Negative latent tuberculosis at time of incarceration: identifying a very high-risk group for infection

Cytokine/chemokine profiles in people with recent infection by Mycobacterium tuberculosis

Introduction

The risk of progression to tuberculosis disease is highest within the first year after M. tuberculosis infection (TBI). We hypothesize that people with newly acquired TBI have a unique cytokine/chemokine profile that could be used as a potential biomarker.

Methods

We evaluated socio-demographic variables and 18 cytokines/chemokines in plasma samples from a cohort of people deprived of liberty (PDL) in two Colombian prisons: 47 people diagnosed with pulmonary TB, 24 with new TBI, and 47 non-infected individuals. We performed a multinomial regression to identify the immune parameters that differentiate the groups.

Results

The concentration of immune parameters changed over time and was affected by the time of incarceration. The concentration of sCD14, IL-18 and IP-10 differed between individuals with new TBI and short and long times of incarceration. Among people with short incarceration, high concentrations of MIP-3α were associated with a higher risk of a new TBI, and higher concentrations of Eotaxin were associated with a lower risk of a new TBI. Higher concentrations of sCD14 and TNF-α were associated with a higher risk of TB disease, and higher concentrations of IL-18 and MCP-1 were associated with a lower risk of TB disease.

Conclusions

There were cytokines/chemokines associated with new TBI and TB disease. However, the concentration of immune mediators varies by the time of incarceration among people with new TBI. Further studies should evaluate the changes of these and other cytokines/chemokines over time to understand the immune mechanisms across the spectrum of TB.

Positive rate and risk factors of latent tuberculosis infection among persons living with HIV in Jiangsu Province, China

Objective

To analyze the latent tuberculosis infection (LTBI) among persons living with HIV(PLWH) in Jiangsu Province, to explore the factors affecting the positive rate of LTBI, and to take appropriate measures to control tuberculosis (TB) infection.

Methods

A cross-sectional study was conducted among PLWH in Jiangsu Province from June to July 2021. All PLWH in Jiangsu Province were used as the study population. Currently, the diagnosis of LTBI lacks a "gold standard" and can only be assisted by the immunological method. In this study, Tuberculin skin test (TST), ESAT6-CFP10 test (EC), and QuantiFERON-TB gold in-tube (QFT) were used to detect the positive rate of LTBI among PLWH and to analyze their risk factors.

Results

A total of 340 prisoners were included, 89.7% were male, the median age was 38 years [Interquartile Range (IQR):32-46 years], these patients were on Antiviral Therapy (ART), and median CD4 counts was 376 (IQR: 261-496), 103 (30.3%) were positive in at least one test, LTBI by TST was 16.5%, LTBI by EC was 15.9%, LTBI by QFT was 26.2%. Univariate analysis showed the results for TST, EC, and QFT were not affected by CD4 counts (p>0.05), and multivariate analysis showed that a history of incarceration was associated with an increased risk of positive TST (adjusted odds ratio [aOR]=1.98;95% CI,1.03-3.82), EC (aOR=2.65;95% CI,1.37-5.12) and QFT (aOR=2.01;95%CI,1.12-3.57), in addition, female gender was associated with increased risk of positive TST (aOR=3.66;95%CI,1.60-8.37) and EC (aOR=3.43;95%CI,1.46-8.07), and contact history of TB patients was associated with increased risk of TST (aOR= 2.54;95%CI,1.23-5.22) and QFT (aOR=2.03;95%CI,1.03-3.99), and ethnic minorities (aOR=0.26;95%CI,0.12-0.57), longer duration of incarceration was associated with an increased risk of positive QFT (aOR=1.12;95%CI,1.02-1.24). Conclusions Female gender, and ethnic minorities, history of incarceration, longer duration of incarceration, and contact history of TB patients are risk factors for LTBI among PLWH in Jiangsu Province, and attention should be paid to TB control in this population.

