Recurrent tuberculosis in HIV-infected patients in Rio de Janeiro, Brazil

Recurrent Pulmonary Tuberculosis in China, 2005 to 2021

Importance

Despite posing a significant challenge to global tuberculosis (TB) elimination efforts, recurrent TB remains understudied due to the challenges of long-term observation.

Objective

To investigate the burden of recurrent TB using data from patients with pulmonary TB (PTB) in China.

Design, Setting, and Participants

This retrospective cohort study included all bacteriologically confirmed or clinically diagnosed PTB cases reported to the Tuberculosis Information Management System with completed or successful treatment outcomes from January 1, 2005, to December 31, 2021. Data were analyzed from July 15, 2022, to October 28, 2023.

Exposures

Newly diagnosed PTB was classified into primary, hematogenous disseminated, or secondary PTB.

Main Outcomes and Measures

The primary outcome was the annual recurrence rate, stratified by disease classification, over the 17-year observation period. The recurrence rate for year n was calculated by dividing the number of patients with recurrent TB in year n by observed person-years in year n. The secondary outcome was the annual proportion of recurrent TB among reported cases and associated risk factors.

Results

Of 13 833 249 patients with TB reported to the Tuberculosis Information Management System, 10 482 271 with PTB met the inclusion criteria. Of these, 68.9% were male, 22.3% were 65 years or older, 89.6% were of Han ethnicity, and 68.4% were agricultural workers. A total of 413 936 patients experienced a recurrent TB episode after successful treatment, resulting in an overall recurrence rate of 0.47 (95% CI, 0.47-0.48) per 100 person-years. The recurrence rate for patients with primary PTB was 0.24 (95% CI, 0.22-0.26) per 100 person-years; for hematogenous disseminated PTB, 0.37 (95% CI, 0.36-0.38) per 100 person-years; and for secondary PTB, 0.48 (95% CI, 0.47-0.48) per 100 person-years. The cumulative proportion of recurrences within the first 2 years accounted for 48.9% of all recurrent cases. The proportion of recurrent cases among notified incident cases increased 1.9-fold from 4.7% in 2015 to 8.8% in 2021. Among other factors, ages 45 to 64 years (adjusted hazard ratio, 1.77 [95% CI, 1.65-1.89]) and having completed treatment (adjusted hazard ratio, 1.16 [95% CI, 1.14-1.18]) were identified as associated with recurrence.

Conclusions and Relevance

In this retrospective cohort study, the PTB recurrence rate was substantially higher than the incidence, and the proportion of recurrent cases increased. Almost half of the recurrence occurred within the first 2 years, suggesting that routine posttreatment follow-up may represent an important strategy for accelerating TB elimination.

Decreased IL-1 β Secretion as a Potential Predictor of Tuberculosis Recurrence in Individuals Diagnosed with HIV

Background: The mechanisms of the formation of immunological competence against tuberculosis (TB), and especially those associated with HIV co-infection, remain poorly understood. However, there is an urgent need for risk recurrence predictive biomarkers, as well as for predictors of successful treatment outcomes. The goal of the study was to identify possible immunological markers of TB recurrence in individuals with HIV/TB co-infection. Methods: The plasma levels of IFN-γ, TNF-α, IL-10, and IL-1β (cytokines which play important roles in the immune activation and protection against Mycobacterium tuberculosis) were measured using ELISA EIA-BEST kits. The cytokine concentrations were determined using a standard curve obtained with the standards provided by the manufacturer of each kit. Results: A total of 211 individuals were enrolled in the study as follows: 62 patients with HIV/TB co-infection, 52 with HIV monoinfection, 52 with TB monoinfection, and 45 healthy donors. Out of the 62 patients with HIV/TB, 75.8% (47) of patients were newly diagnosed with HIV and TB, and 24.2% (15) displayed recurrent TB and were newly diagnosed with HIV. Decreased levels of IFN-γ, TNF-α, and IL-10 were observed in patients with HIV/TB when compared with HIV and TB patients. However, there was no difference in IFN-γ, TNF-α, or IL-10 secretion between both HIV/TB groups. At the same time, an almost 4-fold decrease in Il-1β levels was detected in the HIV/TB group with TB recurrence when compared with the HIV/TB group (p = 0.0001); a 2.8-fold decrease when compared with HIV patients (p = 0.001); and a 2.2-fold decrease with newly diagnosed TB patients (p = 0.001). Conclusions: Significantly decreased Il-1β levels in HIV/TB patients' cohort with secondary TB indicate that this cytokine can be a potential biomarker of TB recurrence.

Silico-tuberculosis amidst COVID-19 pandemic: global scenario and Indian perspective

Inhalation of crystalline silica-rich dust particles can result in the deadly occupational lung disorder called silicosis. The risk of contracting tuberculosis (TB) and the potential for lung cancer increase due to silicosis. This review article aims to bring to light the state of silicosis and TB scenario in the world and India for evaluating hurdles in the present and future to achieve the elimination road map and assess these conditions in the backdrop of the COVID-19 pandemic. A patient with silicosis has a 2.8-2.9 times higher risk of developing pulmonary TB and 3.7 times that of extrapulmonary TB. Incidences of missed cases when TB was misdiagnosed with silicosis due to indifferent clinical manifestations of the two in the initial stages are not uncommon. The duration of silica exposure and silicosis severity are directly related to the propensity to develop TB. As per a study, an average gap of 7.6 years has been noticed in a South African population for silico-tuberculosis to develop post-silicosis. In a study done on mine workers at Jodhpur, Rajasthan, it was seen that there is no definitive relation between patients with silicosis and the possibility of having COVID-19. There is a significant need to integrate the Silicosis control program with the TB elimination program for the government. A few steps can include assessing the workplaces, periodic monitoring of the workers' health, active case surveillance, identification of hotspots, and introducing reforms to curb the spread of dust and particulate matter from industrialised areas be taken in this regard.

Long-term outcomes after tuberculosis for people with HIV in eastern Europe

BACKGROUND

Eastern Europe has a high burden of tuberculosis (TB)/HIV coinfection with high mortality shortly after TB diagnosis. This study assesses TB recurrence, mortality rates and causes of death among TB/HIV patients from Eastern Europe up to 11 years after TB diagnosis.

METHODS

A longitudinal cohort study of TB/HIV patients enrolled between 2011 and 2013 (at TB diagnosis) and followed-up until end of 2021. A competing risk regression was employed to assess rates of TB recurrence, with death as competing event. Kaplan-Meier estimates and a multivariable Cox-regression were used to assess long-term mortality and corresponding risk factors. The Coding Causes of Death in HIV (CoDe) methodology was used for adjudication of causes of death.

RESULTS

Three hundred and seventy-five TB/HIV patients were included. Fifty-three (14.1%) were later diagnosed with recurrent TB [incidence rate 3.1/100 person-years of follow-up (PYFU), 95% confidence interval (CI) 2.4-4.0] during a total follow-up time of 1713 PYFU. Twenty-three of 33 patients with data on drug-resistance (69.7%) had multidrug-resistant (MDR)-TB. More than half with recurrent TB ( n  = 30/53, 56.6%) died. Overall, 215 (57.3%) died during the follow-up period, corresponding to a mortality rate of 11.4/100 PYFU (95% CI 10.0-13.1). Almost half of those (48.8%) died of TB. The proportion of all TB-related deaths was highest in the first 6 ( n  = 49/71; 69%; P  < 0.0001) and 6-24 ( n  = 33/58; 56.9%; P  < 0.0001) months of follow-up, compared deaths beyond 24 months ( n  = 23/85; 26.7%).

