Chi, Benjamin H., MD, MSc1; Mutale, Wilbroad, MBChB, PhD2; Winston, Jennifer, PhD1; Phiri, Winifreda, RN1; Price, Joan T., MD, MPH1; Mwiche, Angel, MBChB, MMed, MPH3; Ayles, Helen, MBBS, PhD4,5; Stringer, Jeffrey S. A., MD1