Cystic fibrosis in South Africa: spectrum of disease and determinants of outcome

Marco Zampoli; Janine Verstraete; Marlize Frauendorf; Reshma Kassanjee; Lesley Workman; Brenda M Morrow; Heather J Zar

doi:10.1183/23120541.00856-2020

Cystic fibrosis in South Africa: spectrum of disease and determinants of outcome

ERJ Open Res. 2021 Aug 2;7(3):00856-2020. doi: 10.1183/23120541.00856-2020. eCollection 2021 Jul.

Authors

Marco Zampoli^{1

2}, Janine Verstraete¹, Marlize Frauendorf³, Reshma Kassanjee⁴, Lesley Workman¹, Brenda M Morrow¹, Heather J Zar^{1

2}

Affiliations

¹ Dept of Paediatrics and Child Health, University of Cape Town, Cape Town, South Africa.
² South African MRC Unit for Child and Adolescent Health, University of Cape Town, Cape Town, South Africa.
³ Milpark Netcare Hospital, Johannesburg, South Africa.
⁴ Centre for Infectious Disease Epidemiology and Research, School of Public Health and Family Medicine, University of Cape Town, Cape Town, South Africa.

Abstract

Introduction: Little is known about cystic fibrosis (CF) in low- to middle-income settings. This study aimed to describe the spectrum and outcomes of CF in South Africa (SA) from the recently established SA CF registry (SACFR).

Methods: Demographic, diagnosis and clinical data were extracted from the SACFR. Cross-sectional univariable and multivariable regression analysis of best forced expiratory volume in 1 s (FEV₁; age≥6 years) and nutrition (all ages) in 2018 was conducted to investigate factors associated with severe lung disease (SLD; FEV₁ ≤3.0 z-score) and undernutrition.

Results: By December 2018, ancestry of 447 individuals included in the SACFR was Caucasian (315; 70%), mixed (87; 19%) and black African (41; 9%). Median diagnosis age was 7.6 months (IQR 2.7-37.1). Genotype was p.Phe508del homozygous (220; 49%); p.Phe508del heterozygous (144; 32%) and neither p.Phe508del or unknown Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) variant in 83 (19%); the second most frequent CFTR variant was 3120+1G>A, common in black Africans. Median age of patients in 2018 was 14.7 years (IQR 7.4-24.4). SLD was independently associated with chronic methicillin-resistant Staphylococcus aureus (MRSA) (adjusted odds ratio( aOR) 16.75; 95% CI 1.74-161.50), undernutrition (aOR 5.20; 95% CI 2.23-12.13) and age (aOR 2.23 per 10 years; 95% CI 1.50-3.31). Undernutrition was associated in univariable analysis with low weight at diagnosis, non-Caucasian ancestry, chronic P. aeruginosa infection and lower socioeconomic status.

Conclusion: Interventions targeting MRSA infection and nutrition are needed to improve CF outcomes in SA. Most people with CF in SA are eligible for highly effective CFTR modulator therapy.