Leprosy reactions: the effect of gender and household contacts

Detalhes bibliográficos
Autor(a) principal: Mastrangelo,Giuseppe
Data de Publicação: 2011
Outros Autores: Silva Neto,Joaquim da, Silva,Gilberto Valentim da, Scoizzato,Luca, Fadda,Emanuela, Dallapicola,Monique, Folleto,Ana Luiza, Cegolon,Luca
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Memórias do Instituto Oswaldo Cruz
Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762011000100015
Resumo: Various host-related factors have been reported as relevant risk factors for leprosy reactions. To support a new hypothesis that an antigenic load in local tissues that is sufficient to trigger the immune response may come from an external supply of Mycobacterium leprae organisms, the prevalence of reactional leprosy was assessed against the number of household contacts. The number of contacts was ascertained at diagnosis in leprosy patients coming from an endemic area of Brazil. The prevalence of reactions (patients with reactions/total patients) was fitted by binomial regression and the risk difference (RD) was estimated with a semi-robust estimation of variance as a measure of effect. Five regression models were fitted. Model 1 included only the main exposure variable "number of household contacts"; model 2 included all four explanatory variables ("contacts", "fertile age", "number of skin lesions" and "bacillary index") that were found to be associated with the outcome upon univariate analysis; models 3-5 contained various combinations of three predictors. Male and female patients were analyzed separately. In females, household contacts were a significant predictor for leprosy reactions in model 1 [crude RD = 0.06; 95% confidence interval (CI) = 0.01; 0.12] and model 5 (RD = 0.05; CI = 0.02; 0.09), which included contacts, bacillary index and skin lesions as predictors. Other models were unsatisfactory because the joint presence of fertile age and bacillary index was a likely source of multicollinearity. No significant results were obtained for males. The likely interpretation of our findings might suggest that in female patients, leprosy reactions may be triggered by an external spreading of M. leprae by healthy carrier family members. The small number of observations is an obvious limitation of our study which requires larger confirmatory studies.
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spelling Leprosy reactions: the effect of gender and household contactsleprosyhousehold contactsreactionshealthy carrierschemoprophylaxisVarious host-related factors have been reported as relevant risk factors for leprosy reactions. To support a new hypothesis that an antigenic load in local tissues that is sufficient to trigger the immune response may come from an external supply of Mycobacterium leprae organisms, the prevalence of reactional leprosy was assessed against the number of household contacts. The number of contacts was ascertained at diagnosis in leprosy patients coming from an endemic area of Brazil. The prevalence of reactions (patients with reactions/total patients) was fitted by binomial regression and the risk difference (RD) was estimated with a semi-robust estimation of variance as a measure of effect. Five regression models were fitted. Model 1 included only the main exposure variable "number of household contacts"; model 2 included all four explanatory variables ("contacts", "fertile age", "number of skin lesions" and "bacillary index") that were found to be associated with the outcome upon univariate analysis; models 3-5 contained various combinations of three predictors. Male and female patients were analyzed separately. In females, household contacts were a significant predictor for leprosy reactions in model 1 [crude RD = 0.06; 95% confidence interval (CI) = 0.01; 0.12] and model 5 (RD = 0.05; CI = 0.02; 0.09), which included contacts, bacillary index and skin lesions as predictors. Other models were unsatisfactory because the joint presence of fertile age and bacillary index was a likely source of multicollinearity. No significant results were obtained for males. The likely interpretation of our findings might suggest that in female patients, leprosy reactions may be triggered by an external spreading of M. leprae by healthy carrier family members. The small number of observations is an obvious limitation of our study which requires larger confirmatory studies.Instituto Oswaldo Cruz, Ministério da Saúde2011-02-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762011000100015Memórias do Instituto Oswaldo Cruz v.106 n.1 2011reponame:Memórias do Instituto Oswaldo Cruzinstname:Fundação Oswaldo Cruzinstacron:FIOCRUZ10.1590/S0074-02762011000100015info:eu-repo/semantics/openAccessMastrangelo,GiuseppeSilva Neto,Joaquim daSilva,Gilberto Valentim daScoizzato,LucaFadda,EmanuelaDallapicola,MoniqueFolleto,Ana LuizaCegolon,Lucaeng2020-04-25T17:50:57Zhttp://www.scielo.br/oai/scielo-oai.php0074-02761678-8060opendoar:null2020-04-26 02:17:28.217Memórias do Instituto Oswaldo Cruz - Fundação Oswaldo Cruztrue
dc.title.none.fl_str_mv Leprosy reactions: the effect of gender and household contacts
title Leprosy reactions: the effect of gender and household contacts
spellingShingle Leprosy reactions: the effect of gender and household contacts
Mastrangelo,Giuseppe
leprosy
household contacts
reactions
healthy carriers
chemoprophylaxis
title_short Leprosy reactions: the effect of gender and household contacts
title_full Leprosy reactions: the effect of gender and household contacts
title_fullStr Leprosy reactions: the effect of gender and household contacts
title_full_unstemmed Leprosy reactions: the effect of gender and household contacts
