Multilevel factors affecting tuberculosis diagnosis and initial treatment

Global, regional, and national sex differences in the global burden of tuberculosis by HIV status, 1990-2019: results from the Global Burden of Disease Study 2019

BACKGROUND

Tuberculosis is a major contributor to the global burden of disease, causing more than a million deaths annually. Given an emphasis on equity in access to diagnosis and treatment of tuberculosis in global health targets, evaluations of differences in tuberculosis burden by sex are crucial. We aimed to assess the levels and trends of the global burden of tuberculosis, with an emphasis on investigating differences in sex by HIV status for 204 countries and territories from 1990 to 2019.

METHODS

We used a Bayesian hierarchical Cause of Death Ensemble model (CODEm) platform to analyse 21 505 site-years of vital registration data, 705 site-years of verbal autopsy data, 825 site-years of sample-based vital registration data, and 680 site-years of mortality surveillance data to estimate mortality due to tuberculosis among HIV-negative individuals. We used a population attributable fraction approach to estimate mortality related to HIV and tuberculosis coinfection. A compartmental meta-regression tool (DisMod-MR 2.1) was then used to synthesise all available data sources, including prevalence surveys, annual case notifications, population-based tuberculin surveys, and tuberculosis cause-specific mortality, to produce estimates of incidence, prevalence, and mortality that were internally consistent. We further estimated the fraction of tuberculosis mortality that is attributable to independent effects of risk factors, including smoking, alcohol use, and diabetes, for HIV-negative individuals. For individuals with HIV and tuberculosis coinfection, we assessed mortality attributable to HIV risk factors including unsafe sex, intimate partner violence (only estimated among females), and injection drug use. We present 95% uncertainty intervals for all estimates.

FINDINGS

Globally, in 2019, among HIV-negative individuals, there were 1·18 million (95% uncertainty interval 1·08-1·29) deaths due to tuberculosis and 8·50 million (7·45-9·73) incident cases of tuberculosis. Among HIV-positive individuals, there were 217 000 (153 000-279 000) deaths due to tuberculosis and 1·15 million (1·01-1·32) incident cases in 2019. More deaths and incident cases occurred in males than in females among HIV-negative individuals globally in 2019, with 342 000 (234 000-425 000) more deaths and 1·01 million (0·82-1·23) more incident cases in males than in females. Among HIV-positive individuals, 6250 (1820-11 400) more deaths and 81 100 (63 300-100 000) more incident cases occurred among females than among males in 2019. Age-standardised mortality rates among HIV-negative males were more than two times greater in 105 countries and age-standardised incidence rates were more than 1·5 times greater in 74 countries than among HIV-negative females in 2019. The fraction of global tuberculosis deaths among HIV-negative individuals attributable to alcohol use, smoking, and diabetes was 4·27 (3·69-5·02), 6·17 (5·48-7·02), and 1·17 (1·07-1·28) times higher, respectively, among males than among females in 2019. Among individuals with HIV and tuberculosis coinfection, the fraction of mortality attributable to injection drug use was 2·23 (2·03-2·44) times greater among males than females, whereas the fraction due to unsafe sex was 1·06 (1·05-1·08) times greater among females than males.

INTERPRETATION

As countries refine national tuberculosis programmes and strategies to end the tuberculosis epidemic, the excess burden experienced by males is important. Interventions are needed to actively communicate, especially to men, the importance of early diagnosis and treatment. These interventions should occur in parallel with efforts to minimise excess HIV burden among women in the highest HIV burden countries that are contributing to excess HIV and tuberculosis coinfection burden for females. Placing a focus on tuberculosis burden among HIV-negative males and HIV and tuberculosis coinfection among females might help to diminish the overall burden of tuberculosis. This strategy will be crucial in reaching both equity and burden targets outlined by global health milestones.

FUNDING

Bill & Melinda Gates Foundation.

Improved appropriateness of anti-tuberculosis prescription by the expert prescription review program in Taiwan

BACKGROUND

A nationwide program initiated by Taiwan CDC was conducted by the Taiwan Society of Tuberculosis and Lung Disease to improve the appropriateness of anti-TB prescriptions in Taiwan.

