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.

Pulmonary hypertension: Spectrum of disease, clinical presentation and treatment outcomes at the main respiratory pulmonary hypertension clinic in KwaZulu-Natal Province, South Africa

BACKGROUND

There are many causes of pulmonary hypertension (PH). However, the aetiology, management and treatment outcomes in South Africa (SA), which has a high burden of HIV, are lacking in the literature.

OBJECTIVES

To characterise patient demographics, aetiology, clinical presentation and management of patients presenting to the only government-funded PH clinic in Durban, SA.

METHODS

We retrospectively reviewed electronic charts of patients with confirmed PH who attended the respiratory PH clinic between 2011 and 2018. Demographic and clinical data, symptoms, pulmonary function testing, pulmonary artery pressure on echocardiography and treatment were analysed. Patients with group 2 PH were excluded from the present study as they were managed by cardiologists.

RESULTS

We identified 93 patients with confirmed PH and the majority were female (82.8%; n=77). The majority of the patients were between the ages of 30 and 39 years at the time of diagnosis. Most patients were black African (64.5%; n=60), followed by Indians (26.9%; n=25) and whites (8.6%; n=8). The most common cause of PH was group 1 (75%; n=70), followed by group 4 (13%; n=12) and then group 3 (12%; n=11). HIV-associated PH accounted for 27% of all patients and was the main cause of PH in those classified in group 1 (38%; n=29). Two-thirds (66%) of patients were treated with sildenafil, the only treatment that was available. Patients on treatment showed significant improvement indicated by the World Health Organization functional class, mean 6-minute walk test and reduction in mean pulmonary artery pressure on echocardiography.

CONCLUSION

HIV-associated PH is the most common cause of PH in SA. Sildenafil, the only drug available in our setting, is beneficial to most patients with PH.

Guideline for the management of chronic obstructive pulmonary disease--2011 update

OBJECTIVE

To revise the South African Guideline for the Management of Chronic Obstructive Pulmonary Disease (COPD) based on emerging research that has informed updated recommendations.

KEY POINTS

(1) Smoking is the major cause of COPD, but exposure to biomass fuels and tuberculosis are important additional factors. (2) Spirometry is essential for the diagnosis and staging of COPD. (3) COPD is either undiagnosed or diagnosed too late, so limiting the benefit of therapeutic interventions; performing spirometry in at-risk individuals will help to establish an early diagnosis. (4) Oral corticosteroids are no longer recommended for maintenance treatment of COPD. (5) A therapeutic trial of oral corticosteroids to distinguish corticosteroid responders from non-responders is no longer recommended. (6) Primary and secondary prevention are the most cost-effective strategies in COPD. Smoking cessation as well as avoidance of other forms of pollution can prevent disease in susceptible individuals and ameliorate progression. Bronchodilators are the mainstay of pharmacotherapy, relieving dyspnoea and improving quality of life. (7) Inhaled corticosteroids are recommended in patients with frequent exacerbations and have a synergistic effect with bronchodilators in improving lung function, quality of life and exacerbation frequency. (8) Acute exacerbations of COPD significantly affect morbidity, health care units and mortality. (9) Antibiotics are only indicated for purulent exacerbations of chronic bronchitis. (10) COPD patients should be encouraged to engage in an active lifestyle and participate in rehabilitation programmes.

OPTIONS

Treatment recommendations are based on the following: annual updates of the Global Obstructive Lung Disease (GOLD), initiative, that provide an evidence-based comprehensive review of management; independent evaluation of the level of evidence in support of some of the new treatment trends; and consideration of factors that influence COPD management in South Africa, including lung co-morbidity and drug availability and cost.

OUTCOME

Holistic management utilising pharmacological and nonpharmacological options are put in perspective.

EVIDENCE

Working groups of clinicians and clinical researchers following detailed literature review, particularly of studies performed in South Africa, and the GOLD guidelines. BENEFITS, HARMS AND COSTS. The guideline pays particular attention to cost-effectiveness in South Africa, and promotes the initial use of less costly options. It promotes smoking cessation and selection of treatment based on objective evidence of benefit. It also rejects a nihilistic or punitive approach, even in those who are unable to break the smoking addiction.

