A position statement and practical guide to the use of particulate filtering facepiece respirators (N95, FFP2, or equivalent) for South African health workers exposed to respiratory pathogens including Mycobacterium tuberculosis and SARS-CoV-2

SUMMARY

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is transmitted mainly by aerosol in particles <10 µm that can remain suspended for hours before being inhaled. Because particulate filtering facepiece respirators ('respirators'; e.g. N95 masks) are more effective than surgical masks against bio-aerosols, many international organisations now recommend that health workers (HWs) wear a respirator when caring for individuals who may have COVID-19. In South Africa (SA), 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, SA guidelines do recommend respirators for routine care of individuals with possible or confirmed tuberculosis (TB), which is also transmitted via aerosol. In health facilities in SA, distinguishing between TB and COVID-19 is challenging without examination and investigation, both of which may expose HWs to potentially infectious individuals. Symptom-based triage has limited utility in defining risk. Indeed, significant proportions of individuals with COVID-19 and/or pulmonary TB may not have symptoms and/or test negative. The prevalence of undiagnosed respiratory disease is therefore likely significant in many general clinical areas (e.g. waiting areas). Moreover, a proportion of HWs are HIV-positive and are at increased risk of severe COVID-19 and death.

RECOMMENDATIONS

Sustained improvements in infection prevention and control (IPC) require reorganisation of systems to prioritise HW and patient safety. While this will take time, it is unacceptable to leave HWs exposed until such changes are made. We propose that the SA health system adopts a target of 'zero harm', aiming to eliminate transmission of respiratory pathogens to all individuals in every healthcare setting. Accordingly, we recommend: the use of respirators by all 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;the use of respirators that meet national and international manufacturing standards;evaluation of all respirators, at the least, by qualitative fit testing; andthe use of respirators as part of a 'package of care' in line with international IPC recommendations. We recognise that this will be challenging, not least due to global and national shortages of personal protective equipment (PPE). SA national policy around respiratory protective equipment enables a robust framework for manufacture and quality control and has been supported by local manufacturers and the Department of Trade, Industry and Competition. Respirator manufacturers should explore adaptations to improve comfort and reduce barriers to communication. Structural changes are needed urgently to improve the safety of health facilities: persistent advocacy and research around potential systems change remain essential.

Tuberculosis retreatment category predicts resistance in hospitalized retreatment patients in a high HIV prevalence area

SETTING

Rates of multidrug-resistant tuberculosis (MDR-TB) are currently as high as 7.7% in retreatment cases in KwaZulu-Natal, South Africa. MDR-TB prevalence is known to be high in patients categorized as treatment failures. Recent reports have questioned the effectiveness of the World Health Organization (WHO) Category II regimen in retreatment TB cases.

OBJECTIVE

To determine whether treatment category predicts susceptibility patterns and outcomes in a hospitalized population of retreatment TB cases.

DESIGN

Retrospective cohort of 197 pulmonary retreatment cases.

RESULTS

Retreatment cases treated with the standard retreatment regimen had a high in-hospital mortality (19.8%), or poor outcome (26.4%) and a high rate of MDR-TB (16.2%). The 'treatment failure' category predicted resistance, with 57.1% of patients exhibiting any resistance compared to other treatment categories (P = 0.02); 53.8% of patients with any resistance experienced poor outcomes, compared to 16.6% of pan-susceptible cases (P = 0.02). There was a trend towards poor outcome in the treatment failure category (42.9%, P = 0.13).

CONCLUSION

The retreatment category 'treatment failure' is associated with a high prevalence of resistance in an area of high human immunodeficiency virus (HIV) prevalence. The 'treatment failure' category should be used to identify patients who may benefit from alternative regimens using directed, intensified therapy or second-line agents instead of the current standard retreatment regimen.

Characteristics of HIV-1-associated Kaposi's sarcoma among women and men in South Africa

Despite the increase of HIV-1-associated Kaposi's sarcoma (KS), little is known about HIV-associated KS in the African setting, particularly among women. A descriptive study of the demographic, clinical, immunological and virological features of AIDS-associated KS from KwaZulu-Natal, South Africa was undertaken. Consecutively, recruited patients were clinically staged; CD4/CD8 cell counts, HIV-1 viral loads and clinical parameters were evaluated. Of the 152 patients (77 male and 75 female) 99% were black. Females were significantly younger (P = 0.02) and had poorer disease prognosis (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.4-5.4, P = 0.003) and were more likely to have extensive cutaneous KS when compared with males (OR = 3.1, 95% CI = 1.4-6.7, P = 0.003). One-third of patients had coexisting HIV-related disease, most commonly tuberculosis, and these were more frequent in females (56.7 vs. 43.3%). In conclusion, HIV-associated KS in South Africans has an equal female-to-male ratio. Females are younger and have more severe disease than males.

Pre-collisional anastomosing shear zones in the Kohistan arc, NW Pakistan

Ductile strain localization commonly forms a pattern of shear zones anastomosing around lenses of less deformed rock. Initiation and development of anastomosing shear zones are studied through description of the structures and deformation history of plutonic rocks that form the lower crust of the Kohistan arc. Structures and textures developed in these rocks result from primary magmatic to solid state regional strain, overprinted by anastomosing shear zones. The primary strain was mainly acquired during magmatic emplacement at 100-90 Ma. Strain localization took place continuously from magmatic emplacement to solid state deformation during cooling of the plutons and formed three successive sets of shear zones. Set 1 is composed of associated discrete Riedel and thrust shear zones developed above solidus conditions during southwestward thrusting. Continuous deformation from solidus to amphibolite facies conditions between 100 and 83 Ma formed the second set of shear zones. The lower amphibolite facies set 3 shear zones are diffeentiated by larger strains recorded in the thicker mylonitic zones and enlargement of the spacing between shear zones during cooling. The anastomosing pattern of shear zones described here probably represents arc-related deformation during subduction of the Tethys oceanic lithosphere below the Kohistan arc.