Epidemiology and risk factors for pneumonia severity and mortality in Bangladeshi children <5 years of age before 10-valent pneumococcal conjugate vaccine introduction

Background: Pneumonia is the leading infectious cause of morbidity and mortality in young children in Bangladesh. We present the epidemiology of pneumonia in Bangladeshi children < 5 years before 10-valent pneumococcal conjugate vaccine introduction and investigate factors associated with disease severity and mortality. Methods: Children aged 2-59 months admitted to three Bangladeshi hospitals with pneumonia (i. e., cough or difficulty breathing and age-specific tachypnea without danger signs) or severe pneumonia (i. e., cough or difficulty breathing and = 1 danger signs) were included. Demographic, clinical, laboratory, and vaccine history data were collected. We assessed associations between characteristics and pneumonia severity and mortality using multivariable logistic regression. Results: Among 3639 Bangladeshi children with pneumonia, 61% had severe disease, and 2% died. Factors independently associated with severe pneumonia included ages 2-5 months (adjusted odds ratio [aOR] 1.60 [95% CI: 1. 26-2.01]) and 6-11 months (aOR 1.31 [1.10-1.56]) relative to 12-59 months, low weight for age (aOR 1.22 [1.04-1.42]), unsafe drinking water source (aOR 2.00 [1.50-2.69]), higher paternal education (aOR 1.34 [1.15-1.57]), higher maternal education (aOR 0.74 [0.64-0.87]), and being fully vaccinated for age with pentavalent vaccination (aOR 0.64 [0.51-0.82]). Increased risk of pneumonia mortality was associated with age < 12 months, low weight for age, unsafe drinking water source, lower paternal education, disease severity, and having = 1 co-morbid condition. Conclusions: Modifiable factors for severe pneumonia and mortality included low weight for age and access to safe drinking water. Improving vaccination status could decrease disease severity.