RECOMMENDATIONS

These include primary and secondary prevention; early diagnosis, staging of severity, use of bronchodilators and other forms of treatment, rehabilitation, and treatment of complications. Advice is provided on the management of acute exacerbations and the approach to air travel, prescribing long-term oxygen and lung surgery including lung volume reduction surgery.

VALIDATION

The COPD Working Group comprised experienced pulmonologists representing all university departments in South Africa and some from private practice, and general practitioners. Most contributed to the development of the previous version of the South African guideline. GUIDELINE SPONSOR: The meeting of the Working Group of the South African Thoracic Society was sponsored by an unrestricted educational grant from Boehringer Ingelheim and Glaxo-Smith-Kline.

TB presenting as community-acquired pneumonia in a setting of high TB incidence and high HIV prevalence

SETTING

Sub-Saharan Africa has the highest prevalence of human immunodeficiency virus (HIV)/acquired immune-deficiency syndrome (AIDS) and a high incidence of tuberculosis (TB).

OBJECTIVES

To determine the aetiology of and mortality due to community-acquired pneumonia (CAP) in HIV and non-HIV-infected adults.

METHODS

Consecutive patients with CAP admitted to a teaching hospital in KwaZulu-Natal over a 17-month period were studied prospectively. Systematic investigation of samples of sputum and blood cultures was performed. A subset of patients had urine antigen tests and serum serology.

RESULTS

A total of 430 patients with a mean age of 33 years (range 18-82) were enrolled. Of the 382 patients tested, 311 (81.4%) were HIV-infected. Pathogens were isolated in 222 patients (52%). The most common organisms were Mycobacterium tuberculosis (39.6%) and Streptococcus pneumoniae (34.5%). M. tuberculosis was the most common agent in both HIV and non-HIV-infected subjects (40% and 35%, respectively). In-hospital mortality was 17% overall, 15.9% in the HIV-infected, 25% in the non-HIV-infected and 38% in patients with polymicrobial infections.

CONCLUSIONS

M. tuberculosis was the leading cause of CAP and reflects the worsening TB epidemic in the region. Aggressive intervention is required to address both the HIV and TB epidemics in sub-Saharan Africa.

Poor adherence to South African guidelines for the management of community-acquired pneumonia

OBJECTIVE

To evaluate adherence to the South African guidelines for the management of community-acquired pneumonia (CAP) and to determine whether adherence reduced length of hospital stay and mortality in patients with severe CAP.

SETTING

King Edward VIII Hospital, Durban.

METHODS

Four hundred and thirty patients with CAP were recruited between June 2000 and October 2001. Severity assessment data were collected. Severe CAP was defined by the presence of two or more markers. Without influence from the investigators, the admitting team chose the empirical antibiotic regimen. Antibiotics administered, outcome and length of stay were analysed.

RESULTS

Two hundred and eighty-seven of 430 patients were eligible for analysis. One hundred and eighty-two patients had two or more markers of severe CAP. Fourteen of the 182 patients (8%) had initial antibiotic therapy administered according to South African guidelines and 168 (92%) did not. The mortality rate was 20% (36 patients). Accounting for sample size there was no statistically significant difference in length of stay between the two groups (14 v. 12 days, p = 1.0000, odds ratio (OR) 1.167, 95% confidence interval (CI): 0.3926 - 3.467) or in mortality rate (28.5% v. 19%, p = 0.3549, OR 1.667, 95% CI: 0.667 - 4.161).

CONCLUSION

There was very poor adherence with South African CAP antibiotic guidelines. The sample size of patients receiving treatment according to the South African Thoracic Society (SATS) guidelines was too low to confirm confidently that adherence may have resulted in a clinical benefit.