Demographic and Clinical Determinants of Tuberculosis and TB Recurrence: A Double-Edged Retrospective Study from Pakistan

Objective. TB recurrence is the second episode of TB after initial treatment bringing about an additional 7% load in TB burden intensified by 17.7% of multidrug-resistant recurrent cases. It is necessary to curb recurrence so that attempts to deal with active disease can be made more effective. This study aimed to characterize sociodemographic and clinical factors associated with recurrent TB in a high-burden setting. Methodology. A retrospective case-control study was carried out at two hospitals in Rawalpindi, Pakistan. TB patients and controls were included in the study. Sociodemographic and clinical data were collected by questionnaire from all subjects. Multivariate regression analysis was performed to determine factors associated with TB and TB recurrence respectively. Results. In our study cohort, factors significantly associated with TB were low BMI (OR: 0.961 (CI 0.954–0.968), $p<0.001$ ), female gender (OR: 2.065 (CI 1.922–2.219), $p<0.001$ ), being single/unmarried (OR: 1.214 (CI 1.109–1.328), $p=0.003$ ), middle-income status (OR: 1.935 (CI 1.616–2.323), $p<0.001$ ), smoking (OR: 1.567 (CI 1.435–1.710), $p<0.001$ ), and diabetes mellitus (OR: 1.142 (CI 1.017–1.278), $p=0.023$ ). TB recurrence constituted 11.2% of patients presenting to the hospital. Compared with the first episode of TB, cases with recurrence were more likely to be older (OR: 1.011 (CI 1.004–1.017), $p<0.001$ ), have disease awareness (OR: 1.906 (CI 1.486–2.437), $p<0.001$ ), smear positive (OR: 2.384 (CI 1.650–3.536), $p<0.001$ ), and be drug-resistant (OR: 5.615 (CI 4.265–7.386), $p<0.001$ ). Conclusion. In the present study cohort, low BMI, female gender, being single, middle-income status, being unemployed, smoking, and being diabetic came out to be the sociodemographic and clinical risk factors for TB. Further exploring the TB cases increasing age, drug resistance and smear positivity stood out to be the major sociodemographic and clinical factors of TB recurrence despite high disease awareness.

Number needed to screen for TB in clinical, structural or occupational risk groups

BACKGROUND: Screening for active TB using active case-finding (ACF) may reduce TB incidence, prevalence, and mortality; however, yield of ACF interventions varies substantially across populations. We systematically reviewed studies reporting on ACF to calculate the number needed to screen (NNS) for groups at high risk for TB.METHODS: We conducted a literature search for studies reporting ACF for adults published between November 2010 and February 2020. We determined active TB prevalence detected through various screening strategies and calculated crude NNS for - TB confirmed using culture or Xpert^® MTB/RIF, and weighted mean NNS stratified by screening strategy, risk group, and country-level TB incidence.RESULTS: We screened 27,223 abstracts; 90 studies were included (41 in low/moderate and 49 in medium/high TB incidence settings). High-risk groups included inpatients, outpatients, people living with diabetes (PLWD), migrants, prison inmates, persons experiencing homelessness (PEH), healthcare workers, and miners. Screening strategies included symptom-based screening, chest X-ray and Xpert testing. NNS varied widely across and within incidence settings based on risk groups and screening methods. Screening tools with higher sensitivity (e.g., Xpert, CXR) were associated with lower NNS estimates.CONCLUSIONS: NNS for ACF strategies varies substantially between adult risk groups. Specific interventions should be tailored based on local epidemiology and costs.

Incidence and Risk Factors Associated with Latent Tuberculosis Infection and Pulmonary Tuberculosis among People Deprived of Liberty in Colombian Prisons