CONCLUSION

TB recurrence and TB-related mortality rates in PWH in Eastern Europe are still concerningly high and continue to be a clinical and public health challenge.

Prevalence of and Factors Associated with Reoccurrence of Opportunistic Infections Among Adult HIV/AIDS Patients Attending the ART Clinic at Public Health Facilities in Arba Minch Town, Southern Ethiopia

Background

Opportunistic infections (OIs) in human immunodeficiency virus (HIV)-positive individuals are infections that are more frequent or more severe than normal because of HIV-mediated immunosuppression. When these OIs occur in acquired immune deficiency syndrome (AIDS) patients in the form of relapse or reinfection, they are said to be a reoccurrence of OI. This study will try to identify gaps in addressing the burden in the study area.

Methods

This cross-sectional study was conducted among 450 HIV/AIDS patients with previous OIs attending a public health facility in Arba Minch Town, Southern Ethiopia. This study was conducted from 5 April 2020 to 20 April 2020. Computer-generated simple random sampling was used to select the study participants. Analysis was performed using SPSS version 25 statistical software. Bivariate and multivariable logistic regression was used to identify factors associated with the reoccurrence of OIs. A P value of ≤0.05 was used to determine significant association. The results were reported as numerical figures, tables, and diagrams, based on the type of data.

Results

The mean ± standard deviation age of the 450 study participants was 34.3±8.47 years. Eighty patients (17.8%) had chronic disease. In total, 119 HIV/AIDS patients (26.4%) were diagnosed with reoccurrence of OIs. Pulmonary tuberculosis was the major reoccurring OI. Age, rural residence, chronic disease, baseline anti-retroviral therapy (ART) adherence, current hemoglobin level, and current cell differentiation-4 (CD4) count were factors significantly associated with reoccurrence.

Conclusion

Although the magnitude of reoccurrence of OIs was lower than in previous studies, efforts have to be continued among stakeholders to tackle factors associated with the reoccurrence of OIs.

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

BACKGROUND

People 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.

METHODS

We 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.

RESULTS

Of 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).

CONCLUSION

Our 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.

"Universal test and treat" program reduced TB incidence by 75% among a cohort of adults taking antiretroviral therapy (ART) in Gurage zone, South Ethiopia

BACKGROUND

Tuberculosis (TB) remains the leading cause of morbidity and mortality in peoples living with HIV and at least 25% of deaths are attributed to TB. Many countries implement the Universal Test and Treat (UTT) program for HIV, which is believed to reduce the incidence of TB. However, there are limited studies that evaluate the impact of UTT on TB incidence. Therefore, by recruiting a cohort of ART users in the "UTT" and "differed treatment" programs, we aim to measure the effect of the UTT program on TB incidence.

OBJECTIVE

To measure the effect of "UTT" program on TB incidence among a cohort of adults taking antiretroviral therapy (ART) in Gurage Zone, South Ethiopia.

METHODS

A retrospective cohort study was conducted through record review over 5 years (2014-2019) in public health facilities in Gurage Zone. Three hundred eighty-four records were randomly selected and reviewed using a standardized structured checklist. Data was entered using Epi Info™ Version 7 and analyzed by STATA. A generalized linear model with binomial link function was fitted to measure the adjusted incidence density/incidence rate ratio and to identify predictors of incidence difference between the two programs.

RESULTS

During the follow up period, 39 incident TB cases were identified with an overall incidence rate of 4.79/100 person-year (PY). TB incidence was significantly lower in the UTT cohort (IR = 2.10/100 PY) in comparison to the differed program cohort (IR = 6.23/100 PY). The adjusted incidence rate ratio (AIRR) of TB among patients enrolled in the UTT program was; 0.25 (95% CI = 0.08-0.70). Thus, there was a reduction of TB incidence by 75% in the UTT program compared to differed program. In addition, IPT (isoniazid preventive therapy) use (AIRR = 0.35 (95% CI = 0.22-0.48)), WHO Stage I and II (AIRR = 0.70 (95% CI = 0.61-0.94)) and higher base line CD4 count (AIRR = 0.96 (95% CI = .94-0.99)) significantly reduced the incidence of TB. However, treatment failure increase the incidence (AIRR = 5.8 (95% CI = 1.93-8.46)).

CONCLUSION

TB incidence was significantly reduced by 75% after UTT. Therefore, intervention to further reduce the incidence has to focus on strengthening UTT program and IPT.

Trend analysis of tuberculosis case notifications with scale-up of antiretroviral therapy and roll-out of isoniazid preventive therapy in Zimbabwe, 2000-2018

OBJECTIVES

Antiretroviral therapy (ART) and isoniazid preventive therapy (IPT) are known to have a tuberculosis (TB) protective effect at the individual level among people living with HIV (PLHIV). In Zimbabwe where TB is driven by HIV infection, we have assessed whether there is a population-level association between IPT and ART scale-up and annual TB case notification rates (CNRs) from 2000 to 2018.

DESIGN

Ecological study using aggregate national data.

SETTING

Annual aggregate national data on TB case notification rates (stratified by TB category and type of disease), numbers (and proportions) of PLHIV in ART care and of these, numbers (and proportions) ever commenced on IPT.

RESULTS

ART coverage in the public sector increased from <1% (8400 PLHIV) in 2004 to ~88% (>1.1 million PLHIV patients) by December 2018, while IPT coverage among PLHIV in ART care increased from <1% (98 PLHIV) in 2012 to ~33% (373 917 PLHIV) by December 2018. These HIV-related interventions were associated with significant declines in TB CNRs: between the highest CNR prior to national roll-out of ART (in 2004) to the lowest recorded CNR after national IPT roll-out from 2012, these were (1) for all TB case (510 to 173 cases/100 000 population; 66% decline, p<0.001); (2) for those with new TB (501 to 159 cases/100 000 population; 68% decline, p<0.001) and (3) for those with new clinically diagnosed PTB (284 to 63 cases/100 000 population; 77.8% decline, p<0.001).

CONCLUSIONS

This study shows the population-level impact of the continued scale-up of ART among PLHIV and the national roll-out of IPT among those in ART care in reducing TB, particularly clinically diagnosed TB which is largely associated with HIV. There are further opportunities for continued mitigation of TB with increasing coverage of ART and in particular IPT which still has a low coverage.

Tuberculosis recurrences and predictive factors in a vulnerable population in Catalonia

BACKGROUND

Patients with a history of tuberculosis (TB) have a high probability of recurrence because long-term cure is not always maintained in successfully treated patients. The aim of this study was to identify the probability of TB recurrence and its predictive factors in a cohort of socially vulnerable patients who completed treatment in the TB referral center in Catalonia, which acts as the center for patients with social and health problems.

METHODS

This retrospective open cohort study included all patients diagnosed with TB who were admitted and successfully treated in Serveis Clínics between 2000 and 2016 and who remained disease-free for a minimum of 1 year after treatment completion. We calculated the incidence density of TB recurrences per person-years of follow-up. We also estimated the cumulative incidence of TB recurrence at 1, 2, 5, and 10 years of follow-up. Bivariate analysis was conducted using Kaplan-Meier curves. Multivariate analysis was conducted using Cox regression. Hazard ratios (HR) were calculated with their 95% confidence intervals (95%CI).

