The Child Ecosystem and Childhood Pulmonary Tuberculosis: A South African Perspective
Teresa DeAtley,1 Lesley Workman,2Grant Theron,3 Sabine Bélard, 2,4,5Margaretha Prins,2 Lindy Bateman,2Martin P Grobusch,4,6 Keertan Dheda,11,12 Mark P Nicol,8 Katherine Sorsdahl,9 Caroline Kuo,1,10 Dan J Stein,10 Heather J Zar2
  1. Brown University School of Public Health, Department of Behavioral and Social Sciences Brown University School of Public Health, 121 S Main St, Providence, Rhode Island 02903, USA
  2. Department of Paediatrics and Child Health, Red Cross War Memorial Children’s Hospital, and SAMRC unit on Child and Adolescent Health, University of Cape Town; Cape Town, South Africa.
  3. DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
  4. Center of Tropical Medicine and Travel Medicine, Amsterdam University Medical Centers, location AMC, University of Amsterdam, Amsterdam, The Netherlands.
  5. Department of Paediatric Pneumology and Immunology, Charité - Universitätsmedizin, Berlin, Germany.
  6. Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
  7. Lung Infection and Immunity Unit, Division of Pulmonology and University of Cape Town Lung Institute, Department of Medicine, University of Cape Town, Cape Town, South Africa
  8. Division of Infection and Immunity, School of Biomedical Sciences, University of Western Australia, Perth, Australia and Division of Medical Microbiology, University of Cape Town and National Health Laboratory Services, Cape Town, South Africa.
  9. Alan J Flisher Centre for Public Mental Health, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa.
  10. Department of Psychiatry and Neuroscience Institute, and SA MRC unit on Risk and Resilience University of Cape Town, South Africa
  11. Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa.
  12. Faculty of Infectious and Tropical Diseases, Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK.
Keywords: TB risk factors, conceptual hierarchical frameworks
Corresponding Author: Professor Heather J. Zarᶧ
Department of Paediatrics and Child Health,
5th floor ICH Building,
Red Cross War Memorial Children’s Hospital
Cape Town
South Africa
Tel: 2721-658-5324
Acknowledgements
We gratefully acknowledge the contributions of the NHLS diagnostic microbiology laboratory at Groote Schuur Hospital; the study, laboratory and clinical staff at Red Cross Children’s Hospital and the Division of Medical Microbiology, and the children and their caregivers.
Funding The study was funded by the National Institute of Health, USA (1R01HD058971-01), the Medical Research Council of South Africa, the National Research Foundation (NRF) South Africa and the EDCTP (TB-NEAT; IP.2009.32040.009). Prof Zar and Stein are supported by the Medical Research Foundation of South Africa. Prof Dheda acknowledges funding from the SA MRC (RFA-EMU-02-2017), EDCTP (TMA-2015SF-1043, TMA-1051-TESAII, TMA-CDF2015), UK Medical Research Council (MR/S03563X/1) and the Wellcome Trust (MR/S027777/1).
Ethical Standards
The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. Written, informed consent was obtained from a parent or legal guardian and assent from children older than seven years. The study was approved by the Human Research Ethics Committee of the Faculty of Health Sciences, University of Cape Town.
Abstract
Introduction
This study investigates drivers of childhood pulmonary tuberculosis (PTB) using a childhood ecosystem approach in South Africa. An ecosystem approach towards identifying risk factors for PTB may identify new directions for intervention.
Methods
Data were collected as part of a prospective cohort study of children presenting at a primary care facility or tertiary hospital with suspected TB. Characterization of the childhood ecosystem included proximal, medial and distal determinants. Proximal determinants included child characteristics that could impact PTB outcomes. Medial determinants included relational factors such as caregiver health that might impact interactions with the child. Distal determinants included macro-level determinants of disease such as socioeconomic status and food insecurity. Children started on TB treatment were followed for up to 6 months. Multivariate regression models tested independent associations between factors associated with PTB in children.
Results
Of 1,738 children enrolled in the study, 242 (20%) of children had confirmed PTB, 756 (63%) were started on TB treatment, and 444 (37%) had respiratory conditions other than TB. In univariate analyses, childhood malnutrition and caregiver smoking were associated with treated or confirmed PTB. In multivariate analyses, proximal factors such as male gender and hospitalization and low socio-economic status as a distal factor were associated with PTB.
Conclusions
Interventions may need to target subgroups of children and families at elevated risk for PTB. Screening for risk factors such caregiver health may guide targeting, and provision of social protection programs to bolster economic security may be important interventions for attenuating childhood exposure to risk factors.