METHODS

All anti-TB prescriptions from 12 hospitals across Taiwan were reviewed by experienced pulmonologists, according to the 2011 Taiwan TB treatment guidelines, between May and October 2013. The investigation period was divided into three stages: May to June, July to August, and September to October. The concordance rates between anti-TB prescriptions and the guidelines were compared among the three stages and between medical centers and regional hospitals.

RESULTS

A total of 2574 new anti-TB prescriptions were reviewed. The appropriateness of anti-TB prescriptions was 82.0%. The most dominant error was inappropriate dosage of anti-TB medications. The appropriateness improved significantly with prescription review, and the concordance rates were 78.7%, 80.6%, and 87.6% in stages 1, 2, and 3, respectively (P < 0.001). The inappropriateness of medication dosage also improved significantly, with the rates of inappropriate dosage dropping from 10.2% in stage 1-5.4% in stage 3 (Odds ratio 0.491, P < 0.001). The appropriateness rates showed no significant difference between regional hospitals and medical centers (82.5% vs. 81.3%, Odds ratio 0.915, P = 0.393), but the improvement of prescription appropriateness was significant in regional hospitals but not in medical centers.

CONCLUSION

Prescription review by TB experts is an effective approach to improve the appropriateness of anti-TB prescriptions.

An audit of diagnosis and treatment of tuberculosis in Ethiopia

BACKGROUND

Despite the existence of national tuberculosis guidelines (NTG) in Ethiopia, the incidence and prevalence of tuberculosis did not decline markedly. Audits could attempt to determine whether or not healthcare professionals actually implemented these guidelines, as non-implementation could contribute to suboptimal tuberculosis treatment outcomes.

AIM

To evaluate healthcare providers' implementation of Ethiopia's NTG during the diagnosis and treatment of tuberculosis in order to enhance tuberculosis treatment outcomes.

METHODS

A descriptive, cross-sectional study design was used.

RESULTS

Healthcare providers implemented the NTG during tuberculosis diagnosis for female (60.9%; n = 67) and male (56.1%; n = 69) patients. The correct numbers of anti-tuberculosis pills, complying with the NTG recommendations, were prescribed for 91.8% (n = 101) of the women and for 90.2% (n = 111) of the men. However, both over- and under-prescriptions of anti-tuberculosis drugs occurred. There was an over-diagnosis of smear-negative pulmonary tuberculosis. Only 2.6% (n = 2) of the 76 smear-negative pulmonary tuberculosis patients had been diagnosed correctly.

CONCLUSION

Implementation of the NTG should be enhanced, especially with regard to the diagnosis of smear-negative pulmonary tuberculosis patients and the correct prescription of anti-tuberculosis drugs. This would help to increase the number of correctly-diagnosed and -treated tuberculosis patients, improve tuberculosis treatment outcomes, decrease the spread of tuberculosis and prevent the development of multi-drug-resistant tuberculosis strains.

Development of a quantitative sandwich enzyme-linked immunosorbent assay for detecting the MPT64 antigen of Mycobacterium tuberculosis

PURPOSE

Tuberculosis (TB) is a major infectious disease and is responsible for two million deaths annually. For the identification and quantitation of Mycobacterium tuberculosis (M. tuberculosis), a causative agent of TB, a sandwich enzyme-linked immunosorbent assay (ELISA) against the MPT64 protein of M. tuberculosis, an antigen marker of the M. tuberculosis complex, was developed.

MATERIALS AND METHODS

The MPT64 protein was expressed, and anti-MPT64 monoclonal antibodies were prepared. A sandwich ELISA was established using recombinant MPT64 protein and anti-MPT64 monoclonal antibodies. The sandwich MPT64 ELISA was evaluated using reference and clinical mycobacterial strains.

RESULTS

The sandwich MPT64 ELISA detected MPT64 protein from 2.1 ng/mL to 250 ng/mL (equivalent to 1.7×10⁴ CFU/mL and 2.0×10⁶ CFU/mL). All 389 clinical M. tuberculosis isolates tested positive in the sandwich MPT64 ELISA (sensitivity, 100%), and the assay showed no cross reactivity to any tested nontuberculous mycobacterial strain (specificity, 100%).