RESULTS

There were 839 patients and 24 recurrences (2.9%), representing 0.49 per 100 person-years. The probability of a recurrence was 0.63% at 1 year of follow-up, 1.35% at 2 years, and 3.69% at 5 years. The multivariate analysis showed that the predictive factors of recurrence were age older than 34 years (aHR = 3.90; CI = 1.06-14.34 at age 35-45 years and aHR = 3.88; CI = 1.02-14.80 at age >45 years) and resistance to at least one anti-TB drug (aHR = 2.91; CI = 1.11-7.65).

CONCLUSIONS

Attention should be paid to socially vulnerable persons older than 34 years with a previous episode of resistant TB. Surveillance resources should be directed toward adequately treated patients who nevertheless have a high risk of recurrence.

Predictors of recurrent TB in sputum smear and culture positive adults: a prospective cohort study

Objective

To explore simple inexpensive non-culture based predictors of recurrent pulmonary tuberculosis (PTB).

Setting and study population

HIV-infected and uninfected adults with the first episode of smear positive, culture-confirmed pulmonary tuberculosis in a high tuberculosis burden country.

Design

A nested prospective cohort study of participants with pulmonary tuberculosis (PTB) presenting to a hospital out-patient clinic.

Results

A total of 630 TB culture confirmed participants were followed up for eighteen months of which 57 (9%) developed recurrent recurrent TB. On univariate analysis,4.7% low grade(1+) pre-treatment sputum smear participants developed recurrent tuberculosis Vs 8.8% with high grade(3+) smears (OR=0.31,95%CI: 0.10–0.93, p=0.037).On multivariate analysis: participants with extensive fibro-cavitation had a high risk of recurrent TB Vs minimal end of treatment fibro-cavitation (18%Vs12%, OR=2.3,95%CI:1.09–4.68, p=0.03). Weight gain with HIV infection was assosciated with a high risk of recurrent TB Vs weight gain with no HIV infection(18%Vs 6%, OR=6.8,95%CI:165–27.83, p=0.008) where as weight gain with a low pre-treatment high bacillary burden was assosciated with a low risk of recurrent TB Vs weight gain with a high pre-treatmentbacillary burden(6.5%Vs7.9%, OR=0.2,95%CI:0.05–0.79, p=0.02).

Conclusion

Extensive end of treatment pulmonary fibro-cavitation, high pre-treatment bacillary burden with no weight gain and HIV infection could be reliable predictors of recurrent tuberculosis.

Survival of patients with AIDS and co-infection with the tuberculosis bacillus in the South and Southeast regions of Brazil

The study investigates the survival of patients with co-infection AIDS-TB through a retrospective study of a cohort of individuals aged 13 or more and the diagnosis of AIDS reported in the years 1998-99 and following 10 years. Of the 2,091 AIDS cases, 517 (24.7%) had positive diagnosis for tuberculosis, and 379 (73.3%) were male. The risk among co-infected patients was 1,65 times the not co-infected. Have been compared the exposed and non-exposed through the Kaplan-Meier and Cox method. The variables associated with longer survival were: female gender (HR = 0.63), educational level ≥ eight years (HR = 0.52), CD4 diagnostic criteria (HR = 0.64); and shorter survival: age ≥ 60 years (HR = 2.33), no use of HAART (HR = 8.62), no investigation to Hepatitis B (HR = 2.44) and opportunistic infections ≥ two (HR = 1.97). The average survival rate, related to TB infection was 69 months for the Southeast region and 73 months for the South. AIDS and tuberculosis require monitoring and treatment adherence and they are markers of the quality of care and survival of patients in Brazil.

Vitamin A and D Deficiencies Associated With Incident Tuberculosis in HIV-Infected Patients Initiating Antiretroviral Therapy in Multinational Case-Cohort Study

INTRODUCTION

Numerous micronutrients have immunomodulatory roles that may influence risk of tuberculosis (TB), but the association between baseline micronutrient deficiencies and incident TB after antiretroviral therapy (ART) initiation in HIV-infected individuals is not well characterized.

METHODS

We conducted a case-cohort study (n = 332) within a randomized trial comparing 3 ART regimens in 1571 HIV treatment-naive adults from 9 countries. A subcohort of 30 patients was randomly selected from each country (n = 270). Cases (n = 77; main cohort = 62, random subcohort = 15) included patients diagnosed with TB by 96 weeks post-ART initiation. We determined pretreatment concentrations of vitamin A, carotenoids, vitamin B6, vitamin B12, vitamin D, vitamin E, and selenium. We measured associations between pretreatment micronutrient deficiencies and incident TB using Breslow-weighted Cox regression models.

RESULTS

Median pretreatment CD4 T-cell count was 170 cells/mm; 47.3% were women; and 53.6% Black. In multivariable models after adjusting for age, sex, country, treatment arm, previous TB, baseline CD4 count, HIV viral load, body mass index, and C-reactive protein, pretreatment deficiency in vitamin A (adjusted hazard ratio, aHR 5.33, 95% confidence interval, CI: 1.54 to 18.43) and vitamin D (aHR 3.66, 95% CI: 1.16 to 11.51) were associated with TB post-ART.

CONCLUSIONS

In a diverse cohort of HIV-infected adults from predominantly low- and middle-income countries, deficiencies in vitamin A and vitamin D at ART initiation were independently associated with increased risk of incident TB in the ensuing 96 weeks. Vitamin A and D may be important modifiable risk factors for TB in high-risk HIV-infected patients starting ART in resource-limited highly-TB-endemic settings.

The cursed duet today: Tuberculosis and HIV-coinfection

The tuberculosis (TB) and HIV syndemic continues to rage and are a major public health concern worldwide. This deadly association raises complexity and represent a significant barrier towards TB elimination. TB continues to be the leading cause of death amongst HIV-infected people. This paper reports the challenges that lay ahead and outlines some of the current and future strategies that may be able to address this co-epidemic efficiently. Improved diagnostics, cheaper and more effective drugs, shorter treatment regimens for both drug-sensitive and drug-resistant TB are discussed. Also, special topics on drug interactions, TB-IRIS and TB relapse are also described. Notwithstanding the defeats and meagre investments, diagnosis and management of the two diseases have seen significant and unexpected improvements of late. On the HIV side, expansion of ART coverage, development of new updated guidelines aimed at the universal treatment of those infected, and the increasing availability of newer, more efficacious and less toxic drugs are an essential element to controlling the two epidemics. On the TB side, diagnosis of MDR-TB is becoming easier and faster thanks to the new PCR-based technologies, new anti-TB drugs active against both sensitive and resistant strains (i.e. bedaquiline and delamanid) have been developed and a few more are in the pipeline, new regimens (cheaper, shorter and/or more effective) have been introduced (such as the "Bangladesh regimen") or are being tested for MDR-TB and drug-sensitive-TB. However, still more resources will be required to implement an integrated approach, install new diagnostic tests, and develop simpler and shorter treatment regimens.

Factors associated with recurrent tuberculosis more than 12 months after treatment completion

SETTING

Even among persons who have completed a course of treatment for their first tuberculosis (TB) episode, patients with a history of TB are at higher risk for having TB.

OBJECTIVE

To describe factors from the initial TB episode associated with recurrent TB among patients who completed treatment and remained free of TB for at least 12 months.

DESIGN

During 1993-2006, US TB cases stratified by birth origin were examined. Cox proportional hazards regression was used to assess the association of factors during the initial episode with recurrence at least 12 months after treatment completion.