title_sort Leprosy reactions: the effect of gender and household contacts
author Mastrangelo,Giuseppe
author_facet Mastrangelo,Giuseppe
Silva Neto,Joaquim da
Silva,Gilberto Valentim da
Scoizzato,Luca
Fadda,Emanuela
Dallapicola,Monique
Folleto,Ana Luiza
Cegolon,Luca
author_role author
author2 Silva Neto,Joaquim da
Silva,Gilberto Valentim da
Scoizzato,Luca
Fadda,Emanuela
Dallapicola,Monique
Folleto,Ana Luiza
Cegolon,Luca
author2_role author
author
author
author
author
author
author
dc.contributor.author.fl_str_mv Mastrangelo,Giuseppe
Silva Neto,Joaquim da
Silva,Gilberto Valentim da
Scoizzato,Luca
Fadda,Emanuela
Dallapicola,Monique
Folleto,Ana Luiza
Cegolon,Luca
dc.subject.por.fl_str_mv leprosy
household contacts
reactions
healthy carriers
chemoprophylaxis
topic leprosy
household contacts
reactions
healthy carriers
chemoprophylaxis
dc.description.none.fl_txt_mv Various host-related factors have been reported as relevant risk factors for leprosy reactions. To support a new hypothesis that an antigenic load in local tissues that is sufficient to trigger the immune response may come from an external supply of Mycobacterium leprae organisms, the prevalence of reactional leprosy was assessed against the number of household contacts. The number of contacts was ascertained at diagnosis in leprosy patients coming from an endemic area of Brazil. The prevalence of reactions (patients with reactions/total patients) was fitted by binomial regression and the risk difference (RD) was estimated with a semi-robust estimation of variance as a measure of effect. Five regression models were fitted. Model 1 included only the main exposure variable "number of household contacts"; model 2 included all four explanatory variables ("contacts", "fertile age", "number of skin lesions" and "bacillary index") that were found to be associated with the outcome upon univariate analysis; models 3-5 contained various combinations of three predictors. Male and female patients were analyzed separately. In females, household contacts were a significant predictor for leprosy reactions in model 1 [crude RD = 0.06; 95% confidence interval (CI) = 0.01; 0.12] and model 5 (RD = 0.05; CI = 0.02; 0.09), which included contacts, bacillary index and skin lesions as predictors. Other models were unsatisfactory because the joint presence of fertile age and bacillary index was a likely source of multicollinearity. No significant results were obtained for males. The likely interpretation of our findings might suggest that in female patients, leprosy reactions may be triggered by an external spreading of M. leprae by healthy carrier family members. The small number of observations is an obvious limitation of our study which requires larger confirmatory studies.
description Various host-related factors have been reported as relevant risk factors for leprosy reactions. To support a new hypothesis that an antigenic load in local tissues that is sufficient to trigger the immune response may come from an external supply of Mycobacterium leprae organisms, the prevalence of reactional leprosy was assessed against the number of household contacts. The number of contacts was ascertained at diagnosis in leprosy patients coming from an endemic area of Brazil. The prevalence of reactions (patients with reactions/total patients) was fitted by binomial regression and the risk difference (RD) was estimated with a semi-robust estimation of variance as a measure of effect. Five regression models were fitted. Model 1 included only the main exposure variable "number of household contacts"; model 2 included all four explanatory variables ("contacts", "fertile age", "number of skin lesions" and "bacillary index") that were found to be associated with the outcome upon univariate analysis; models 3-5 contained various combinations of three predictors. Male and female patients were analyzed separately. In females, household contacts were a significant predictor for leprosy reactions in model 1 [crude RD = 0.06; 95% confidence interval (CI) = 0.01; 0.12] and model 5 (RD = 0.05; CI = 0.02; 0.09), which included contacts, bacillary index and skin lesions as predictors. Other models were unsatisfactory because the joint presence of fertile age and bacillary index was a likely source of multicollinearity. No significant results were obtained for males. The likely interpretation of our findings might suggest that in female patients, leprosy reactions may be triggered by an external spreading of M. leprae by healthy carrier family members. The small number of observations is an obvious limitation of our study which requires larger confirmatory studies.
publishDate 2011
dc.date.none.fl_str_mv 2011-02-01
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762011000100015
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0074-02762011000100015
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.1590/S0074-02762011000100015
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv text/html
dc.publisher.none.fl_str_mv Instituto Oswaldo Cruz, Ministério da Saúde
publisher.none.fl_str_mv Instituto Oswaldo Cruz, Ministério da Saúde
dc.source.none.fl_str_mv Memórias do Instituto Oswaldo Cruz v.106 n.1 2011
reponame:Memórias do Instituto Oswaldo Cruz
instname:Fundação Oswaldo Cruz
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reponame_str Memórias do Instituto Oswaldo Cruz
collection Memórias do Instituto Oswaldo Cruz
instname_str Fundação Oswaldo Cruz
instacron_str FIOCRUZ
institution FIOCRUZ
repository.name.fl_str_mv Memórias do Instituto Oswaldo Cruz - Fundação Oswaldo Cruz
repository.mail.fl_str_mv
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