Risk factors for tuberculosis in older children and adolescents: a matched case-control study in Recife, Brazil.

Hilary Stevens,Laura C Rodrigues,Ricardo Aa Ximenes,Odimariles Ms Dantas

doi:10.1186/s12982-014-0020-5

Abstract

BackgroundTuberculosis is a major disease worldwide and most research focus on risk factors for adults, although there is a marked adolescent peak in incidence. The objective of this study was to identify risk factors for tuberculosis in children aged 7 to 19.MethodsA case control study matched by age with 169 cases and 477 controls. The study population consisted of adolescents and older children from Recife, Brazil. Cases were individuals diagnosed with tuberculosis in the control programme and controls were selected in the neighborhood of cases. Conditional logistic regression was used to identify risk factors.ResultsCigarette smoking increased by 50% the risk of tuberculosis but that this was not statistically significant (OR = 1.6). Other risk factors were sleeping in the same house as a case of tuberculosis (OR = 31.6), living in a house with no piped water (OR = 7.7) (probably as a proxy for bad living conditions), illiteracy (OR = 3.7) and male sex (OR = 1.8). The increase in risk with living in houses with no piped water was much more marked in males. The proportion of cases of tuberculosis attributed to contact with someone with TB was 38% and to illiteracy, lack of piped water and smoking, 20%.ConclusionHousehold contact with tuberculosis, social factors and male sex play the biggest role in determining risk of TB disease among children and adolescents in the study. We recommend further research on the relationship of cigarette smoking on tuberculosis in adolescents, and on whether the sex differentials are more marked in bad living conditions. Separate studies should be conducted in older children and in adolescents.

Highlights

Tuberculosis is a major disease worldwide and most research focus on risk factors for adults, there is a marked adolescent peak in incidence
We report on the analysis of social factors for tuberculosis, using the same cases and control
Other factors statistically significantly associated with tuberculosis were male sex (OR = 1.82 95% CI 1.28, 2.60), cigarette smoking (OR = 2.66 95% CI 1.28, 5.52) and relationship to head of household (OR = 2.64 95% CI 1.57, 4.42), illiteracy (OR = 4.42 95% CI 1.82, 10.76) and low income (OR = 3.94 95% CI 1.56, 9.97)

Summary

Introduction

Tuberculosis is a major disease worldwide and most research focus on risk factors for adults, there is a marked adolescent peak in incidence. The objective of this study was to identify risk factors for tuberculosis in children aged 7 to 19. Tuberculosis infection is transmitted from person to person; likelihood of transmission increases with close and sustained exposure to a person with active pulmonary disease [3]. Because not all infections lead to disease, risk factors can increase the risk of tuberculosis by increasing risk of acquiring infection or increasing risk of developing clinical disease. It is harder to study separately risk of developing disease once infection is acquired but co-infection with HIV and with parasites, low vitamin D [10], and smoking have been suggested [11,12,13], probably through suppression of the host immune response. Smoking increases susceptibility to TB through reducing ciliary activity and mucus production by goblet cells, the pulmonary system’s first

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