RESULTS

Among 632 US-born patients, TB recurrence was associated with age 25-44 years (adjusted hazard ratio [aHR] 1.77, 99% confidence interval [CI] 1.02-3.09, attributable fraction [AF] 1-34%), substance use (aHR 1.57, 99%CI 1.23-2.02, AF 8-22%), and treatment supervised by health departments (aHR 1.42, 99%CI 1.03-1.97, AF 2-28%). Among 211 foreign-born patients, recurrence was associated with human immunodeficiency virus infection (aHR 2.24, 99%CI 1.27-3.98, AF 2-9%) and smear-positive TB (aHR 1.56, 99%CI 1.06-2.30, AF 3-33%).

CONCLUSION

Factors associated with recurrence differed by origin of birth, and might be useful for anticipating greater risk for recurrent TB among certain patients with a history of TB.

Tuberculosis and HIV co-infection-focus on the Asia-Pacific region

Tuberculosis (TB) is the leading opportunistic disease and cause of death in patients with HIV infection. In 2013 there were 1.1 million new TB/HIV co-infected cases globally, accounting for 12% of incident TB cases and 360,000 deaths. The Asia-Pacific region, which contributes more than a half of all TB cases worldwide, traditionally reports low TB/HIV co-infection rates. However, routine testing of TB patients for HIV infection is not universally implemented and the estimated prevalence of HIV in new TB cases increased to 6.3% in 2013. Although HIV infection rates have not seen the rapid rise observed in Sub-Saharan Africa, indications are that rates are increasing among specific high-risk groups. This paper reviews the risks of TB exposure and progression to disease, including the risk of TB recurrence, in this vulnerable population. There is urgency to scale up interventions such as intensified TB case-finding, isoniazid preventive therapy, and TB infection control, as well as HIV testing and improved access to antiretroviral treatment. Increased awareness and concerted action is required to reduce TB/HIV co-infection rates in the Asia-Pacific region and to improve the outcomes of people living with HIV.

Tuberculosis retreatment 'others' in comparison with classical retreatment cases; a retrospective cohort review

BACKGROUND

Many of the countries in sub-Saharan Africa are still largely dependent on microscopy as the mainstay for diagnosis of tuberculosis (TB) including patients with previous history of TB treatment. The available guidance in management of TB retreatment cases is focused on bacteriologically confirmed TB retreatment cases leaving out those classified as retreatment 'others'. Retreatment 'others' refer to all TB cases who were previously treated but with unknown outcome of that previous treatment or who have returned to treatment with bacteriologically negative pulmonary or extra-pulmonary TB. This study was conducted in 11 regional referral hospitals (RRHs) serving high burden TB districts in Uganda to determine the profile and treatment success of TB retreatment 'others' in comparison with the classical retreatment cases.

METHODS

A retrospective cohort review of routinely collected National TB and Leprosy Program (NTLP) facility data from 1 January to 31 December 2010. This study uses the term classical retreatment cases to refer to a combined group of bacteriologically confirmed relapse, return after failure and return after loss to follow-up cases as a distinct group from retreatment 'others'. Distribution of categorical characteristics were compared using Chi-squared test for difference between proportions. The log likelihood ratio test was used to assess the independent contribution of type of retreatment, human immunodeficiency virus (HIV) status, age group and sex to the models.

RESULTS

Of the 6244 TB cases registered at the study sites, 733 (11.7%) were retreatment cases. Retreatment 'others' constituted 45.5% of retreatment cases. Co-infection with HIV was higher among retreatment 'others' (70.9%) than classical retreatment cases (53.5%). Treatment was successful in 410 (56.2%) retreatment cases. Retreatment 'others' were associated with reduced odds of success (AOR = 0.44, 95% CI 0.22,0.88) compared to classical cases. Lost to follow up was the commonest adverse outcome (38% of adverse outcomes) in all retreatment cases. Type of retreatment case, HIV status, and age were independently associated with treatment success.

CONCLUSION

TB retreatment 'others' constitute a significant proportion of retreatment cases, with higher HIV prevalence and worse treatment success. There is need to review the diagnosis and management of retreatment 'others'.

TB screening among people living with HIV/AIDS in resource-limited settings

Tuberculosis (TB) continues to be the leading cause of morbidity and mortality among people living with HIV (PLHIV), making improved prevention and treatment of HIV-associated TB critical to ensuring long-term survival of PLHIV. TB screening among PLHIV is central to implementation of the World Health Organization's 3 I's interventions for reducing the impact of the TB and HIV syndemics. Effective TB screening will result in the identification of PLHIV with presumptive TB disease (ie, those with a positive symptom screen who require appropriate evaluation, including the use of diagnostic tools such as the Xpert MTB/RIF assay) and those eligible for isoniazid preventive therapy (ie, those who have a negative clinical symptom screen or who have a positive screen but are found not to have TB disease). Identification of PLHIV with presumptive TB also facilitates implementation of basic administrative measures for TB infection control, including fast tracking of coughing patients and separation from noncoughing PLHIV to reduce TB transmission. By contributing to the early diagnosis of TB disease among PLHIV, TB screening is also critical to facilitate early initiation of antiretroviral treatment among PLHIV diagnosed with TB disease who might not otherwise be eligible for antiretroviral treatment based on CD4 count or clinical staging. TB screening thus serves as a gateway for multiple TB/HIV interventions and is an integral part of routine clinical services for PLHIV at each clinic visit.

Incidence of HIV-associated tuberculosis among individuals taking combination antiretroviral therapy: a systematic review and meta-analysis

BACKGROUND

Knowledge of tuberculosis incidence and associated factors is required for the development and evaluation of strategies to reduce the burden of HIV-associated tuberculosis.

METHODS

Systematic literature review and meta-analysis of tuberculosis incidence rates among HIV-infected individuals taking combination antiretroviral therapy.

RESULTS

From PubMed, EMBASE and Global Index Medicus databases, 42 papers describing 43 cohorts (32 from high/intermediate and 11 from low tuberculosis burden settings) were included in the qualitative review and 33 in the quantitative review. Cohorts from high/intermediate burden settings were smaller in size, had lower median CD4 cell counts at study entry and fewer person-years of follow up. Tuberculosis incidence rates were higher in studies from Sub-Saharan Africa and from World Bank low/middle income countries. Tuberculosis incidence rates decreased with increasing CD4 count at study entry and duration on combination antiretroviral therapy. Summary estimates of tuberculosis incidence among individuals on combination antiretroviral therapy were higher for cohorts from high/intermediate burden settings compared to those from the low tuberculosis burden settings (4.17 per 100 person-years [95% Confidence Interval (CI) 3.39-5.14 per 100 person-years] vs. 0.4 per 100 person-years [95% CI 0.23-0.69 per 100 person-years]) with significant heterogeneity observed between the studies.

CONCLUSIONS

Tuberculosis incidence rates were high among individuals on combination antiretroviral therapy in high/intermediate burden settings. Interventions to prevent tuberculosis in this population should address geographical, socioeconomic and individual factors such as low CD4 counts and prior history of tuberculosis.

Tuberculosis recurrence in a high incidence setting for HIV and tuberculosis in Brazil

Background

To compare epidemiological data between recurrent cases after cure (RC), distinguishing relapse from reinfection, after dropout (RD) and new cases (NC) in an ambulatory setting in a TB-endemic country.

Methods

Records of patients who started treatment for pulmonary TB between 2004 and 2010 in a TB clinic were reviewed. Epidemiological data were analyzed. Spoligotyping and MIRU patterns were used to determine relapse or reinfection in 13 RC available.