CONCLUSION

The sandwich MPT64 ELISA is a highly sensitive and quantitative test for MPT64 protein, which can identify M. tuberculosis.

Barriers and delays in tuberculosis diagnosis and treatment services: does gender matter?

Background. Tuberculosis (TB) remains a global public health problem with known gender-related disparities. We reviewed the quantitative evidence for gender-related differences in accessing TB services from symptom onset to treatment initiation. Methods. Following a systematic review process, we: searched 12 electronic databases; included quantitative studies assessing gender differences in accessing TB diagnostic and treatment services; abstracted data; and assessed study validity. We defined barriers and delays at the individual and provider/system levels using a conceptual framework of the TB care continuum and examined gender-related differences. Results. Among 13,448 articles, 137 were included: many assessed individual-level barriers (52%) and delays (42%), 76% surveyed persons presenting for care with diagnosed or suspected TB, 24% surveyed community members, and two-thirds were from African and Asian regions. Many studies reported no gender differences. Among studies reporting disparities, women faced greater barriers (financial: 64% versus 36%; physical: 100% versus 0%; stigma: 85% versus 15%; health literacy: 67% versus 33%; and provider-/system-level: 100% versus 0%) and longer delays (presentation to diagnosis: 45% versus 0%) than men. Conclusions. Many studies found no quantitative gender-related differences in barriers and delays limiting access to TB services. When differences were identified, women experienced greater barriers and longer delays than men.

Sex disparities in tuberculosis suspect evaluation: a cross-sectional analysis in rural Uganda

SETTING

Six primary health care centers in rural Uganda.

OBJECTIVE

To compare the quality of tuberculosis (TB) evaluation for men and women presenting to primary health care facilities in high-burden settings.

DESIGN

Cross-sectional study using indicators derived from the International Standards of Tuberculosis Care (ISTC) to compare the quality of TB evaluation services provided to men and women.

RESULTS

Of 161 230 patient visits between January 2009 and December 2010, 112 329 (69.7%) were women. We considered 3308 (2.1%) patients with cough ≥2 weeks as TB suspects, of whom 1871 (56.6%) were women. Female TB suspects were less likely to be referred for sputum smear examination (45.9% vs. 61.6%, P < 0.001), to complete sputum smear examination if referred (73.7% vs. 78.3%, P = 0.024) and to receive comprehensive evaluation and care as defined by the ISTC (33.0% vs. 45.6%, P < 0.001). After adjusting for age, clinic site and visit date, women remained less likely to be referred for sputum smear examination (risk ratio [RR] 0.81, 95%CI 0.74-0.89, P < 0.001) and to receive ISTC-recommended care (RR 0.79, 95%CI 0.72-0.86, P < 0.001).

CONCLUSION

Strategies to ensure that women receive appropriate TB evaluation could provide a valuable opportunity for increasing case detection while also promoting equitable and universal access to care.

Diagnostic accuracy of same-day microscopy versus standard microscopy for pulmonary tuberculosis: a systematic review and meta-analysis

BACKGROUND

Sputum smear microscopy is the most widely available diagnostic test for pulmonary tuberculosis in countries with a high burden of the disease. Improving its accuracy is crucial to achievement of case-detection targets established by the Millennium Development Goals. Unfortunately, many patients are unable to submit all of the specimens needed for examination or to return for treatment because standard sputum collection and reporting requires several clinic visits. To inform policy recommendations by a WHO-convened Expert Group, we aimed to assess the accuracy of sputum smear examination with strategies for obtaining sputum on 1 day compared with strategies for obtaining sputum over 2 days.

METHODS

We did a systematic review and meta-analysis of research articles comparing the accuracy of front-loaded or same-day microscopy and standard sputum smear microscopy for diagnosis of culture-confirmed pulmonary tuberculosis. We searched Medline, Embase, Biosis, and Web of Science for articles published between Jan 1, 2005, and Feb 14, 2012. Two investigators identified eligible articles and extracted data for individual study sites. We generated pooled summary estimates (95% CIs) for sensitivity and specificity by use of random-effects meta-analysis when four or more studies were available.

