title: Anti-PGL-I seroepidemiology in leprosy cases: household contacts and school children from a hyperendemic municipality of the Brazilian Amazon.
abstract: OBJECTIVE
  We investigated the prevalence of antibodies against PGL-I in people affected by leprosy (PAL) who were diagnosed and treated between 2004 and 2010, their household contacts (HC) and school children (SC) from a hyperendemic municipality in the Brazilian Amazon, and determined the prevalence of previously undiagnosed leprosy (PPUL) among both the HC and SC.
  
  
  METHODS
  We conducted a cross-sectional study involving 87 PAL, 302 HC and 188 SC. The subjects were clinically assessed, and their levels of anti-PGL-I antibodies were determined by ELISA. The subjects were also interviewed to determine their demographic and socio-economic characteristics.
  
  
  RESULTS
  For PAL, a mean of 44 (SD = 21.8) months had passed since their initial diagnosis, and 34 (39%) of them remained seropositive. The level of anti-PGL-I antibodies was significantly higher in multibacillary (MB) than in paucibacillary (PB) cases (P < 0.05). Thirty-nine percent of HC were positive for anti-PGL-I, and we detected eight (2.6%) new cases among these individuals. One hundred and twenty-five SC (66.5%) were seropositive, and we detected nine (4.8%) new cases of leprosy (eight PB and one MB) in this group. When we visited the homes of SC affected by leprosy, 31 contacts were clinically examined, and three (10%) new cases were detected (one PB and two MB). The mean age of students with leprosy was 14.1 years (SD = 2.5; min = 10, max = 18).
  
  
  CONCLUSIONS
  The seroepidemiology of anti-PGL-I and the PPUL among both HC and SC suggests that there are many active foci of infection and that Mycobacterium leprae is circulating among this population.
authors.affiliation: Dermato-Immunology Laboratory UEPA/UFPA/Marcello Candia, Marituba, Pará, Brazil.
authors.forename: Josafá Gonçalves
authors.initials: JG
authors.lastname: Barreto
authors.forename: Layana De Souza
authors.initials: Lde S
authors.lastname: Guimarães
authors.forename: Márcia Regina Neves
authors.initials: MR
authors.lastname: Leão
authors.forename: Denis Vieira Gomes
authors.initials: DV
authors.lastname: Ferreira
authors.forename: Rosanna Alves De Araújo
authors.initials: RA
authors.lastname: Lima
authors.forename: Claudio Guedes
authors.initials: CG
authors.lastname: Salgado
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D005191:Family Characteristics; D005260:Female; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007918:Leprosy / Q000175:diagnosis* / Q000453:epidemiology* / Q000276:immunology / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000276:immunology / Q000302:isolation & purification*; D015995:Prevalence; D016036:Seroepidemiologic Studies; D013334:Students; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006017:Glycolipids; C045169:phenolic glycolipid I, Mycobacterium leprae