Examining the Interrelationships of Child Infections, Growth, And Development towards an Integrated Intervention Agenda in Low and Middle-Income Countries

Abstract

Children in low- and middle-income countries (LMICs) face multiple social, economic, and environmental challenges that increase their risk of mortality, morbidities, poor growth, and suboptimal development outcomes. Considering the shared risk factors as well as the inter-relationships between child infectious disease morbidities, growth, and development, integrated interventions may be more effective in improving child well-being in resource-limited settings. However, critical evidence gaps remain in designing and delivering such interventions. First, a better understanding of the relationship between common infections and child development is needed. Second, while nutrition is identified as a critical link between child survival, growth and development, there is limited evidence on mediators that could be targeted to potentially maximize benefits across multiple domains. For example, diet and care may mediate the effects of parenting interventions on childhood infections, an area that has not been previously explored Finally, little is known about whether early child development interventions can also affect broader outcomes beyond the primary focus, such as child growth and infectious disease morbidity. To address these gaps, the overarching research question answered in this thesis was “How is early childhood infectious disease morbidity exposure associated with child development, and can the analysis of early childhood intervention effects on broader outcomes beyond the primary focus help inform integrated approaches for reducing child infectious disease morbidity and improving child growth and development?” Using longitudinal cohort data from a sequential randomized controlled trial in rural Niger, Paper 1 found negative relationships between common child infectious disease morbidities and development outcomes in the first two years of life. Paper 2 used data from a four-arm factorial-designed cluster-randomized controlled trial of a home-based responsive stimulation and nutrition intervention in the first 1000 days of life integrated into an existing community health worker program in rural Pakistan. Paper 2 showed that responsive stimulation intervention reduced the rates of common childhood infections while a nutrition intervention including iron-containing MNP increased the risk of fever among children under two years of age. Using data from a stepped wedge cluster-randomized controlled trial conducted in rural Pakistan, Paper 3 found that a center-based ECCE intervention without any nutrition input positively affected child linear growth while negatively affected weight-based anthropometric indicators among children 4.5 to 5.5 years of age. Collectively, these findings inform the need for integrated approaches for child infectious disease morbidity, growth, and development in the first and next 1000 days of life.