FINDINGS

We identified eight relevant studies from five articles enrolling 7771 patients with suspected tuberculosis in low-income countries. Compared with the standard approach of examination of two smears with Ziehl-Neelsen light microscopy over 2 days, examination of two smears taken on the same day had much the same sensitivity (64% [95% CI 60 to 69] for standard microscopy vs 63% [58 to 68] for same-day microscopy) and specificity (98% [97 to 99] vs 98% [97 to 99]). We noted similar results for studies employing light-emitting diode fluorescence microscopy and for studies examining three smears, whether they were compared with two-smear strategies or with one another.

INTERPRETATION

Same-day sputum smear microscopy is as accurate as standard smear microscopy. Data from tuberculosis programmes are needed to document the changes required in the health system to successfully implement the strategy and understand its effects.

FUNDING

WHO and US National Institutes of Health.

Prevalence of inappropriate tuberculosis treatment regimens: a systematic review

A potential threat to the success of new tuberculosis (TB) drugs is the development of resistance. Using drugs in appropriate regimens, such as those recommended in the World Health Organization (WHO) treatment guidelines, prevents the development of resistance. We performed a systematic review to assess the prevalence of inappropriate prescription of TB drugs for the treatment of TB.

MEDLINE, EMBASE and other databases were searched for relevant articles in January 2011. Observational studies published from 2000 that included TB patients receiving treatment were selected. A treatment regimen was considered inappropriate if the regimen was not a WHO recommended regimen.

37 studies were included. Inappropriate treatment regimens were prescribed in 67% of studies. The percentage of patients receiving inappropriate regimens varied between 0.4% and 100%. In 19 studies the quality of treatment regimen reporting was low.

Despite the fact that assessment of inappropriate treatment was hampered by low quality of reporting, our data indicate a reasonable amount of inappropriate prescription of TB treatment regimens. Thus, there is a risk that new drugs will be used in inappropriate treatment regimens, even with WHO guidelines in place, introducing the risk of resistance development. This article highlights the need to improve implementation of the WHO treatment of TB guidelines.

A multi-country non-inferiority cluster randomized trial of frontloaded smear microscopy for the diagnosis of pulmonary tuberculosis

BACKGROUND

More than 50 million people around the world are investigated for tuberculosis using sputum smear microscopy annually. This process requires repeated visits and patients often drop out.

METHODS AND FINDINGS

This clinical trial of adults with cough ≥2 wk duration (in Ethiopia, Nepal, Nigeria, and Yemen) compared the sensitivity/specificity of two sputum samples collected "on the spot" during the first visit plus one sputum sample collected the following morning (spot-spot-morning [SSM]) versus the standard spot-morning-spot (SMS) scheme. Analyses were per protocol analysis (PPA) and intention to treat (ITT). A sub-analysis compared just the first two smears of each scheme, spot-spot and spot-morning. In total, 6,627 patients (3,052 SSM/3,575 SMS) were enrolled; 6,466 had culture and 1,526 were culture-positive. The sensitivity of SSM (ITT, 70.2%, 95% CI 66.5%-73.9%) was non-inferior to the sensitivity of SMS (PPA, 65.9%, 95% CI 62.3%-69.5%). Similarly, the specificity of SSM (ITT, 96.9%, 95% CI 93.2%-99.9%) was non-inferior to the specificity of SMS (ITT, 97.6%, 95% CI 94.0%-99.9%). The sensitivity of spot-spot (ITT, 63.6%, 95% CI 59.7%-67.5%) was also non-inferior to spot-morning (ITT, 64.8%, 95% CI 61.3%-68.3%), as the difference was within the selected -5% non-inferiority limit (difference ITT = 1.4%, 95% CI -3.7% to 6.6%). Patients screened using the SSM scheme were more likely to provide the first two specimens than patients screened with the SMS scheme (98% versus 94.2%, p<0.01). The PPA and ITT analysis resulted in similar results.

CONCLUSIONS

The sensitivity and specificity of SSM are non-inferior to those of SMS, with a higher proportion of patients submitting specimens. The scheme identifies most smear-positive patients on the first day of consultation.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN53339491. Please see later in the article for the Editors' Summary.