Pulmonary Tuberculosis In South Africa Research Articles

Quantitation of Circulating Mycobacterium tuberculosis Antigens by Nanopore Biosensing in Children Evaluated for Pulmonary Tuberculosis in South Africa.

Nanopore sensing of proteomic biomarkers lacks accuracy due to the ultralow abundance of targets, a wide variety of interferents in clinical samples, and the mismatch between pore and analyte sizes. By converting antigens to DNA probes via click chemistry and quantifying their characteristic signals, we show a nanopore assay with several amplification mechanisms to achieve an attomolar level limit of detection that enables quantitation of the circulating Mycobacterium tuberculosis (Mtb) antigen ESAT-6/CFP-10 complex in human serum. The assay's nonsputum-based feature and low-volume sample requirements make it particularly well-suited for detecting pediatric tuberculosis (TB) disease, where establishing an accurate diagnosis is greatly complicated by the paucibacillary nature of respiratory secretions, nonspecific symptoms, and challenges with sample collection. In the clinical assessment, the assay was applied to analyze ESAT-6/CFP-10 levels in serum samples collected during baseline investigation for TB in 75 children, aged 0-12 years, enrolled in a diagnostic study conducted in Cape Town, South Africa. This nanopore assay showed superior sensitivity in children with confirmed TB (94.4%) compared to clinical "gold standard" diagnostic technologies (Xpert MTB/RIF 44.4% and Mtb culture 72.2%) and filled the diagnostic gap for children with unconfirmed TB, where these traditional technologies fell short. We envision that, in combination with automated sample processing and portable nanopore devices, this methodology will offer a powerful tool to support the diagnosis of pulmonary TB in children.

Prevalence of bacteriologically confirmed pulmonary tuberculosis in South Africa, 2017–19: a multistage, cluster-based, cross-sectional survey

SummaryBackgroundTuberculosis remains an important clinical and public health issue in South Africa, which has one of the highest tuberculosis burdens in the world. We aimed to estimate the burden of bacteriologically confirmed pulmonary tuberculosis among people aged 15 years or older in South Africa.MethodsThis multistage, cluster-based, cross-sectional survey included eligible residents (age ≥15 years, who had slept in a house for ≥10 nights in the preceding 2 weeks) in 110 clusters nationally (cluster size of 500 people; selected by probability proportional-to-population size sampling). Participants completed face-to-face symptom questionnaires (for cough, weight loss, fever, and night sweats) and manually read digital chest X-ray screening. Screening was recorded as positive if participants had at least one symptom or an abnormal chest X-ray suggestive of tuberculosis, or a combination thereof. Sputum samples from participants who were screen-positive were tested by the Xpert MTB/RIF Ultra assay (first sample) and Mycobacteria Growth Indicator Tube culture (second sample), with optional HIV testing. Participants with a positive Mycobacterium tuberculosis complex culture were considered positive for bacteriologically confirmed pulmonary tuberculosis; when culture was not positive, participants with a positive Xpert MTB/RIF Ultra result with an abnormal chest X-ray suggestive of active tuberculosis and without current or previous tuberculosis were considered positive for bacteriologically confirmed pulmonary tuberculosis.FindingsBetween Aug 15, 2017, and July 28, 2019, 68 771 people were enumerated from 110 clusters, with 53 250 eligible to participate in the survey, of whom 35 191 (66·1%) participated. 9066 (25·8%) of 35 191 participants were screen-positive and 234 (0·7%) were identified as having bacteriologically confirmed pulmonary tuberculosis. Overall, the estimated prevalence of bacteriologically confirmed pulmonary tuberculosis was 852 cases (95% CI 679–1026) per 100 000 population; the prevalence was highest in people aged 35–44 years (1107 cases [95% CI 703–1511] per 100 000 population) and those aged 65 years or older (1104 cases [680–1528] per 100 000 population). The estimated prevalence was approximately 1·6 times higher in men than in women (1094 cases [95% CI 835–1352] per 100 000 population vs 675 cases [494–855] per 100 000 population). 135 (57·7%) of 234 participants with tuberculosis screened positive by chest X-ray only, 16 (6·8%) by symptoms only, and 82 (35·9%) by both. 55 (28·8%) of 191 participants with tuberculosis with known HIV status were HIV-positive.InterpretationPulmonary tuberculosis prevalence in this survey was high, especially in men. Despite the ongoing burden of HIV, many participants with tuberculosis in this survey did not have HIV. As more than half of the participants with tuberculosis had an abnormal chest X-ray without symptoms, prioritising chest X-ray screening could substantially increase case finding.FundingGlobal Fund, Bill & Melinda Gates Foundation, USAID.

