01914nas a2200349   4500000000100000008004100001260004700042653001500089653001000104653001600114653000900130653001100139653001000150653002100160653001100181653001100192653001100203653001200214653000900226653001600235653002500251653000900276653001600285100001400301700001500315700002100330245004700351300001000398490000700408520113500415022001401550       2012                            d  c2012 FebbBlackwell Publishing LtdaOxford10aAdolescent10aAdult10aAge Factors10aAged10aBrazil10aChild10aChild, Preschool10aFemale10aHumans10aInfant10aleprosy10aMale10aMiddle Aged10aPoisson Distribution10aRisk10aYoung Adult1 aPenna MLF1 aPedrosa VL1 aSantos Pereira E00aLeprosy decline in Amazonas State, Brazil.  a244-60 v173 a<p><b>OBJECTIVE: </b>To analyse the leprosy case detection rates in Amazonas State, Brazil, by age group from 1980 to 2009.</p><p><b>METHOD: </b>The historical data series of leprosy cases by age group from 1980 to 2009 were fitted as a function of time using Poisson regression models. Relative annual reduction in the detection rate (RAR) by age group was estimated as one minus the exponential of the estimated regression coefficient for time. To compare the regression coefficients, we used their 95% confidence interval.</p><p><b>RESULTS: </b>The relative annual reduction varied from 9% in the age group of 0-4 years to 1% in the age group of 60-69 years. There was a declining trend of the RAR in the younger age groups that disappeared after 29 years of age. The detection rate in people >29 years old declined very little over time, with no statistically significant difference between age groups.</p><p><b>CONCLUSION: </b>Our findings show a reduction in the infection risk in the last 30 years and a birth cohort effect: cohorts born in more recent years faced smaller risks of leprosy infection than older cohorts.</p>  a1365-3156