Results

Of the eligible group (1449), 1060 were NC (73.2%), among the recurrent cases, 203 (14%) were RC and 186 (12.8%) were RD. Of RC, 171 (84.2%) occurred later than 6 months after a previous episode, 13 had available DNA, in 4 (30.7%) the disease was attributed to reinfection and in 9 (69.3%), to relapse. Comparing RC to NC, HIV (p < 0.0001) was independent risk factor for RC. When RC and RD were compared, alcohol abuse (p = 0.001) and treatment noncompliance (p = 0.006) were more frequent in RD.

Conclusions

HIV is the sole more important associated factor for RC. This finding points the need to improve the approach to manage TB in order to decrease the chance for exposure especially in vulnerable people with increased risk of developing disease and to improve DOTS strategy to deal with factors associated to treatment noncompliance.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0548-6) contains supplementary material, which is available to authorized users.

Survival of HIV patients with tuberculosis started on simultaneous or deferred HAART in the THRio cohort, Rio de Janeiro, Brazil

Background

The timing of highly active antiretroviral therapy (HAART) after a tuberculosis diagnosis in HIV-infected patients can affect clinical outcomes and survival. We compared survival after tuberculosis diagnosis in HIV-infected adults who initiated HAART and tuberculosis therapy simultaneously to those who delayed the start of HAART for at least two months.

Methods

The THRio cohort includes 17,983 patients receiving HIV care in 29 public clinics in Rio de Janeiro, Brazil. HAART-naïve patients at the time of a new TB diagnosis between September 2003 and June 2008 were included. Survival was measured in days from diagnosis of TB. We compared survival among patients who initiated HAART within 60 days of TB treatment (simultaneous – ST) to those who started HAART >60 days of TB treatment or never started (deferred – DT). Kaplan–Meier plots and Cox proportional hazards regression analyses were conducted.

Results

Of 947 patients diagnosed with TB, 572 (60%) were HAART naïve at the time of TB diagnosis; 135 were excluded because of missing CD4 count results. Among the remaining 437 TB patients, 56 (13%) died during follow-up: 25 (10%) among ST patients and 31 (16%) in DT group (p = 0.08). ST patients had lower median CD4 counts at TB diagnosis than DT patients (106 vs. 278, p < 0.001). Cox proportional hazards utilizing propensity score analysis showed that DT patients were more likely to die (adjusted HR = 1.89; 95% CI: 1.05–3.40; p = 0.03).

Conclusion

HAART administered simultaneously with TB therapy was associated with improved survival after TB diagnosis. HAART should be given to patients with HIV-related TB as soon as clinically feasible.

Data needs for evidence-based decisions: a tuberculosis modeler's 'wish list'

Infectious disease models are important tools for understanding epidemiology and supporting policy decisions for disease control. In the case of tuberculosis (TB), such models have informed our understanding and control strategies for over 40 years, but the primary assumptions of these models--and their most urgent data needs--remain obscure to many TB researchers and control officers. The structure and parameter values of TB models are informed by observational studies and experiments, but the evidence base in support of these models remains incomplete. Speaking from the perspective of infectious disease modelers addressing the broader TB research and control communities, we describe the basic structure common to most TB models and present a 'wish list' that would improve the evidence foundation upon which these models are built. As a comprehensive TB research agenda is formulated, we argue that the data needs of infectious disease models--our primary long-term decision-making tools--should figure prominently.

Ficolin-2 defends against virulent Mycobacteria tuberculosis infection in vivo, and its insufficiency is associated with infection in humans

Human ficolin-2 (ficolin-2/P35) is a lectin complement pathway activator that is present in normal human plasma and is associated with infectious diseases; however, little is known regarding the roles and mechanisms of ficolin-2 during Mycobacterium tuberculosis (Mtb) infection. Here, we describe our novel findings that the ficolin-2 serum levels of 107 pulmonary tuberculosis (TB) patients were much lower compared with 107 healthy controls. In vitro analysis showed that ficolin-2 bound to the virulent Mtb H37Rv strain much more strongly than to the non-virulent M. bovis BCG and M. smegmatis. Ficolin-2 bound to the surface glycolipid portion of H37Rv and blocked H37Rv infection in human lung A549 cells. Opsonophagocytosis was also promoted by ficolin-2. Importantly, we found that administration of exogenous ficolin-2 had a remarkable protective effect against virulent Mtb H37Rv infection in both C57BL/6J and BALB/c mice. Ficolin-A (a ficolin-2-like molecule in mouse) knockout mice exhibited increased susceptibility to H37Rv infection. We further demonstrated that ficolin-2 could defend against virulent Mtb H37Rv infection at least partially by activating JNK phosphorylation and stimulating the secretion of interferon (IFN)-γ, interleukin (IL)-17, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide (NO) production by macrophages. Our data provide a new immunotherapeutic strategy against TB based on the innate immune molecule ficolin-2 and indicate that ficolin-2 insufficiency is associated with higher susceptibility to infection in humans.

Human immunodeficiency virus-associated tuberculosis: update on prevention and treatment

Tuberculosis (TB) is the leading cause of opportunistic infection and mortality among HIV-infected persons. Screening for symptoms of TB in people with HIV infection, use of isoniazid preventive therapy for those with latent TB infection, earlier diagnosis and treatment of active TB disease, and early initiation of antiretroviral therapy are essential for controlling the spread of TB. Treatment of HIV-related TB is complicated by overlapping drug toxicities and drug-drug interactions between antiretroviral therapy and anti-TB therapy and risk for development of immune reconstitution inflammatory disease. This review provides an overview of the prevention and treatment of TB in HIV-infected persons.

[The Spanish AIDS Study Group and Spanish National AIDS Plan (GESIDA/Secretaría del Plan Nacional sobre el Sida) recommendations for the treatment of tuberculosis in HIV-infected individuals (Updated January 2013)]

This consensus document was prepared by an expert panel of the Grupo de Estudio de Sida (GESIDA [Spanish AIDS Study Group]) and the Plan Nacional sobre el Sida (PNS [Spanish National AIDS Plan]). The document updates current guidelines on the treatment of tuberculosis (TB) in HIV-infected individuals contained in the guidelines on the treatment of opportunistic infections published by GESIDA and PNS in 2008. The document aims to facilitate the management and treatment of HIV-infected patients with TB in Spain, and includes specific sections and recommendations on the treatment of drug-sensitive TB, multidrug-resistant TB, and extensively drug-resistant TB, in this population. The consensus guidelines also make recommendations on the treatment of HIV-infected patients with TB in special situations, such as chronic liver disease, pregnancy, kidney failure, and transplantation. Recommendations are made on the timing and initial regimens of antiretroviral therapy in patients with TB, and on immune reconstitution syndrome in HIV-infected patients with TB who are receiving antiretroviral therapy. The document does not cover the diagnosis of TB, diagnosis/treatment of latent TB, or treatment of TB in children. The quality of the evidence was evaluated and the recommendations graded using the approach of the Grading of Recommendations Assessment, Development and Evaluation Working Group.

The impact of HIV and ART on recurrent tuberculosis in a sub-Saharan setting

OBJECTIVE

To estimate the impact of antiretroviral therapy (ART) on the incidence of recurrent tuberculosis (TB) in an African population.

DESIGN

A long-term population cohort in Karonga District, northern Malawi.