Radiological and functional evidence of the bronchial spread of tuberculosis: an observational analysis

SummaryBackgroundDirect bronchial spread of tuberculosis was extensively described in pre-antibiotic human pathology literature but this description has been overlooked in the post-antibiotic era, in which most pathology data come from animal models that emphasise the granuloma. Modern techniques, such as [18F]2-fluoro-2-deoxy-D-glucose (FDG) PET-CT scans, might provide further insight. Our aim was to understand normal early tuberculosis resolution patterns on pulmonary PET-CT scans in treated patients with tuberculosis who were subsequently cured.MethodsIn this observational analysis, we analysed data from PredictTB, an ongoing, prospective, randomised clinical trial that examined sequential baseline and week 4 FDG-PET-CT scans from participants successfully treated (sputum culture negative 18 months after enrolment) for drug-susceptible pulmonary tuberculosis in South Africa and China. Participants who were aged 18–75 years, GeneXpert MTB/RIF positive for tuberculosis and negative for rifampicin resistance, had not yet started tuberculosis treatment, had not been treated for active tuberculosis within the previous 3 years, and met basic safety laboratory criteria were included and participants with diabetes, HIV infection, or with extrapulmonary tuberculosis including pleural tuberculosis were excluded. Scans were assessed by two readers for the location of tuberculosis lesions (eg, cavities and consolidations), bronchial thickening patterns, and changes from baseline to week 4 of treatment.FindingsAmong the first 124 participants (enrolled from June 22, 2017, to Sept 27, 2018) who were successfully treated, 161 primarily apical cavitary lesions were identified at baseline. Bronchial thickening and inflammation linking non-cavitary consolidative lesions to cavities were observed in 121 (98%) of 124 participants' baseline PET-CT scans. After 4 weeks of treatment, 21 (17%) of 124 participants had new or expanding lesions linked to cavities via bronchial inflammation that were not present at baseline, particularly participants with two or more cavities at baseline and participants from South Africa.InterpretationIn participants with pulmonary tuberculosis who were subsequently cured, the location of cavitary and non-cavitary lesions at baseline and new lesions at week 4 of treatment suggest a cavitary origin of disease and bronchial spread through the lungs. Bronchial spread from cavities might play a larger role in the spread of pulmonary tuberculosis than has been appreciated. Elucidating cavity lesion dynamics and Mycobacterium tuberculosis viability within cavities might better explain treatment outcomes and why some patients are cured and others relapse.FundingBill & Melinda Gates Foundation, European and Developing Countries Clinical Trials Partnership, China Ministry of Science and Technology, National Natural Science Foundation of China, and National Institutes of Health.TranslationsFor the Chinese, Afrikaans and Xhosa translations of the abstract see Supplementary Materials section.

Progress toward Developing Sensitive Non-Sputum-Based Tuberculosis Diagnostic Tests: the Promise of Urine Cell-Free DNA.

