03168nas a2200409   4500000000100000008004100001260001600042653001500058653001000073653001000083653002100093653002000114653003700134653001100171653001100182653001100193653001200204653000900216653001600225653002500241653002000266653001600286100001200302700002000314700001400334700001300348700001200361700001200373700001200385245007200397856008000469300001000549490000600559050001600565520216300581022001402744       2011                            d  c2011 Mar 1510aAdolescent10aAdult10aChild10aChild, Preschool10aContact Tracing10aDisease Transmission, Infectious10aFemale10aHumans10aInfant10aleprosy10aMale10aMiddle Aged10aMycobacterium leprae10aRisk Assessment10aYoung Adult1 aSales A1 aPonce de Leon A1 aDuppre NC1 aHacker M1 aNery JA1 aSarno E1 aPenna M00aLeprosy among patient contacts: a multilevel study of risk factors.  uhttp://www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd.0001013  ae10130 v5  aSALES 2011a3 a<p><b>BACKGROUND: </b>This study aimed to evaluate the risk factors associated with developing leprosy among the contacts of newly-diagnosed leprosy patients.</p><p><b>METHODOLOGY/PRINCIPAL FINDINGS: </b>A total of 6,158 contacts and 1,201 leprosy patients of the cohort who were diagnosed and treated at the Leprosy Laboratory of Fiocruz from 1987 to 2007 were included. The contact variables analyzed were sex; age; educational and income levels; blood relationship, if any, to the index case; household or non-household relationship; length of time of close association with the index case; receipt of bacillus Calmette-Guérin (BGG) vaccine and presence of BCG scar. Index cases variables included sex, age, educational level, family size, bacillary load, and disability grade. Multilevel logistic regression with random intercept was applied. Among the co-prevalent cases, the leprosy-related variables that remained associated with leprosy included type of household contact, [odds ratio (OR) = 1.33, 95% confidence interval (CI): 1.02, 1.73] and consanguinity with the index case, (OR = 1.89, 95% CI: 1.42-2.51). With respect to the index case variables, the factors associated with leprosy among contacts included up to 4 years of schooling and 4 to 10 years of schooling (OR = 2.72, 95% CI: 1.54-4.79 and 2.40, 95% CI: 1.30-4.42, respectively) and bacillary load, which increased the chance of leprosy among multibacillary contacts for those with a bacillary index of one to three and greater than three (OR = 1.79, 95% CI: 1.19-2.17 and OR: 4.07-95% CI: 2.73, 6.09), respectively. Among incident cases, household exposure was associated with leprosy (OR = 1.96, 95% CI: 1.29-2.98), compared with non-household exposure. Among the index case risk factors, an elevated bacillary load was the only variable associated with leprosy in the contacts.</p><p><b>CONCLUSIONS/SIGNIFICANCE: </b>Biological and social factors appear to be associated with leprosy among co-prevalent cases, whereas the factors related to the infectious load and proximity with the index case were associated with leprosy that appeared in the incident cases during follow-up.</p>  a1935-2735