title: Household-level risk factors for influenza among young children in Dhaka, Bangladesh: a case-control study.
abstract: OBJECTIVE
  To identify household-level factors associated with influenza among young children in a crowded community in Dhaka, Bangladesh.
  
  
  METHODS
  We conducted a case-control study using existing active surveillance for respiratory illness. Cases were children aged 12-59 months with laboratory-confirmed influenza. Controls were children frequency-matched by age group with no respiratory illness in the prior 6 months. We interviewed caregivers and observed household handwashing behaviour. Soap consumption was estimated by summing weight differences of three bars of soap sequentially left in each household. We measured concentrations of airborne particulate matter <2.5 μg in diameter (PM2.5) in a subset of households. We used logistic regression to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI).
  
  
  RESULTS
  We enrolled 145 cases and 341 controls between March 2009 and April 2010. Case and control household members were observed to wash hands with similar frequency during a 5-h period (mean, 0.64 events vs. 0.63, P = 0.87), and similar daily soap consumption per capita (mean 2.92 grams vs. 2.93, P = 0.92). Case households were more likely than controls to have crowded (≥4 persons) sleeping areas (aOR = 1.67, CI: 1.06-2.63) and cross-ventilated cooking spaces (aOR = 1.75, CI: 1.16-2.63). Case and control households had similar median 24-h geometric mean PM2.5 concentrations in the cooking (69.2 vs. 69.6 μg/m(3), P = 0.45) and sleeping (65.4 vs. 67.4 μg/m(3), P = 0.19) spaces.
  
  
  CONCLUSIONS
  Handwashing with soap was practiced infrequently and was not associated with paediatric influenza in this community. Interventions aimed at crowded households may reduce influenza incidence in young children.
authors: Centers for Disease Control and Prevention, Atlanta, GA, USA; Howard University, Washington, DC, USA.
authors: Saumil
authors: S
authors: Doshi
authors: Benjamin J
authors: BJ
authors: Silk
authors: Dhiman
authors: D
authors: Dutt
authors: Moshtaq
authors: M
authors: Ahmed
authors: Adam L
authors: AL
authors: Cohen
authors: Thomas H
authors: TH
authors: Taylor
authors: W Abdullah
authors: WA
authors: Brooks
authors: Doli
authors: D
authors: Goswami
authors: Stephen P
authors: SP
authors: Luby
authors: Alicia M
authors: AM
authors: Fry
authors: Pavani K
authors: PK
authors: Ram
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D001459:Bangladesh / Q000453:epidemiology; D016022:Case-Control Studies; D002675:Child, Preschool; D003441:Crowding; D005260:Female; D006235:Hand Disinfection; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology* / Q000517:prevention & control* / Q000635:transmission; D008297:Male; D052638:Particulate Matter / Q000032:analysis*; D011159:Population Surveillance; D011203:Poverty; D012307:Risk Factors; D012915:Soaps / Q000600:supply & distribution*; D011795:Surveys and Questionnaires
chemical_list: D052638:Particulate Matter; D012915:Soaps
keywords: Bangladesh; crowding; hacinamiento; handwashing; humain; human; humano; influenza; lavado de manos; lavage des mains; prevención y control; prevention and control; prévention et contrôle; surpeuplement