Factors Associated with Acute Respiratory Infection among Children Under 5 Years in India: Results from 2019 to 2021 National Family Health Survey.

Introduction: Acute respiratory infections (ARIs) remain the leading global cause of death in children under-five. Targeted initiatives are needed to address healthcare inequities and reduce under-five mortality, particularly in disproportionately impacted low- and middle- income countries. To inform initiatives and identify high-risk groups, this study explored regional risk factors for ARIs among Indian children. Material and Methods: Our retrospective, observational study utilized India's National Family Health Survey (NFHS-5). Bivariate and multivariable models were employed to investigate associations between respiratory infections and explanatory variables, including environmental factors, child characteristics, maternal characteristics, enabling factors, and household characteristics. Results: Of the 201,133 children under-five included in our sample, 2.85% [2.78-2.92%] experienced a recent respiratory infection. In multivariate analysis, children from northern and central regions had the highest odds of infection, while those from the southern region had the lowest. Healthcare accessibility, maternal smoking, caste, age (child), and birthweight were among additional variables associated with infections. Our study revealed significant regional differences in prevalence of acute respiratory infection symptoms. Notably, inability to access healthcare increased a child's risk of infection. Several states in southern India, which typically had lower ARI symptom rates, have adopted initiatives to strengthen public health infrastructure, including the WHO's Integrated Management of Neonatal and Childhood Illnesses program. Such initiatives could serve as models for broader health improvement efforts across regions. Furthermore, observed variability in disease burden suggests that with detailed and deliberate implementation of programs, advancements in under-five mortality due to ARI can be achieved.