METHODS

Patients who had completed treatment for laboratory-confirmed TB diagnosed since 1996 were visited annually to record vital status, ART use and screen for TB. Survival analysis estimated the effect of HIV/ART status at completion of treatment on mortality and recurrence. Analyses were stratified by time since treatment completion to estimate the effects on relapse (predominates during first year) and reinfection disease (predominates later).

RESULTS

Among 1133 index TB cases contributing 4353 person-years of follow-up, there were 307 deaths and 103 laboratory-confirmed recurrences (recurrence rate 4.6 per 100 person-years). Half the recurrences occurred in the first year since completing treatment. HIV infection increased the recurrence rate [rate ratio adjusted for age, sex, period and TB type 2.69, 95% confidence interval (CI) 1.69-4.26], but with less effect in the first year (adjusted rate ratio 1.71, 95% CI 0.87-3.35) than subsequently (adjusted rate ratio 4.2, 95% CI 2.16-8.15). Recurrence rates on ART were intermediate between those of HIV-negative individuals and HIV-positive individuals without ART. Compared with HIV-positive individuals without ART, the adjusted rate ratio was 0.74 (95% CI 0.27-2.06) in the first year, and 0.43 (95% CI 0.11-1.73) later.

CONCLUSION

The increased incidence of TB recurrence observed in HIV-positive patients appeared to be reduced by ART. The effects are mostly on later (likely reinfection) disease so the impact of ART on reducing recurrence will be highest in high TB incidence settings.

Retreatment tuberculosis in a South African community: the role of re-infection, HIV and antiretroviral treatment

BACKGROUND

Limited data exist on the impact of human immunodeficiency virus (HIV) or antiretroviral treatment (ART) on retreatment tuberculosis (TB).

METHODS

Retreatment TB episodes between 2001 and 2010 in a high HIV and TB burden community were linked to first-episode treatment outcomes, HIV status and ART use. Genotypic analysis of Mycobacterium tuberculosis isolates distinguished re-infection from reactivation TB.

RESULTS

A total of 2027 TB episodes occurred in 1755 adults: 564 were retreatment cases. New patients who interrupted or failed initial treatment, were HIV-positive or were not on ART more frequently developed retreatment TB (respectively P < 0.001, P = 0.01 and P = 0.02). Time intervals between successive diagnoses were shorter in patients who interrupted/failed treatment compared to those with favourable initial treatment outcomes (P < 0.001), but did not vary by HIV status or ART use. Genotypic data were available for 40 successive diagnoses, of which 19 had matching M. tuberculosis strains. Matching strains were associated with HIV-negative status (P < 0.001), treatment interruption/failure (P = 0.04) and shorter intervals between diagnoses (P = 0.02). HIV-positive patients and patients on ART were more likely to have non-matched strains (P = 0.01 and P = 0.03).

CONCLUSION

Among HIV-negative patients, retreatment TB was predominantly due to reactivation following poor initial treatment outcomes. In HIV-positive patients re-infection TB was more common, particularly among those on ART.

Recurrent tuberculosis risk among HIV-infected adults in Tanzania with prior active tuberculosis

BACKGROUND

Active tuberculosis is common among human immunodeficiency virus (HIV)-infected persons living in tuberculosis-endemic areas, but the hazard of subsequent tuberculosis disease has not been quantified in a single prospective cohort.

METHODS

Among HIV-infected, BCG-immunized adults with CD4 counts ≥200 cells/μL who received placebo in the DarDar tuberculosis vaccine trial in Tanzania, we compared the prospective risk of active tuberculosis between subjects who did and who did not report prior active tuberculosis. All subjects with a positive tuberculin skin test without prior active tuberculosis were offered isoniazid preventive treatment. Definite or probable tuberculosis was diagnosed during active follow-up using rigorous published criteria.

RESULTS

We diagnosed 52 cases of definite and 92 cases of definite/probable tuberculosis among 979 subjects during a median follow-up of 3.2 years. Among the 80 subjects who reported prior active tuberculosis, 11 (13.8%) subsequently developed definite tuberculosis and 17 (21.3%) developed definite/probable tuberculosis, compared with 41 (4.6%) and 75 (8.3%), respectively, of 899 subjects without prior active tuberculosis (definite tuberculosis risk ratio [RR], 3.01; 95% confidence interval [CI], 1.61-5.63, P < .001; definite/probable tuberculosis RR, 2.55; 95% CI, 1.59-4.09, P < .001). In a Cox regression model adjusting for age, CD4 count, and isoniazid receipt, subjects with prior active tuberculosis had substantially greater hazard of subsequent definite tuberculosis (hazard radio [HR], 3.69; 95% CI, 1.79-7.63, P < .001) and definite/probable tuberculosis (HR, 2.78; 95% CI, 1.58-4.87, P < .001).

CONCLUSIONS

Compared to subjects without prior tuberculosis, the hazard of active tuberculosis is increased 3-fold among HIV-infected adults with prior active tuberculosis. Clinical Trials Registration. NCT0052195.

An updated systematic review and meta-analysis on the treatment of active tuberculosis in patients with HIV infection

BACKGROUND

Human immunodeficiency virus (HIV) infection increases the risk of poor outcomes in active tuberculosis. We updated a systematic review and meta-analysis assessing the effects of duration of rifamycins, schedule of dosing, and antiretroviral therapy (ART) on failure, relapse, death during treatment, and acquired drug resistance (ADR) in patients with HIV and active tuberculosis.

METHODS

We searched for randomized control trials (RCTs) and observational studies published between January 2008 and November 2011. We pooled risk differences (RD) from RCTs comparing rifampin for ≥9 months and 6 months. Within strata of the 3 treatment covariates, we calculated pooled risks and adjusted odds ratios (aORs) using outcomes from RCTs and observational studies.

RESULTS

After screening 2293 citations, 7 studies were added in the update. Risk of relapse was lowered with rifampin treatment for ≥9 months compared with 6 months (pooled RD = -9.1%; 95% CI, -16.5, -1.8). Odds of relapse were higher with shorter durations of rifamycins (aOR 2 vs ≥8 months = 5.0 [1.9, 13.2]; 6 vs ≥8 months = 2.4 [1.2, 5.0]) and in the absence of ART (aOR = 14.3, [2.1, 97.8]). Post hoc meta-regression restricted to arms with ART demonstrated no associations between rifamycin duration, dosing schedule, and outcomes.

CONCLUSIONS

In patients with HIV and active tuberculosis, ART reduces the risk of TB relapse. Use of rifamycins for ≥8 months and daily dosing in the intensive phase also improve TB treatment outcomes; however, a paucity of evidence makes their importance less clear for patients on ART. There is an urgent need to increase the number of coinfected patients receiving ART.