A highly accurate, non-sputum-based test for tuberculosis (TB) detection is a key priority for the field of TB diagnostics. A recent study in the Journal of Clinical Microbiology by Oreskovic and colleagues (J Clin Microbiol 59:e00074-21, 2021, https://doi.org/10.1128/JCM.00074-21) reports the performance of an optimized urine cell-free DNA (cfDNA) test using sequence-specific purification combined with short-target PCR to improve the accuracy of TB detection. Their retrospective clinical study utilized frozen urine samples (n = 73) from study participants diagnosed with active pulmonary TB in South Africa and compared results to non-TB patients in South Africa and the United States in an early-phase validation study. Overall, this cfDNA technique detected TB with a sensitivity of 83.7% (95% CI: 71.0 to 91.5) and specificity of 100% (95% CI: 86.2 to 100), which meet the World Health Organization's published performance criteria. Sensitivity was 73.3% in people without HIV (95% CI: 48.1 to 89.1) and 76% in people with smear-negative TB (95% CI: 56.5 to 88.5). In this commentary, we discuss the results of this optimized urine TB cfDNA assay within the larger context of TB diagnostics and pose additional questions for further research.

Risk factors for recurrent tuberculosis after successful treatment in a high burden setting: a cohort study

BackgroundPeople successfully completing treatment for tuberculosis remain at elevated risk for recurrent disease, either from relapse or reinfection. Identifying risk factors for recurrent tuberculosis may help target post-tuberculosis screening and care.MethodsWe enrolled 500 patients with smear-positive pulmonary tuberculosis in South Africa and collected baseline data on demographics, clinical presentation and sputum mycobacterial cultures for 24-loci mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR) typing. We used routinely-collected administrative data to identify recurrent episodes of tuberculosis occurring over a median of six years after successful treatment completion.ResultsOf 500 patients initially enrolled, 333 (79%) successfully completed treatment for tuberculosis. During the follow-up period 35 patients with successful treatment (11%) experienced a bacteriologically confirmed tuberculosis recurrence. In our Cox proportional hazards model, a 3+ AFB sputum smear grade was significantly associated with recurrent tuberculosis with a hazard ratio of 3.33 (95% CI 1.44–7.7). The presence of polyclonal M. tuberculosis infection at baseline had a hazard ratio for recurrence of 1.96 (95% CI 0.86–4.48).ConclusionOur results indicate that AFB smear grade is independently associated with tuberculosis recurrence after successful treatment for an initial episode while the association between polyclonal M. tuberculosis infection and increased risk of recurrence appears possible.

Environmental Silica Dust Exposure and Pulmonary Tuberculosis in Johannesburg, South Africa.

Background: Occupational crystalline silica dust exposure is associated with an elevated risk of pulmonary tuberculosis (PTB). However, there is less evidence for an association with environmental silica dust exposure. Methods: A cross-sectional study of 310 participants was conducted in an exposed community living within 2 km of gold mine tailings and an unexposed population residing more than 10 km from the nearest gold mine tailing. Chest radiographs (n = 178) were read for PTB, past or current, by three readers. Results: Past or current PTB was radiologically identified in 14.4% (95%CI 9.2–21.8) in the exposed and 7.5% (95%CI 2.8–18.7) in the unexposed groups. Multivariate logistic regression models suggested that PTB prevalence was independently associated with exposure to second-hand smoke (OR = 8.13, 95%CI 1.16–57.22), a lower body mass index (OR = 0.88, 95%CI 0.80–0.98), previous diagnosis and treatment of PTB (OR = 8.98, 95%CI 1.98–40.34), and exposure to dust in the workplace from sand, construction, and/or mining industries (OR = 10.2, 95%CI 2.10–50.11). Conclusion: We found no association between PTB and environmental exposure to gold mine tailing dust. However, workplace silica dust exposure is a significant risk factor for PTB in South Africa, and PTB patients of working age should be screened for silica exposure.

Association between Health-Related Quality of Life and Medication Adherence in Pulmonary Tuberculosis in South Africa.

