OUP accepted manuscript

Current methods for tuberculosis treatment monitoring are suboptimal. We evaluated plasma matrix metalloproteinase (MMP) and procollagen III N-terminal propeptide concentrations before and during tuberculosis treatment as biomarkers. Plasma MMP-1, MMP-8, and MMP-10 concentrations significantly decreased during treatment. Plasma MMP-8 was increased in sputum Mycobacterium tuberculosis culture–positive relative to culture-negative participants, before (median, 4993 pg/mL [interquartile range, 2542–9188] vs 698 [218–4060] pg/mL, respectively; P = .004) and after (3650 [1214–3888] vs 720 [551–1321] pg/mL; P = .008) 6 months of tuberculosis treatment. Consequently, plasma MMP-8 is a potential biomarker to enhance tuberculosis treatment monitoring and screen for possible culture positivity.

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.

Urgent need to improve programmatic management of patients with HIV failing first-line antiretroviral therapy

Introduction

Delayed identification and response to virologic failure in case of first-line antiretroviral therapy (ART) in resource-limited settings is a threat to the health of HIV-infected patients. There is a need for the implementation of an effective, standardized response pathway in the public sector.

Discussion

We evaluated published cohorts describing virologic failure on first-line ART. We focused on gaps in the detection and management of treatment failure, and posited ways to close these gaps, keeping in mind scalability and standardization. Specific shortcomings repeatedly recorded included early loss to follow-up (>20%) after recognized first-line ART virologic failure; frequent delays in confirmatory viral load testing; and excessive time between the confirmation of first-line ART failure and initiation of second-line ART, which exceeded 1 year in some cases. Strategies emphasizing patient tracing, resistance testing, drug concentration monitoring, adherence interventions, and streamlined response pathways for those failing therapy are further discussed.

Conclusion

Comprehensive, evidence-based, clinical operational plans must be devised based on findings from existing research and further tested through implementation science research. Until this standard of evidence is available and implemented, high rates of losses from delays in appropriate switch to second-line ART will remain unacceptably common and a threat to the success of global HIV treatment programs.

A packaged intervention to improve viral load monitoring within a deeply rural health district of South Africa

BACKGROUND

The KwaZulu-Natal (KZN) province of South Africa has the highest prevalence of HIV infection in the world. Viral load (VL) testing is a crucial tool for clinical and programmatic monitoring. Within uMkhanyakude district, VL suppression rates were 91% among patients with VL data; however, VL performance rates averaged only 38·7%. The objective of this study was to determine if enhanced clinic processes and community outreach could improve VL monitoring within this district.

METHODS

A packaged intervention was implemented at three rural clinics in the setting of the KZN HIV AIDS Drug Resistance Surveillance Study. This included file hygiene, outreach, a VL register and documentation revisions. Chart audits were used to assess fidelity. Outcome measures included percentage VL performed and suppressed. Each rural clinic was matched with a peri-urban clinic for comparison before and after the start of each phase of the intervention. Monthly sample proportions were modelled using quasi-likelihood regression methods for over-dispersed binomial data.

RESULTS

Mkuze and Jozini clinics increased VL performance overall from 33·9% and 35·3% to 75·8% and 72·4%, respectively which was significantly greater than the increases in the comparison clinics (RR 1·86 and 1·68, p < 0·01). VL suppression rates similarly increased overall by 39·3% and 36·2% (RR 1·84 and 1·70, p < 0·01). The Chart Intervention phase showed significant increases in fidelity 16 months after implementation.

CONCLUSIONS

The packaged intervention improved VL performance and suppression rates overall but was significant in Mkuze and Jozini. Larger sustained efforts will be needed to have a similar impact throughout the province.

Older age at first tuberculosis diagnosis is associated with tuberculosis recurrence in HIV-negative persons

SETTING

Tuberculosis (TB) clinic in Durban, South Africa.