People deprived of liberty (PDL) are at high risk of acquiring Mycobacterium tuberculosis infection (latent tuberculosis infection [LTBI]) and progressing to active tuberculosis (TB). We sought to determine the incidence rates and factors associated with LTBI and active TB in Colombian prisons. Using information of four cohort studies, we included 240 PDL with two-step tuberculin skin test (TST) negative and followed them to evaluate TST conversion, as well as, 2,134 PDL that were investigated to rule out active TB (1,305 among people with lower respiratory symptoms of any duration, and 829 among people without respiratory symptoms and screened for LTBI). Latent tuberculosis infection incidence rate was 2,402.88 cases per 100,000 person-months (95% CI 1,364.62-4,231.10) in PDL with short incarceration at baseline, and 419.66 cases per 100,000 person-months (95% CI 225.80-779.95) in individuals with long incarceration at baseline (who were enrolled for the follow after at least 1 year of incarceration). The TB incidence rate among PDL with lower respiratory symptoms was 146.53 cases/100,000 person-months, and among PDL without respiratory symptoms screened for LTBI the incidence rate was 19.49 cases/100,000 person-months. History of Bacillus Calmette-Guerin vaccination decreased the risk of acquiring LTBI among PDL who were recently incarcerated. Female sex, smoked drugs, and current cigarette smoking were associated with an increased risk of developing active TB. This study shows that PDL have high risk for LTBI and active TB. It is important to perform LTBI testing at admission to prison, as well as regular follow-up to control TB in prisons.

Incidence and prevalence of tuberculosis in incarcerated populations: a systematic review and meta-analysis

Background

Prisons are recognised as high-risk environments for tuberculosis, but there has been little systematic investigation of the global and regional incidence and prevalence of tuberculosis, and its determinants, in prisons. We did a systematic review and meta-analysis to assess the incidence and prevalence of tuberculosis in incarcerated populations by geographical region.

Methods

In this systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Knowledge, and the LILACS electronic database from Jan 1, 1980, to Nov 15, 2020, for cross-sectional and cohort studies reporting the incidence of Mycobacterium tuberculosis infection, incidence of tuberculosis, or prevalence of tuberculosis among incarcerated individuals in all geographical regions. We extracted data from individual studies, and calculated pooled estimates of incidence and prevalence through hierarchical Bayesian meta-regression modelling. We also did subgroup analyses by region. Incidence rate ratios between prisons and the general population were calculated by dividing the incidence of tuberculosis in prisons by WHO estimates of the national population-level incidence.

Findings

We identified 159 relevant studies; 11 investigated the incidence of M tuberculosis infection (n=16 318), 51 investigated the incidence of tuberculosis (n=1 858 323), and 106 investigated the prevalence of tuberculosis (n=6 727 513) in incarcerated populations. The overall pooled incidence of M tuberculosis infection among prisoners was 15·0 (95% credible interval [CrI] 3·8–41·6) per 100 person-years. The incidence of tuberculosis (per 100 000 person-years) among prisoners was highest in studies from the WHO African (2190 [95% CrI 810–4840] cases) and South-East Asia (1550 [240–5300] cases) regions and in South America (970 [460–1860] cases), and lowest in North America (30 [20–50] cases) and the WHO Eastern Mediterranean region (270 [50–880] cases). The prevalence of tuberculosis was greater than 1000 per 100 000 prisoners in all global regions except for North America and the Western Pacific, and highest in the WHO South-East Asia region (1810 [95% CrI 670–4000] cases per 100 000 prisoners). The incidence rate ratio between prisons and the general population was much higher in South America (26·9; 95% CrI 17·1–40·1) than in other regions, but was nevertheless higher than ten in the WHO African (12·6; 6·2–22·3), Eastern Mediterranean (15·6; 6·5–32·5), and South-East Asia (11·7; 4·1–27·1) regions.

Interpretation

Globally, people in prison are at high risk of contracting M tuberculosis infection and developing tuberculosis, with consistent disparities between prisons and the general population across regions. Tuberculosis control programmes should prioritise preventive interventions among incarcerated populations.

Funding

US National Institutes of Health.

Yield, Efficiency, and Costs of Mass Screening Algorithms for Tuberculosis in Brazilian Prisons

BACKGROUND

Tuberculosis (TB) is a major cause of morbidity and mortality among incarcerated populations globally. We performed mass TB screening in 3 prisons and assessed yield, efficiency, and costs associated with various screening algorithms.