Background: Health-related quality of life (HRQOL) and adherence to treatment are two often inter-related concepts that have implications for patient management and care. Tuberculosis (TB) and its treatment present a major public health concern in South Africa. The study aimed to evaluate the association between HRQOL and adherence in TB patients in South Africa.Methods: Four self-reported HRQOL and one self-reported adherence measures were used in an observational longitudinal multicentre study during 6-month standard TB treatment. These included the generic Short-Form 12 items (SF-12) and European Quality of Life 5 dimensions 5 levels (EQ-5D-5L), the disease-specific St. George's Respiratory Questionnaire (SGRQ) and the condition-specific Hospital Anxiety and Depression Scale (HADS) for HRQOL. Adherence was measured by the Morisky Medication Adherence Scale 8 items (MMAS-8). The relationship between both concepts was examined in 131 patients using Spearman's rho correlations, and linear regression models.Results: HRQOL improved over 6-month TB treatment, whereas adherence mean scores stayed constant with participants attaining a medium average level. Around 76% of patients reported to be high adherers and 24% were reporting a medium or low adherence. Associations between HRQOL and adherence were mainly weak. High adherence at treatment start was positively related to improvements in anxiety and depression after 6-month treatment. The overall improvement in pain and discomfort, and psychosocial health aspects over treatment time was positively, but weakly associated with adherence at 6 months of treatment.Conclusion: A positive relationship exists between adherence and HRQOL in TB in a South African setting, but this relationship was very weak, most likely because HRQOL is affected by a number of different factors and not limited to effects of adherence. Therefore, management of TB patients should, besides adequate drug treatment, address the specific mental and psychosocial needs.

Does Elevation Play a Role in the Transmission of Pulmonary Tuberculosis in South Africa?

Pulmonary Tuberculosis is the number one killer in South Africa. Although this is helped spurred on by the HIV/AIDS co-epidemic. We explored the effect of elevation in Tuberculosis transmission and mortality. Landsat 8 imageries were downloaded through earth-explorer and processed in Arc map 10.3. LULC maps generated from the satellite images were used for land characterization of provinces in South Africa. 3D DEM in Arc scene was utilized in displaying the elevation dataset. Our findings on the aggregate data at the provincial level could not show the association between elevation and Tuberculosis transmission and mortality.

Clinical Predictors of Culture-confirmed Pulmonary Tuberculosis in Children in a High Tuberculosis and HIV Prevalence Area

The burden of childhood tuberculosis (TB) remains significant especially in areas of high HIV prevalence. Clinical diagnosis predominates, despite advances in molecular and microbiological diagnostics. The aim of this study is to identify clinical features associated with culture-confirmed pulmonary TB (PTB) in children. Children admitted to hospital were enrolled in a study of novel diagnostics for PTB in South Africa. Standardized clinical, radiological and microbiological data were collected. Definite TB was defined by culture of Mycobacterium tuberculosis from a respiratory specimen. Adjusted odds ratios for definite TB were calculated using a multivariate logistic regression model. Adjusted odds ratio (AOR) for definite TB increased with a history of fever for more than 1 week [AOR: 8.54, 95% confidence interval (CI): 2.37-30.74], with a chest radiograph (CXR) suggestive of PTB (AOR: 10.0, 95% CI: 3.22-31.2) and with a positive tuberculin skin test (TST; AOR: 64.4, 95% CI: 14.3-290.5). The likelihood ratio of having definite TB if 2 of these factors (CXR and TST) were present compared with having none of them was 17.7. Cough, household contact with TB, HIV status and wheezing were not significantly associated with definite TB. Prolonged fever, CXR suggestive of TB or a positive TST were predictive of definite TB and should be considered in composite scoring systems for TB diagnosis in high HIV prevalence settings. Other commonly associated symptoms were not associated with definite TB.

