As a result of all of the uncertainty inherent in the available HIV data and the limitations of the methods used for estimating HIV prevalence, for countries with an estimated low HIV prevalence rate (< 0.1% of the adult population)), the actual prevalence can be up to several times higher or lower.  For countries with a moderate HIV prevalence estimate (> 0.1 and < 1%), the actual prevalence can vary from 1-2 folds higher or lower, and for high estimated HIV prevalence countries (> 1%), their actual prevalence can be double or half of the estimated prevalence.  With such wide variance in HIV prevalence estimates, it is unrealistic to attempt estimation of the annual number (i.e., incidence) of new HIV infections for any population or for the world.  Nevertheless, such “official” estimates of marked increases in annual HIV incidence continue to be widely disseminated by UNAIDS and most AIDS programs.