Advancing TB research using digitized programmatic data

The use of real-world data from national TB care programs has great potential to answer key research questions in TB control and is now opportune due to increasing digital data collection and storage. We summarize an expert stakeholder workshop conducted on this topic in October 2019, with perspectives from academics, national TB program officers, and data managers. We discuss challenges and opportunities in the use of TB programmatic data for research and describe digital data availability in two large, high TB burden countries, Brazil and South Africa. From this, we posit that with a standardized data collection set, improved data management, and greater collaboration, more TB programmatic data can be used for research with measurable public health impact.

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.

Evaluation of the intensified tuberculosis case finding guidelines for children living with HIV

SETTING

Out-patient paediatric human immunodeficiency virus (HIV) clinic in Soweto, South Africa.

OBJECTIVE

To evaluate the yield of symptom screening for intensified tuberculosis (TB) case finding (ICF) and potential eligibility for isoniazid preventive therapy (IPT) in children living with HIV on antiretroviral treatment (ART).

DESIGN

A cohort of 247 children (age 0-8 years) was systematically screened for TB symptoms during the first 2 years of ART. Children with symptoms were assessed using chest X-ray, smear microscopy and culture.

RESULTS

Over 2 years, 1346 TB symptom screens were performed in 220 children not on anti-tuberculosis treatment. Only 48 (3.6%) screens in 39 children were positive for current cough, current fever, weight loss (>5%) or contact with a TB patient. The positive predictive value of symptom screening was 8.9% (95%CI 2.5-21.2); the sensitivity was 57.1% (95%CI 18.4-90.1). Most children (85.8%) were IPT-eligible according to World Health Organization guidelines; however, few (1.2%) were eligible according to South African guidelines.

CONCLUSIONS

The yield of TB symptom screening was relatively poor in children on ART, highlighting the need for future research on paediatric TB symptom screening approaches in this population. The vastly different criteria for IPT eligibility between guidelines suggest that research is also needed to define the optimal use of IPT in children on ART.

Microbiological investigation for tuberculosis among HIV-infected children in Soweto, South Africa

SETTING

A paediatric human immunodeficiency virus (HIV) clinic in an academic hospital in Soweto, South Africa.

OBJECTIVES

1) To describe and compare the clinical, immunological and virological characteristics of HIV-infected children co-treated for tuberculosis (TB), and 2) to compare those investigated microbiologically with those who were not, with a description of the results of the microbiological TB investigation.

DESIGN

Retrospective analysis of TB-HIV-infected children aged <15 years treated for TB between 1 October 2007 and 15 March 2009.

RESULTS

Anti-tuberculosis treatment was initiated in 616/3358 (18%) children during the study period. Microbiological TB investigation results were available for 399/616 (65%), among whom culture-confirmed TB was diagnosed in 49 (12%). Drug susceptibility testing was performed in 29/49 (59%) children: 5/29 (17%) were isoniazid-resistant, and 3 had multidrug-resistant TB. Children aged >8 years and those between 3 and 8 years were more likely to have culture-confirmed TB than those aged <3 years (aOR 9.4, 95%CI 2.26-39.08 vs. aOR 6.7, 95%CI 1.60-27.69), as were those with CD4 count <200 cells/mm(3) compared to those with >500 cells/mm(3) (aOR 3.95, 95%CI 1.23-12.72).

CONCLUSION

Our study in HIV-infected children showed a high TB case rate, a low rate of definite TB and a high rate of drug-resistant TB based on World Health Organization case definitions. Increased uptake of available TB tests and availability of new diagnostic tests remains a priority in high TB-HIV burden settings.

HAART and risk of tuberculosis in HIV-infected South African children: a multi-site retrospective cohort

SETTING

Four human immunodeficiency virus (HIV) clinics located at South African tertiary hospitals.

OBJECTIVE

To assess the effectiveness of highly active antiretroviral therapy (HAART) in reducing incident tuberculosis (TB) in HIV-infected children.

DESIGN

Retrospective cohort.

RESULTS

A total of 1132 children's records were included in the study. At entry to the cohort, the median (interquartile range [IQR]) age, CD4%, CD4 count and viral load of all children was respectively 6.3 years (4.1-8.8), 15% (9.0-22.2), 576 cells/mm(3) (287-960) and 160 000 copies/ml (54 941.5-449 683); 75.9% were started on HAART. The male:female ratio was 1:1, and median follow-up time was 1.7 years. In children whose follow-up included both pre-HAART and on-HAART periods, the incidence of clinically diagnosed TB was respectively 21.1 per 100 person-years (py; 95%CI 18.2-24.4) and 6.4/100 py (95%CI 4.8-8.1), and when restricted to confirmed cases, respectively 3.1/100 py (95%CI 2.2-4.2) and 0.8/100 py (95%CI 0.5-1.4). Only 23% of all cases of TB were microbiologically confirmed. Multivariate analyses showed that HAART reduced incident TB by approximately 70%, both for confirmed and all TB cases.

CONCLUSIONS

In this high TB burden country, the incidence of diagnosis of TB in HIV-infected children is at least as high as that of adults. HAART reduces incident TB, but further prospective TB preventive and diagnostic studies are urgently needed in children.