Nationwide and regional incidence of microbiologically confirmed pulmonary tuberculosis in South Africa, 2004–12: a time series analysis

South Africa has the highest incidence of tuberculosis in the world, largely resulting from a high population prevalence of HIV infection. We investigated the incidence of microbiologically confirmed pulmonary tuberculosis, and new cases of pulmonary tuberculosis registered for treatment, nationally and provincially in South Africa from 2004 to 2012, during which time there were changes in antiretroviral therapy (ART) coverage among individuals with HIV infection. We identified cases of microbiologically confirmed pulmonary tuberculosis from 2004 to 2012 from the National Health Laboratory Service Corporate Data Warehouse. New cases registered for treatment were identified from National Department of Health electronic registries. A time series analysis, using autoregressive models, was undertaken on incidence of microbiologically confirmed pulmonary disease nationally and provincially; this trend was also examined relative to ART coverage of adults with HIV infection. During the 9-year period, 3 523 371 cases of microbiologically confirmed pulmonary tuberculosis were recorded nationally. Annual incidence (per 100 000 population) increased from 650 (95% CI 648-652) in 2004 to 848 (845-850) in 2008, declining to 774 (771-776) by 2012 (9% decrease from 2008 to 2012). Incidence varied by age-group, sex, and province. There was an inverse association between incidence of microbiologically confirmed disease and ART coverage among HIV-infected individuals nationally and provincially. Trends in incidence of tuberculosis cases registered for treatment mirrored those of microbiologically confirmed cases nationally and provincially; however, incidence of microbiologically confirmed cases was consistently higher than cases registered for treatment nationally and in seven of nine provinces. Since its peak in 2008, the incidence of microbiologically confirmed pulmonary tuberculosis in South Africa had declined by 2012; this decline is associated with an increase in ART coverage. Future integration of registries for microbiologically confirmed cases and new cases registered for treatment would improve the assessment of the burden of pulmonary tuberculosis in South Africa. National Institute for Communicable Diseases: Division of the National Health Laboratory Service, South Africa.

Excess Mortality Associated with Influenza among Tuberculosis Deaths in South Africa, 1999-2009.

BackgroundPublished data on the interaction between influenza and pulmonary tuberculosis (PTB) are limited. We aimed to estimate the influenza-associated mortality among individuals with PTB in South Africa from 1999–2009.MethodsWe modelled the excess influenza-associated mortality by applying Poisson regression models to monthly PTB and non-tuberculosis respiratory deaths, using laboratory-confirmed influenza as a covariate.ResultsPTB deaths increased each winter, coinciding with influenza virus circulation. Among individuals of any age, mean annual influenza-associated PTB mortality rate was 164/100,000 person-years (n = 439). The rate of non-tuberculosis respiratory deaths was 27/100,000 (n = 1125) for HIV-infected and 5/100,000 (n = 2367) for HIV-uninfected individuals of all ages. Among individuals aged <65 years, influenza-associated PTB mortality risk was elevated compared to influenza-associated non-tuberculosis respiratory deaths in HIV-infected (relative risk (RR): 5.2; 95% CI: 4.6–5.9) and HIV-uninfected individuals (RR: 61.0; CI: 41.4–91.0). Among individuals aged ≥65 years, influenza-associated PTB mortality risk was elevated compared to influenza-associated non-tuberculosis respiratory deaths in HIV-uninfected individuals (RR: 13.0; 95% CI: 12.0–14.0).ConclusionWe observed an increased risk of influenza-associated mortality in persons with PTB compared to non-tuberculosis respiratory deaths. If confirmed in other settings, our findings may support recommendations for active inclusion of patients with TB for influenza vaccination and empiric influenza anti-viral treatment of patients with TB during influenza epidemics.

Influenza virus infection is associated with increased risk of death amongst patients hospitalized with confirmed pulmonary tuberculosis in South Africa, 2010-2011.