Modeling the dynamic relationship between HIV and the risk of drug-resistant tuberculosis

The emergence of highly drug-resistant tuberculosis (TB) and interactions between TB and HIV epidemics pose serious challenges for TB control. Previous researchers have presented several hypotheses for why HIV-coinfected TB patients may suffer an increased risk of drug-resistant TB (DRTB) compared to other TB patients. Although some studies have found a positive association between an individual's HIV status and his or her subsequent risk of multidrug-resistant TB (MDRTB), the observed individual-level relationship between HIV and DRTB varies substantially among settings. Here, we develop a modeling framework to explore the effect of HIV on the dynamics of DRTB. The model captures the acquisition of resistance to important classes of TB drugs, imposes fitness costs associated with resistance-conferring mutations, and allows for subsequent restoration of fitness because of compensatory mutations. Despite uncertainty in several key parameters, we demonstrate epidemic behavior that is robust over a range of assumptions. Whereas HIV facilitates the emergence of MDRTB within a community over several decades, HIV-seropositive individuals presenting with TB may, counterintuitively, be at lower risk of drug-resistant TB at early stages of the co-epidemic. This situation arises because many individuals with incident HIV infection will already harbor latent Mycobacterium tuberculosis infection acquired at an earlier time when drug resistance was less prevalent. We find that the rise of HIV can increase the prevalence of MDRTB within populations even as it lowers the average fitness of circulating MDRTB strains compared to similar populations unaffected by HIV. Preferential social mixing among individuals with similar HIV status and lower average CD4 counts among HIV-seropositive individuals further increase the expected burden of MDRTB. This model suggests that the individual-level association between HIV and drug-resistant forms of TB is dynamic, and therefore, cross-sectional studies that do not report a positive individual-level association will not provide assurance that HIV does not exacerbate the burden of resistant TB in the community.

The cost-effectiveness of routine tuberculosis screening with Xpert MTB/RIF prior to initiation of antiretroviral therapy: a model-based analysis

BACKGROUND

In settings with high tuberculosis (TB) prevalence, 15-30% of HIV-infected individuals initiating antiretroviral therapy (ART) have undiagnosed TB. Such patients are usually screened by symptoms and sputum smear, which have poor sensitivity.

OBJECTIVE

To project the clinical and economic outcomes of using Xpert MTB/RIF(Xpert), a rapid TB/rifampicin-resistance diagnostic, to screen individuals initiating ART.

DESIGN

We used a microsimulation model to evaluate the clinical impact and cost-effectiveness of alternative TB screening modalities - in all patients or only symptomatic patients - for hypothetical cohorts of individuals initiating ART in South Africa (mean CD4 cell count = 171 cells/μl; TB prevalence 22%). We simulated no active screening and four diagnostic strategies, smear microscopy (sensitivity 23%); smear and culture (sensitivity, 100%); one Xpert sample (sensitivity in smear-negative TB: 43%); two Xpert samples (sensitivity in smear-negative TB: 62%). Outcomes included projected life expectancy, lifetime costs (2010 US$), and incremental cost-effectiveness ratios (ICERs). Strategies with ICERs less than $7100 (South African gross domestic product per capita) were considered very cost-effective.

RESULTS

Compared with no screening, life expectancy in TB-infected patients increased by 1.6 months using smear in symptomatic patients and by 6.6 months with two Xpert samples in all patients. At 22% TB prevalence, the ICER of smear for all patients was $2800 per year of life saved (YLS), and of Xpert (two samples) for all patients was $5100/YLS. Strategies involving one Xpert sample or symptom screening were less efficient.

CONCLUSION

Model-based analysis suggests that screening all individuals initiating ART in South Africa with two Xpert samples is very cost-effective.

Antiretroviral treatment as prevention: impact of the 'test and treat' strategy on the tuberculosis epidemic

Antiretroviral therapy (ART) has been remarkably effective in ameliorating Human Immunodeficiency Virus (HIV)-associated morbidity and mortality. The rapid decline in viral load during ART also presents an opportunity to develop a “treatment as prevention” strategy in order to reduce HIV transmission at a population level. Modelling exercises have demonstrated that for this strategy to be effective, early initiation of ART with high coverage of the HIV-infected population will be required. The HIV epidemic has fueled a resurgence of tuberculosis (TB) particularly in sub-Saharan Africa and widespread early initiation of ART could also impact this epidemic via several mechanisms. The proportion of patients with low CD4 cell counts who are at high risk of TB disease from progression of both latent and new TB infection would be greatly reduced. Entry into a life-long ART program provides an ongoing opportunity for intensified TB case finding among the HIV-infected population. Regular screening for HIV infection also presents an opportunity for intensified TB case finding in the general population. The combined effect of reduced progression of infection to disease and intensified case finding could reduce the overall prevalence of infectious TB, thereby further decreasing TB transmission. In addition, decreasing prevalence of HIV infection would reduce the TB-susceptible pool within the population. The ‘test and treat’ strategy therefore has potential to reduce the TB risk at both an individual and a population level. In this paper we explore the expected “TB dividend” of wider access to ART and also explore the potential of the “test and treat” strategy to impact on TB transmission, particularly in the heavily burdened setting of sub-Saharan Africa.

Tuberculosis in antiretroviral treatment services in resource-limited settings: addressing the challenges of screening and diagnosis

The high burden of tuberculosis (TB) among patients accessing antiretroviral treatment (ART) services in resource-limited settings is a major cause of morbidity and mortality and is associated with nosocomial transmission risk. These risks are greatly compounded by multidrug-resistant disease. Screening and diagnosis of TB in this clinical setting is difficult. However, progress has been made in defining a high-sensitivity, standardized symptom screening tool that assesses a combination of symptoms, rather than relying on report of cough alone. Moreover, newly emerging diagnostic tools show great promise in providing more rapid diagnosis of TB, which is predominantly sputum smear–negative. These include culture-based systems, simplified versions of nucleic acid amplification tests (such as the Xpert MTB/RIF assay), and detection of lipoarabinomannan antigen in urine. In addition, new molecular diagnostics now permit rapid detection of drug resistance. Further development and implementation of these tools is vital to permit rapid and effective screening for TB in ART services, which is an essential component of patient care.

Antiretroviral therapy and the control of HIV-associated tuberculosis. Will ART do it?

The human immunodeficiency virus (HIV) associated tuberculosis (TB) epidemic remains an enormous challenge to TB control in countries with a high prevalence of HIV. In their 1999 article entitled 'Will DOTS do it?', De Cock and Chaisson questioned whether the World Health Organization's DOTS Strategy could control this epidemic. Data over the past 10 years have clearly shown that DOTS is insufficient as a single TB control intervention in such settings because it does not address the fundamental epidemiological interactions between TB and HIV. Immunodeficiency is a principal driver of this epidemic, and the solution must therefore include immune recovery using antiretroviral therapy (ART). Thus, in the era of global ART scale-up, we now ask the question, 'Will ART do it?' ART reduces the risk of TB by 67% (95%CI 61-73), halves TB recurrence rates, reduces mortality risk by 64-95% in cohorts and prolongs survival in patients with HIV-associated drug-resistant TB. However, the cumulative lifetime risk of TB in HIV-infected individuals is a function of time spent at various CD4-defined levels of risk, both before and during ART. Current initiation of ART at low CD4 cell counts (by which time much HIV-associated TB has already occurred) and low effective coverage greatly undermine the potential impact of ART at a population level. Thus, while ART has proven a critical intervention for case management of HIV-associated TB, much of its preventive potential for TB control is currently being squandered. Much earlier ART initiation with high coverage is required if ART is to substantially influence the incidence of TB.

Risk factors for tuberculosis after highly active antiretroviral therapy initiation in the United States and Canada: implications for tuberculosis screening

BACKGROUND

Screening for tuberculosis prior to highly active antiretroviral therapy (HAART) initiation is not routinely performed in low-incidence settings. Identifying factors associated with developing tuberculosis after HAART initiation could focus screening efforts.

METHODS

Sixteen cohorts in the United States and Canada contributed data on persons infected with human immunodeficiency virus (HIV) who initiated HAART December 1995-August 2009. Parametric survival models identified factors associated with tuberculosis occurrence.