OBJECTIVE

To assess the factors associated with TB recurrence among human immunodeficiency virus (HIV) negative adults and children.

DESIGN

We conducted a retrospective longitudinal study from January 2000 to December 2012. We defined recurrence as a TB episode occurring within the study period after treatment completion or cure of a previous episode. We used a multivariable Poisson regression model to assess the factors associated with the number of recurrences among HIV-negative patients.

RESULTS

Among 17 941 patients with known HIV status, 3653 (20%) were HIV-negative; of these, 235 (6%) had one recurrence, 21 (1%) had two recurrences and 4 (0.1%) had three recurrences. The median follow-up time from the end of treatment for the first episode was 3.0 years (interquartile range 1.9-4.2). Age at the first TB episode was significantly associated with the number of TB recurrences: younger patients had the lowest rate of recurrence, with a steady increase in rates until age 40 years, after which rates stabilized.

CONCLUSIONS

TB recurrence rates among HIV-negative patients were higher at increased age at the first TB episode. Further translational studies are needed to clarify the factors that drive multiple TB recurrences in older age, including impaired immunity, the results of which have implications for TB vaccine development.

Targeting the third '90': introducing the viral load champion

Objective: To move closer to achieving the third target of the UNAIDS 90-90-90 goals, we prospectively implemented a viral load (VL) champion (VLC) program aimed at enhancing VL monitoring and recognition of treatment failure. Design: Three clinics in eThekwini, Kwa-Zulu Natal (low-, medium- and high-volume, encompassing 9184 patients overall) were each assigned a VLC. We employed a descriptive analysis (chart audit) to compare the pre-intervention period to a 1-year post-intervention period. The number of patients with a VL test performed 6 and 12 months after the intervention was calculated as a proportion of VL tests due at those time points (VL completion rate). Results: The pre-implementation VL completion rate at the three sites was respectively 68% (140/205 patients), 54% (84/155 patients) and 64% (323/504 patients), and the 6-month post-implementation completion rate increased to 83% (995/1194 patients), 90% (793/878 patients) and 99% (3101/3124 patients) (P < 0.0001 for each site). VL completion rates remained significantly higher at 12 months post-implementation, with an average cumulative VL completion rate of >90% across all facilities. Conclusion: We demonstrate a successful, multifaceted, quality-improvement intervention centered on a clinic-level VLC which, taken to scale, has important implications for attaining the third UNAIDS 90-90-90 target.

Isoniazid-monoresistant tuberculosis is associated with poor treatment outcomes in Durban, South Africa

SETTING

A large tuberculosis (TB) clinic in Durban, South Africa.

OBJECTIVE

To determine the association between isoniazid (INH) monoresistant TB and treatment outcomes.

DESIGN

We performed a retrospective longitudinal study of patients seen from 2000 to 2012 to compare episodes of INH-monoresistant TB with those of drug-susceptible TB using logistic regression with robust standard errors. INH-monoresistant TB was treated with modified regimens.

RESULTS

Among 18 058 TB patients, there were 19 979 TB episodes for which drug susceptibility testing was performed. Of these, 557 were INH-monoresistant and 16 311 were drug-susceptible. Loss to follow-up, transfer, and human immunodeficiency virus (HIV) co-infection (41% had known HIV status) were similar between groups. INH-monoresistant episodes were more likely to result in treatment failure (4.1% vs. 0.6%, P < 0.001) and death (3.2% vs. 1.8%, P = 0.01) than drug-susceptible episodes. After adjustment for age, sex, race, retreatment status, and disease site, INH-monoresistant episodes were more likely to have resulted in treatment failure (OR 6.84, 95%CI 4.29-10.89, P < 0.001) and death (OR 1.81, 95%CI 1.11-2.95, P = 0.02).

CONCLUSION

INH monoresistance was associated with worse clinical outcomes than drug-susceptible TB. Our findings support the need for rapid diagnostic tests for INH resistance and improved treatment regimens for INH-monoresistant TB.