Risk factors for hospital admission due to acute lower respiratory tract infection in Guarani indigenous children in southern Brazil: a population-based case-control study

Objective To assess risk factors associated with hospital admission due to acute lower respiratory tract infection (ALRTI) in indigenous Guarani children <5years of age in southern Brazil. Methods Population-based matched casecontrol study from May 2007 to June 2008 in 81 Guarani villages. Cases were defined as hospital admissions due to confirmed ALRTI. Two controls free from acute respiratory infection, matched according to age, sex and place of residence, were selected for each case at the time of the case's hospitalisation. Both cases and controls were recruited by a surveillance routine established for the study. Results The analysis was performed on 120 cases and 201 controls. The risk factors that remained significantly associated with hospitalisation due to ALRTI in the hierarchical multivariate conditional logistic regression were: low stable monthly per capita household income (<US$30.00=OR: 2.77, IC95%: 1.515.10; no income= OR: 1.88, IC95%: 1.023.47); large number of persons in the household (69= OR: 2.03, IC95%: 1.063.88; 1016= OR: 5.00, IC95%: 1.8113.86); indoor exposure to fumes from burning firewood used for cooking (OR: 3.08, IC95%: 1.396.84);low maternal age (OR: 2.77, IC95%: 1.425.39); and low birthweight (OR: 6.12, IC95%: 1.4426.13). Conclusion Acute respiratory infections are a major cause of morbidity and mortality among Guarani children. Our study provides the first evidence about their determinants in indigenous peoples in Brazil that can help to better understand the epidemiology of respiratory infections in indigenous children.