Executive summaryInitial recommendations for protecting health care workers (HCWs) against COVID-19 were based on an early and incomplete understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission; namely, that it occurred mainly via large respiratory droplets (>10 µm) that were inhaled into the nasopharynx, directly inoculated onto mucous membranes, deposited on the skin and transferred by direct contact, or transferred indirectly by infected fomites. There is now substantial evidence to show that transmission by aerosol (particles <10 µm that can remain suspended for hours before being inhaled) is likely the predominant mode, with skin- and fomite-based transmission thought to play a lesser role. Many international organisations have updated their personal protective equipment (PPE) guidelines accordingly. Because N95 or equivalent particulate filtering facepiece respirators (henceforth referred to as ‘respirators’) are more effective than surgical masks against bioaerosols, the World Health Organization, United States Centers for Disease Control and Prevention, and European Centre for Disease Control and Prevention all now recommend that HCWs wear a respirator when caring for individuals thought to have COVID-19. In South Africa, however, surgical masks are still recommended for the routine care of individuals with possible or confirmed COVID-19, with respirators reserved for so-called aerosol-generating procedures. In contrast, South African guidelines recommend the use of respirators for routine care of all individuals with possible or confirmed tuberculosis (TB), which is transmitted almost exclusively via aerosol.In health facilities in South Africa, TB and COVID-19 have similar presentations, may occur together, and often have overlapping risk factors and imaging characteristics. Distinguishing between TB and COVID-19 in individual patients is challenging without examination and investigation, both of which may entail prolonged exposure of HCWs to potentially infectious individuals. Symptom-based triage has limited utility in identifying risk: asymptomatic transmission of SARS-CoV-2 is well recognised, and a high proportion of individuals with pulmonary TB also may not have symptoms. The prevalence of undiagnosed respiratory disease is therefore likely to be significant in many general clinical areas (e.g., waiting areas). HCWs are known to be at higher risk of TB than the general population and thousands of HCWs have developed COVID-19 since the start of the pandemic. A proportion of South African HCWs are also HIV positive, placing them at increased risk of severe COVID-19 disease, hospital admission, and death.Improving infection prevention and control involves implementing a package of administrative, environmental, and personal protection measures, along with substantial reorganisation of systems, care processes, and guidelines to prioritise HCW and patient safety. While this will take time, it is unacceptable to expose HCWs to increased risk until such changes are made. We propose that the South African health system adopts a target of ‘zero harm’, aiming to completely eliminate transmission of respiratory pathogens to all individuals in every health care setting. Accordingly, in line with the precautionary principle, we recommend the use of high quality, fit-tested respirators by all frontline or non-frontline staff (clinical and non-clinical) during activities that involve contact or sharing air in indoor spaces with individuals who (i) have not yet been clinically evaluated or (ii) are thought or known to have TB and/or COVID-19, or other potentially harmful respiratory infections including influenza, measles, and varicella. We recognise that this will be challenging, not least due to global and national shortages of PPE. The National Department of Health’s policy for the regulation of respiratory protective equipment enables a robust framework for manufacture, assessment, and quality control and has been well supported by local manufacture and the South African Department of Trade, Industry and Competition. Manufacturers should explore adaptations to improve comfort of respirators and reduce barriers to communication. The wider use of respirators does not replace the need for structural changes to improve the safety of health facilities: persistent advocacy and research around potential systems change remain essential.
Predictors of discordant latent tuberculosis infection test results amongst South African health care workers
