Friday, February 5, 2021

Summary

This blog by Musa Kana, a Nigerian perinatal and paediatric clinical epidemiologist, and Alliance for Accelerating Excellence in Science in Africa (AESA) grantee under the African Postdoctoral Training Initiative (APTI), discusses plans for a birth cohort study in Nigeria to inform preventive strategies for stunting in Africa, including consideration of a social-ecological model.

Why we need infant development birth cohort/group study

I first conceived the idea of developing a population surveillance system for public health research during a visit to the Medical Research Council (MRC) facilities in The Gambia in 2007. The research infrastructure we toured included the field sites and laboratory resources that support the conduct of basic scientific, clinical and epidemiological studies for several decades. My PhD research focused on investigating the growth and development of second-generation migrant children in Portugal using data from the Generation XXI Birth Cohort Study and 20 years data of the Portuguese national birth registry. I then began planning a longitudinal birth cohort study to learn about the developmental origins and aetiology (the cause, set of causes, or manner of causation of a disease or condition) of stunting in Nigeria. I led a pilot study (2017-2019) that demonstrated the feasibility of complete and consistent data collection for a longitudinal study, to be called the Kaduna Infant Development (KID) Birth Cohort Study. I was selected to be part of the inaugural cohort of the African Postdoctoral Training Initiative (APTI) Fellowship in 2018. My current work on characterizing the environmental exposures associated with stunting in Africa and planning for the KID Birth Cohort Study’s being conducted under the supervision of Dr Stephanie J. London at the US National Institute of Environmental Health Sciences. I am also acquiring the knowledge and skillset required to study the causal mechanisms of stunting, including epigenetic biomarkers (chemical changes to DNA) resulting from an adverse environment during critical stages of foetal and child development. Epigenetics further explains how early experiences can have lifelong impacts.

Childhood stunting: A global concern

Stunting of linear growth is the failure of a child to achieve genetically determined growth potential. Africa contributes to one-third of the global burden of childhood stunting. Stunting predominantly occurs in the first 1000 days of life and often begins during pregnancy. It results in suboptimal cognitive and motor development, increased risk of childhood diseases and death, and adverse health outcomes in adulthood. Nutritional interventions have not shown clear benefits on stunting occurrence. Environmental exposures are thought to contribute to stunting, but evidence regarding the specific exposures remains inconclusive. The occurrence of stunting in developing countries including Nigeria has not significantly declined in the last 30 years, indicating the need for investigation on other causal factors to inform more effective population-level interventions.

Understanding stunting in urban cities through a social and environmental model  

Evidence indicates that different environmental settings require different interventions to prevent stunting. Prospective birth cohort/group studies will reveal the timing of exposures during prenatal and postnatal life and help understand causal relationships associated with stunting, thus informing interventions to prevent stunting and its consequences. Moreover, a social-ecological model integrating individual and environmental risk factors is vital to investigating the potential mixed effects that lead to stunting of children, and to develop an ecological framework to identify and target intervention strategies based on the environment. Urban residence has been identified as a risk factor for intrauterine and postnatal malnutrition in Africa, the continent with the highest urbanization rate in the world, which is undergoing epidemiologic, nutritional, and economic transitions. But currently, many longitudinal data collection systems (Health and Demographic Surveillance Sites) in Africa are in rural areas with relatively similar demographic characteristics. These study populations are not suitable to investigate the complex interaction of socio-demographic, economic and environmental factors found in childhood stunting in cities. Therefore, I plan to conduct a prospective birth cohort study in an urban community in Northern Nigeria using low-cost approaches and incorporating a social-ecological model to investigate the risk factors and causal pathways associated with high occurrence of stunting in this setting.    

Building on a pilot study

The APTI fellowship has provided me with intensive training to plan and implement the birth cohort study. I have also connected with potential collaborators and investigators who have implemented similar studies in low- and middle-income countries, which generally lack resources for the cohort studies required to investigate causal factors and to develop preventive strategies. To enable future prospective studies, I led a team that designed, tested and piloted the Child Electronic Growth Monitoring System (CEGROMS) using a readily available electronic data capture platform. The system can be used for research and surveillance of individual‐level risk factors to guide public health response and has the potential to identify sensitive periods during early childhood growth and development to improve screening and institute preventive interventions. CEGROMS could also be efficiently and effectively scaled‐up to national levels.  

When the KID Birth Cohort Study is implemented in Nigeria, more extensive data on prenatal and early childhood exposures will be collected, including neighbourhood, household, maternal, paternal and infant variables. We hope that the information will inform public health interventions in Africa.

Footnotes

Growth Monitoring System (CEGROMS) using a readily available electronic data capture platform (https://pubmed.ncbi.nlm.nih.gov/32083347/).

About Musa Kana

Musa Kana is a Nigerian perinatal and paediatric clinical epidemiologist and African Postdoctoral Training Initiative (APTI) Fellow based at the United States National Institute of Environmental Health Sciences (NIEHS) and Federal University Lafia in Nigeria. APTI is implemented through the Alliance for Accelerating Excellence in Science in Africa (AESA), a funding, agenda setting and programme management platform of the African Academy of Sciences (AAS) and the African Union Development Agency (AUDA-NEPAD) supported by the U.S. National Institutes of Health (NIH) and the Bill & Melinda Gates Foundation. APTI trains African researchers in global health and develops their skills in clinical and translational research.