METHODS

Between 2017 and 2018, inmates from 3 prisons in Brazil were screened for TB by symptom assessment, chest radiography, sputum testing by Xpert MTB/RIF fourth-generation assay, and culture. Chest radiographs were scored by an automated interpretation algorithm (Computer-Aided Detection for Tuberculosis [CAD4TB]) that was locally calibrated to establish a positivity threshold. Four diagnostic algorithms were evaluated. We assessed the yield (percentage of total cases found) and efficiency (prevalence among those screened) for each algorithm. We performed unit costing to estimate the costs of each screening or diagnostic test and calculated the cost per case detected for each algorithm.

RESULTS

We screened 5387 prisoners, of whom 214 (3.9%) were diagnosed with TB. Compared to other screening strategies initiated with chest radiography or symptoms, the trial of all participants with a single Xpert MTB/RIF sputum test detected 74% of all TB cases at a cost of US$249 per case diagnosed. Performing Xpert MTB/RIF screening tests only on those with symptoms had a similar cost per case diagnosed (US$255) but missed 35% more cases (73 vs 54) as screening all inmates.

CONCLUSIONS

In this prospective study in 3 prisons in a high TB burden country, we found that testing all inmates with sputum Xpert MTB/RIF was a sensitive approach, while remaining cost-efficient. These results support use of Xpert MTB/RIF for mass screening in TB-endemic prisons.

Increased incarceration rates drive growing tuberculosis burden in prisons and jeopardize overall tuberculosis control in Paraguay

Incarcerated populations are at high-risk to develop tuberculosis (TB), however their impact on the population-level tuberculosis epidemic has been scarcely studied. We aimed to describe the burden and trends of TB among incarcerated populations over time in Paraguay, its clinical and epidemiological differences and the population attributable fraction. This is an observational, descriptive study including all TB cases notified to the National TB control Program in Paraguay during the period 2009–2018. We also used case registries of prisoners diagnosed with tuberculosis from the Minister of Justice. The population attributable fraction of TB in the community due to incarcerated cases was estimated through Levin’s formula. The characteristics of TB cases in and outside of prison were compared as well as the characteristics of TB in prisons were modified over time. During 2009–2018, 2764 (9.7%) of the 28,534 TB reported cases in Paraguay occurred in prisons. The number of prisoners in Paraguay increased from 6258 in 2009 to 14,627 in 2018 (incarceration rate, 101 to 207 per 100,000 persons) while the number of TB cases among prisoners increased by 250% (n = 192 in 2009 versus n = 480 in 2018). The annual TB notification rate among male prisoners was 3218 and 3459 per 100,000 inmates in 2009 and 2018, respectively. The percentage of all TB cases occurring among prisoners increased from 7.1% in 2009 to 14.5% in 2018. The relative risk of TB in prisons compared to community was 70.3 (95% CI, 67.7–73.1); the overall population attributable risk was 9.5%. Among the 16 penitentiary centers in the country, two of them—Tacumbú (39.0%) and Ciudad del Este (23.3%)—represent two thirds of all TB cases in prisons. TB among inmates is predominantly concentrated in those 20–34 years old (77.3% of all), twice the percentage of cases for the same age group outside of prison. Our findings show that the TB epidemic in prisons represents one of the most important challenges for TB control in Paraguay, especially in the country’s largest cities. Appropriate TB control measures among incarcerated populations are needed and may have substantial impact on the overall TB burden in the country.

Primary Prophylaxis to Prevent Tuberculosis Infection in Prison Inmates: A Randomized, Double-Blind, Placebo-Controlled Trial

In many low- and middle-income countries, tuberculosis (TB) incidence in prisons is high, exposing incarcerated populations to an elevated risk of TB infection. We conducted a randomized, double-blind, placebo-controlled trial among HIV-negative male inmates of a high TB burden prison to determine whether isoniazid given twice weekly (900 mg) for 12 months prevents TB infection. The primary outcome was QuantiFERON-TB Gold in Plus (QFT) conversion to ≥ 0.35 international units per milliliter (IU/mL) at 6 months; secondary outcomes included alternative QFT thresholds (≥ 0.7, ≥ 2.0, and ≥ 4.0 IU/mL). In total, 467 participants were randomly assigned to intervention (N = 258) or control (N = 209). In an interim analysis of participants who had completed 6 months of follow-up (N = 170), QFT conversion occurred in 20.8% (19/91) and 21.5% (17/79) of participants in intervention and control arms (efficacy: 2.9%, P = 0.91), respectively. The trial was then stopped according to the trial protocol, and the remaining participants prematurely discontinued. In an analysis of secondary outcomes, the intervention arm had significantly lower rates of conversion at a cutoff of ≥ 2.0 IU/mL (efficacy: 82.6%, P < 0.01). In conclusion, 900 mg of isoniazid, administered twice a week, did not effectively prevent QFT conversion at a cutoff point ≥ 0.35 IU/mL in a trial of QFT-negative inmates. Higher QFT cutoffs are associated with sustained conversion and greater protection. Future clinical trials that evaluate protection for latent infection should use the highest cutoff than that recommended by the manufacturer.