BackgroundData on the association between influenza and tuberculosis are limited. We describe the characteristics of patients with laboratory-confirmed tuberculosis, laboratory-confirmed influenza and tuberculosis-influenza co-infection.MethodsPatients hospitalized with severe respiratory illness (acute and chronic) were enrolled prospectively in four provinces in South Africa. Naso/oropharyngeal specimens were tested for influenza virus by real time reverse transcriptase polymerase chain reaction. Tuberculosis testing was conducted as part of clinical management.ResultsFrom June 2010 through December 2011, 8032 patients were enrolled and influenza testing was conducted on 7863 (98%). Influenza virus was detected in 765 (10%) patients. Among 2959 patients with tuberculosis and influenza results, 2227 (75%) were negative for both pathogens, 423 (14%) were positive for tuberculosis alone, 275 (9%) were positive for influenza alone and 34 (1%) had influenza and tuberculosis co-infection. On multivariable analysis amongst individuals with symptoms for ≥7 days, tuberculosis influenza co-infection was associated with increased risk of death, (adjusted relative risk ratio (aRRR) (6.1, 95% confidence interval (CI) 1.6-23.4), as compared to tuberculosis only infection. This association was not observed in individuals with symptoms for <7 days (aRRR.0.8, 95% CI 0.1-7.0).ConclusionTuberculosis and influenza co-infection compared to tuberculosis single infection was associated with increased risk of death in individuals with symptoms ≥7 days. The potential public health impact of influenza vaccination among persons with laboratory-confirmed tuberculosis should be explored.

Impact and cost of algorithms for the diagnosis of adults with pulmonary tuberculosis in South Africa

436 July 2013, Vol. 103, No. 7 SAMJ Impact and cost of algorithms for the diagnosis of adults with pulmonary tuberculosis in South Africa To the Editor: We wish to respond to the letter[1] commenting on our article ‘Diagnosing Xpert MTB/RIF-negative TB: Impact and cost of alternative algorithms for South Africa’.[2] The National TB Cost Model was established to assist the South African Department of Health in understanding both the costs and the impact of alternative algorithms for the diagnosis of adults with symptoms of pulmonary tuberculosis (PTB) presenting for ambulatory care, with impact measured as the number of drugsensitive and drug-resistant TB cases diagnosed and treated.[3] The analysis in the SAMJ[2] addressed one arm of this algorithm, that of patients with symptoms suggestive of PTB who are HIV-infected but have a negative Xpert MTB/RIF test. Patients who are unable to produce sputum for testing (often because of young age) or have symptoms of extrapulmonary TB (EPTB) are not included in the Xpert-based algorithm adopted in South Africa (SA)[4] and were therefore not included in our analysis of alternatives. We agree, however, that modelling the impact and cost of alternative algorithms for diagnosis of paediatric TB and EPTB will be essential in guiding policy decisions as these algorithms are further developed. Black[1] concludes that ‘testing large numbers of patients with a second GXP for a <3% positive rate is not economically prudent’, a strong statement that is not referenced or supported in the text of the letter. In fact, our analysis concluded that, given SA ’s TB diagnostic guideline to continue to investigate patients who are HIV-infected and Xpert-negative for PTB despite the low yield of TB cases, a cost saving could be achieved by implementing a second Xpert MTB/RIF test instead of the smear, chest X-ray, culture and Hain line-probe assay (for positive cultures) currently required. In addition to the money saved, the alternative algorithm using two Xpert tests could potentially increase the proportion of patients actually treated, with subsequent reductions in risk of transmission and improvements in treatment outcomes, as Xpert results are available much more rapidly than culture results. The TB diagnostic algorithm is a tool to assist those who diagnose TB most often in SA – nurses at primary healthcare clinics. Guidelines, including algorithms, are there to support good clinical practice, not to be implemented blindly. Our modelling analysis suggests that an algorithm for adult, ambulatory PTB that calls for a second Xpert test for those who are HIV-infected will be less costly and result in more patients on treatment than the current culture-based algorithm. Other algorithms must still be developed for EPTB, paediatric TB, and non-TB conditions with similar symptoms.

New treatments for Tuberculosis

Diacon et al report a promising advance in both the future management of tuberculosis (TB) and the future design of drug trials in this field.1 The authors undertook a prospective,...

