2004 and 31 December 2010. (B) The expected number of poliomyelitis outbreaks for each country in Africa based on the fit of the Poisson mixed effects model. (C) The temporal fit of the Poisson mixed effects model, where error bars show the 95% CIs, and the reported number of outbreaks for each 6-mo period.