RESULTS

Of 37845 persons in the study, 145 were diagnosed with tuberculosis after HAART initiation. Tuberculosis risk was highest in the first 3 months of HAART (20 cases; 215 cases per 100000 person-years; 95% confidence interval [CI]: 131-333 per 100000 person-years). In a multivariate Weibull proportional hazards model, baseline CD4+ lymphocyte count <200, black race, other nonwhite race, Hispanic ethnicity, and history of injection drug use were independently associated with tuberculosis risk. In addition, in a piece-wise Weibull model, increased baseline HIV-1 RNA was associated with increased tuberculosis risk in the first 3 months; male sex tended to be associated with increased risk.

CONCLUSIONS

Screening for active tuberculosis prior to HAART initiation should be targeted to persons with baseline CD4 <200 lymphocytes/mm³ or increased HIV-1 RNA, persons of nonwhite race or Hispanic ethnicity, history of injection drug use, and possibly male sex.

Harnessing the prevention benefits of antiretroviral therapy to address HIV and tuberculosis

After 30 years we are still struggling to address a devastating HIV pandemic in which over 25 million people have died. In 2010, an estimated 34 million people were living with HIV, around 70% of whom live in sub-Saharan Africa. Furthermore, in 2009 there were an estimated 1.2 million new HIV-associated TB cases, and tuberculosis (TB) accounted for 24% of HIV-related deaths. By the end of 2010, 6.6 million people were taking antiretroviral therapy (ART), around 42% of those in need as defined by the 2010 World Health Organization (WHO) guidelines. Despite this achievement, around 9 million people were eligible and still in need of treatment, and new infections (approximately 2.6 million in 2010 alone) continue to add to the future caseload. This combined with the international fiscal crisis has led to a growing concern regarding weakening of the international commitment to universal access and delivery of the Millennium Development Goals by 2015. The recently launched UNAIDS/WHO Treatment 2.0 platform calls for accelerated simplification of ART, in line with a public health approach, to achieve and sustain universal access to ART, including maximizing the HIV and TB preventive benefit of ART by treating people earlier, in line with WHO 2010 normative guidance. The potential individual and public health prevention benefits of using treatment in the prevention of HIV and TB enhance the value of the universal access pledge from a life-saving initiative, to a strategic investment aimed at ending the HIV epidemic. This review analyzes the gaps and summarizes the evidence regarding ART in the prevention of HIV and TB.

Antiretroviral program associated with reduction in untreated prevalent tuberculosis in a South African township

RATIONALE

In 2005, we reported high prevalence of untreated pulmonary tuberculosis (TB) in a South African community. Prevalent untreated TB is the main source of transmission. In settings with large burdens of human immunodeficiency virus (HIV) and TB, highly active antiretroviral therapy (HAART) may contribute to TB control.

OBJECTIVES

To assess the community-level impact of HAART on TB prevalence, we repeated a community-based TB prevalence cross-sectional survey in 2008 following HAART roll-out.

METHODS

A random 10% adult population sample was identified from the community. Participants provided two sputum specimens for acid-fast bacilli microscopy and TB culture. Oral transudate specimen was collected for anonymous HIV testing, linked to TB diagnosis. An interviewer-administered, structured questionnaire identified TB and HIV history and risk factors.

MEASUREMENTS AND MAIN RESULTS

In the 2008 survey, 1,250 adults participated (90% response rate); 306 (25%) tested HIV positive, of which 60 (20%) were receiving HAART. A total of 20 TB cases were identified (12 receiving TB treatment), representing a significant decline in prevalence from 3.2 to 1.6% (P = 0.02) between the surveys. TB prevalence in participants not infected with HIV was unchanged (P = 0.90). The decline occurred among participants not infected with HIV, decreasing from 9.2 to 3.6% in 2005 to 2008, respectively (P = 0.003). In participants infected with HIV, prevalence of treated TB declined from 4 to 2.3% (P = 0.06), and untreated TB prevalence from 5.2 to 1.3% (P = 0.02). The proportion of untreated TB in patients receiving HAART decreased significantly, from 22 to 0% (P < 0.001).

CONCLUSIONS

Prevalence of undiagnosed TB declined significantly over a period of increasing HAART availability. The decline was predominantly in individuals infected with HIV receiving HAART.

The HIV-associated tuberculosis epidemic--when will we act?

Despite policies, strategies, and guidelines, the epidemic of HIV-associated tuberculosis continues to rage, particularly in southern Africa. We focus our attention on the regions with the greatest burden of disease, especially sub-Saharan Africa, and concentrate on prevention of tuberculosis in people with HIV infection, a challenge that has been greatly neglected. We argue for a much more aggressive approach to early diagnosis and treatment of HIV infection in affected communities, and propose urgent assessment of frequent testing for HIV and early start of antiretroviral treatment (ART). This approach should result in short-term and long-term declines in tuberculosis incidence through individual immune reconstitution and reduced HIV transmission. Implementation of the 3Is policy (intensified tuberculosis case finding, infection control, and isoniazid preventive therapy) for prevention of HIV-associated tuberculosis, combined with earlier start of ART, will reduce the burden of tuberculosis in people with HIV infection and provide a safe clinical environment for delivery of ART. Some progress is being made in provision of HIV care to HIV-infected patients with tuberculosis, but too few receive co-trimoxazole prophylaxis and ART. We make practical recommendations about how to improve this situation. Early HIV diagnosis and treatment, the 3Is, and a comprehensive package of HIV care, in association with directly observed therapy, short-course (DOTS) for tuberculosis, form the basis of prevention and control of HIV-associated tuberculosis. This call to action recommends that both HIV and tuberculosis programmes exhort implementation of strategies that are known to be effective, and test innovative strategies that could work. The continuing HIV-associated tuberculosis epidemic needs bold but responsible action, without which the future will simply mirror the past.

Antiretroviral therapy for control of the HIV-associated tuberculosis epidemic in resource-limited settings

Great progress has been made over the past few years in HIV testing in patients who have tuberculosis (TB) and in the scale-up of antiretroviral therapy. More than 3 million people in resource-limited settings were estimated to have started antiretroviral therapy by the end of 2007 and 2 million of these were in sub-Saharan Africa. However, little is known about what impact this massive public health intervention will have on the HIV-associated TB epidemic or how antiretroviral therapy might be used to best effect TB control. This article provides an in-depth review of these issues.

Epidemiology of HIV-associated tuberculosis

PURPOSE OF REVIEW

We review literature concerning the epidemiology of HIV-associated tuberculosis (HIV-TB), focusing on articles published between 2007 and 2008.

RECENT FINDINGS

An estimated 1.37 million new cases of HIV-TB occurred in 2007, representing 15% of the total global burden of TB. In addition, an estimated 456 000 HIV-TB deaths accounted for 23% of global HIV/AIDS mortality. Sub-Saharan Africa is the worst affected region with 79% of the disease burden. The epicentre of the coepidemic lies in the south of the continent, with South Africa alone accounting for over one quarter of all cases. A critical overlap between HIV and the global multidrug-resistant TB epidemics is emerging. Although it is as yet unclear whether HIV is driving a disproportionate increase in multidrug-resistant TB cases at a population level, HIV has nevertheless been a potent risk factor for institutional outbreaks, especially in South Africa and eastern Europe. Increasing data have highlighted the risk of TB among HIV-infected healthcare workers in resource-limited settings. However, many studies also show the major benefits to be derived from antiretroviral therapy in high-income and low-income countries.

SUMMARY

HIV-TB remains a major challenge to global health that requires substantial increases in resource allocation and concerted international action.