Longitudinal Analysis of QuantiFERON-TB Gold In-Tube in Children with Adult Household Tuberculosis Contact in South Africa: A Prospective Cohort Study

BackgroundQuantiFERON-TB Gold In Tube (QFT-GIT) is a tool for detecting M. tuberculosis infection. However, interpretation and utility of serial QFT-GIT testing of pediatric tuberculosis (TB) contacts is not well understood. We compared TB prevalence between baseline and 6 months follow-up using QFT-GIT and tuberculin skin testing (TST) in children who were household contacts of adults with pulmonary TB in South Africa, and explored factors associated with QFT-GIT conversions and reversions.MethodProspective study with six month longitudinal follow-up.ResultsAmong 270 enrolled pediatric contacts, 196 (73%) underwent 6-month follow-up testing. The 6-month prevalence estimate of MTB infection in pediatric contacts increased significantly from a baseline of 29% (79/270, 95%CI [24–35]) to 38% (103/270, 95% CI [32–44], p<0.001) using QFT-GIT; prevalence increased from a baseline of 28% (71/254, 95%CI [23–34]) to 33% (88/263, 95%CI [21–32], p = 0.002) using TST. Prevalence estimates were influenced by thresholds for positivity for TST, but not for QFT-GIT. Among 134 children with a negative or indeterminate baseline QFT-GIT, 24 (18%) converted to positive at follow-up; conversion rates did not differ significantly when using more stringent thresholds to define QFT-GIT conversion. Older age >10 years (AOR 8.9 95%CI [1.1–72]) and baseline TST positivity ≥5 mm (AOR 5.2 95%CI [1.2–23]) were associated with QFT-GIT conversion. Among 62 children with a positive baseline QFT-GIT, 9 (15%) reverted to negative; female gender (AOR 18.5 95%CI [1.1–321]; p = 0.04] was associated with reversion, while children with baseline positive TST were less likely to have QFT-GIT reversion (AOR 0.01 95%CI [0.001–0.24]).ConclusionAmong pediatric contacts of adult household TB cases in South Africa, prevalence estimates of TB infection increased significantly from baseline to 6 months. Conversions and reversions occurred among pediatric TB contacts using QFT-GIT, but QFT-GIT conversion rates were less influenced by thresholds used for conversions than were TST conversion rates.

Use of a WHO-recommended algorithm to reduce mortality in seriously ill patients with HIV infection and smear-negative pulmonary tuberculosis in South Africa: an observational cohort study

In 2007, WHO released revised recommendations and an algorithm for the diagnosis and treatment of smear-negative pulmonary tuberculosis in seriously ill people living with HIV/AIDS. We aimed to assess the effect of the recommendations on clinical outcome in patients in South Africa. We enrolled seriously ill patients (aged ≥15 years) with HIV infection and suspected smear-negative pulmonary tuberculosis from three hospitals in KwaZulu-Natal, South Africa. Patients were consecutively enrolled into two cohorts: the first cohort was managed according to standard practice, and the second according to the WHO-recommended algorithm. The primary endpoints were rates of continued stay in hospital at 7 days after admission and survival at 8 weeks after admission. 338 patients were enrolled in the standard practice cohort between August, 2008, and February, 2009, and 187 were enrolled in the algorithm cohort between March, 2009, and December, 2009. 7 days after hospital admission, 27% (n=50) of patients in the algorithm cohort were still in hospital, compared with 38% (n=130) in the standard practice cohort (rate ratio 0·70, 95% CI 0·53-0·91; p=0·009). 8 weeks after admission, 83% (n=156) of patients in the algorithm cohort were alive, compared with 68% (n=230) in the standard practice cohort (1·23, 1·11-1·35; p=0·0001), with effect modified by hospital location. In seriously ill patients with HIV infection and suspected smear-negative pulmonary tuberculosis, early antituberculosis treatment according to the WHO algorithm could significantly reduce mortality in South Africa. US President's Emergency Plan for AIDS Relief.