1 University of North Carolina Project Malawi, Lilongwe, Malawi; Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7593, USA; Global Program in Pediatric Respiratory Sciences, Eudowood Division of Pediatric Respiratory Sciences, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: nadia.hoekstra.23@gmail.com.
2 University of North Carolina Project Malawi, Lilongwe, Malawi; Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
3 University of North Carolina Project Malawi, Lilongwe, Malawi; Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC 27599-7593, USA.
4 Department of Paediatrics, Kamuzu Central Hospital, Ministry of Health, Lilongwe, Malawi.
5 Global Program in Pediatric Respiratory Sciences, Eudowood Division of Pediatric Respiratory Sciences, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Department of International Health, Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Johns Hopkins University School of Medicine, Baltimore, MD, USA.