Comparison of plain chest radiography and high-resolution CT in human immunodeficiency virus infected patients with community-acquired pneumonia: a sub-Saharan Africa study

The objective of the study was to determine the proportion of patients with missed lesions on plain chest radiographs compared with high-resolution computed tomography (HRCT) in 49 human immunodeficiency virus (HIV) infected patients with community-acquired pneumonia (CAP). Patients underwent plain chest radiography and HRCT scans of the chest at admission. Microbiological investigations for CAP were performed. An experienced radiologist, without knowledge of clinical or pathological data, reported the chest radiographs and HRCT scans. The study group included 26 females and 23 males, aged 18-53 years (mean age 36 years). Organisms were isolated from 26 patients (53%). In 40 patients (82%), the HRCT scans demonstrated lesions not visualized on the plain chest radiographs. There was 100% correlation between plain radiographic and HRCT scan findings in nine cases (18%). Lesions that were not visualized on the plain radiographs but elucidated on HRCT included: pleural effusion (n = 14), ground-glass opacification (n = 20), pericardial effusion (n = 8), cavitation (n = 4), cysts (n = 4), bullae (n = 4), abscess (n = 1) and pneumothorax (n = 1). In 20 of 23 cases, hilar lymphadenopathy, identified on HRCT, was not recognized on plain chest radiographs. In patients in whom an organism was isolated, a correct HRCT diagnosis of pulmonary tuberculosis, bacterial pneumonia and Pneumocystis carinii pneumonia (PCP) was made in 80%, 84% and 100% of cases, respectively. The proportion of patients with missed lesions on plain chest radiographs in HIV infected patients with CAP was high. This has important implications for management and prognosis. HRCT scans correlate well with the microbiological diagnosis when reported by an experienced radiologist.

Serum procalcitonin distinguishes CAP due to bacteria, Mycobacterium tuberculosis and PJP

SETTING

Procalcitonin (PCT), a propeptide of the hormone calcitonin, is a novel marker of the inflammatory response to infection. It has been used to discriminate between infectious and non-infectious causes of inflammation, and as a marker of severe sepsis in the intensive care unit.

OBJECTIVE

To evaluate the utility of PCT in distinguishing community-acquired pneumonia (CAP) due to common bacteria, Mycobacterium tuberculosis and Pneumocystis jirovecii in a high human immunodeficiency virus (HIV) prevalence setting.

METHODS

Two hundred and sixty-six patients admitted with a diagnosis of CAP were investigated. Serum samples for PCT were collected on admission. PCT levels were measured using a commercial immunoluminometric assay.

RESULTS

A microbiological diagnosis was obtained in 169/266 patients: 44 pulmonary tuberculosis (PTB), 31 P. jirovecii pneumonia (PJP), and 35 bacterial pneumonia. The PCT levels were PTB 4.16 ng/ml (SEM 1.197; 95% CI 1.749-6.579); PJP 1.138 ng/ml (SEM 0.2911; 95% CI 0.543-1.734); and bacterial pneumonia 19.48 ng/ml (SEM 5.64; 95% CI 8.021-30.938, P < 0.0004). Thirty-six had co-infections.

CONCLUSION

PCT levels differ significantly in patients with CAP due to TB, PJP and bacteria. PCT may be important in distinguishing M. tuberculosis and PJP in a high HIV prevalence setting where atypical presentations often confound the empirical clinical diagnosis.

Pulmonary hypertension: pathogenesis and management

Notable progress has been achieved in our understanding of the pathogenesis of pulmonary hypertension, in particular the role of vasodilators, vasoconstrictors and the intracellular signaling pathways, cytokines, chemokines and growth factors involved. A comprehensive history and clinical examination is mandatory in the assessment and determination of the cause of pulmonary hypertension. This should be complemented by a rationale approach to investigation. Treatment of secondary pulmonary hypertension involves targeting the underlying cause. General measures include oxygen therapy and judicious use of diuretics in patients with overt right heart failure. Newer therapies that have been developed for the treatment of idiopathic pulmonary hypertension include prostanoids, modulators of vascular remodelling such as bosentan and its analogues and PGE-5 inhibitors such as sildenafil. New therapies are likely to become available in the future as our understanding of the pathogenesis of pulmonary hypertension evolves.