1. Department of Physiotherapy, University of the Witwatersrand, Johannesburg, Republic of South Africa
2. Wits-University of Queensland Critical Care Infection Collaboration Group, University of the Witwatersrand, Johannesburg, Republic of South Africa
3. Department of Medicine, Divisions of Critical Care and Pulmonology, Charlotte Maxeke Johannesburg Academic Hospital and University of the Witwatersrand, Johannesburg, Republic of South Africa