title: Household-level risk factors for secondary influenza-like illness in a rural area of Bangladesh.
abstract: To describe household-level risk factors for secondary influenza-like illness (ILI), an important public health concern in the low-income population of Bangladesh.
  
  
  
  Secondary analysis of control participants in a randomised controlled trial evaluating the effect of handwashing to prevent household ILI transmission. We recruited index-case patients with ILI - fever (<5 years); fever, cough or sore throat (≥5 years) - from health facilities, collected information on household factors and conducted syndromic surveillance among household contacts for 10 days after resolution of index-case patients' symptoms. We evaluated the associations between household factors at baseline and secondary ILI among household contacts using negative binomial regression, accounting for clustering by household.
  
  
  
  Our sample was 1491 household contacts of 184 index-case patients. Seventy-one percentage reported that smoking occurred in their home, 27% shared a latrine with one other household and 36% shared a latrine with >1 other household. A total of 114 household contacts (7.6%) had symptoms of ILI during follow-up. Smoking in the home (RRadj1.9, 95% CI: 1.2, 3.0) and sharing a latrine with one household (RRadj2.1, 95% CI: 1.2, 3.6) or >1 household (RRadj3.1, 95% CI: 1.8-5.2) were independently associated with increased risk of secondary ILI.
  
  
  
  Tobacco use in homes could increase respiratory illness in Bangladesh. The mechanism between use of shared latrines and household ILI transmission is not clear. It is possible that respiratory pathogens could be transmitted through faecal contact or contaminated fomites in shared latrines.
authors.affiliation: School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.|Richard M. Fairbanks School of Public Health, Indiana University, Indianapolis, IN, USA.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Weaver
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Kaniz
authors.initials: K
authors.lastname: Khatun-E-Jannat
authors.affiliation: School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Cercone
authors.affiliation: School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Krytus
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Badrul Munir
authors.initials: BM
authors.lastname: Sohel
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Makhdum
authors.initials: M
authors.lastname: Ahmed
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.
authors.forename: Mustafizur
authors.initials: M
authors.lastname: Rahman
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Azziz-Baumgartner
authors.affiliation: School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.
authors.forename: Jihnhee
authors.initials: J
authors.lastname: Yu
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Alicia M
authors.initials: AM
authors.lastname: Fry
authors.affiliation: International Centre for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.|Stanford University, Stanford, CA, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Luby
authors.affiliation: School of Public Health and Health Professions, University at Buffalo, Buffalo, NY, USA.
authors.forename: Pavani K
authors.initials: PK
authors.lastname: Ram
mesh_terms: D000293:Adolescent; D000328:Adult; D001459:Bangladesh / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D018562:Disease Transmission, Infectious / Q000517:prevention & control*; D005191:Family Characteristics; D005260:Female; D006235:Hand Disinfection; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012424:Rural Population; D016896:Treatment Outcome; D055815:Young Adult
keywords: Bangladesh; air pollution; environmental tobacco smoke; influenza; respiratory infections; sanitation