Systematic analysis for the relationship between obesity and tuberculosis

OBJECTIVES

Underweight or low body mass index (BMI) is an established risk factor for active tuberculosis. Recent evidence, however, suggests that overweight is associated with lower incidence of tuberculosis. The objective of this systematic review and meta-analysis is to understand the relationship between obesity and tuberculosis and document the extent of association between the two conditions over the range of BMI from underweight to obesity.

METHODS

A comprehensive literature search was conducted to identify studies reporting prevalence of the different BMIs in patients with tuberculosis and controls. Thirty studies of adult humans reporting the incidence of tuberculosis at different weight categories were selected for inclusion for meta-analysis in the present study.

RESULTS

In tuberculosis, the prevalence of underweight was 3-fold higher than that in controls (P = 0.001) whereas the proportion of overweight and obesity was 2-fold lower (P = 0.001). One unit increase in BMI was associated with 2% reduction in tuberculosis incidence (P < 0.001). Adjusted odds ratio of tuberculosis was 4.96 (95% confidence interval: 4.87-5.05) in underweight and 0.26 in obesity.

CONCLUSION

This study further establishes low body weight as a risk factor for tuberculosis whilst overweight and obesity are associated with lower disease risk. Body weight can be considered as a prognostic indictor in the clinical course of tuberculosis.

Guards in Prisons: A Risk Group for Latent Tuberculosis Infection

To determine the prevalence and incidence of LTBI among prison guards and to the risk factors associated with infection. Two male prisons in Medellín and Itaguí, Colombia. A cohort study was conducted in adult prison guards that consented to participate. Exclusion criteria included: previous or current active TB, or conditions that preclude TST administration. We screened 194 guards and completed 155 TST administrations. The prevalence of LTBI was 55.8% in prison one, and 39.1% in prison two. The risk factors associated with LTBI diagnosis included drug use at least once in a lifetime (PR: 1.75; 95% CI 1.42-2.15) and male sex (PR: 2.16; 95% CI 1.01-4.62). The cumulative incidence of TST conversion over 6 months was 3.2%. All conversions occurred in prison 1. Our findings suggest an occupational risk for LTBI prevalence and incidence among guards (different prevalence and incidence according to the prison they work).

Active and latent tuberculosis among inmates in La Esperanza prison in Guaduas, Colombia

Introduction

Active tuberculosis (TB) and latent tuberculosis infection (LTBI) are a public health threat in prisons around the world. The objectives of the study were to estimate the prevalence of LTBI and TB as well as to investigate TB transmission inside one prison, in Colombia.

Methods

A Cross-sectional study was conducted in inmates who agreed to participate. Inmates with respiratory symptoms (RS) of any duration underwent to medical evaluation and three sputum samples were taken for smear microscopy and culture for TB diagnosis. Drug susceptibility was analyzed using BACTEC MGIT 960 and GenoType MTBDRplus. Molecular genotyping of Mycobacterium tuberculosis isolates was performed by 24-Locus MIRU-VNTR and spoligotyping. LTBI was evaluated according to the result of the tuberculin skin test (TST). Close contact investigation was conducted inside the prison for inmates that shared the cell with the index TB case.

Results

Among 301/2,020 (15%) inmates with RS of any duration, 8% were diagnosed with active TB. The prevalence of active TB was 1,026 cases/100,000 inmates. We isolated M. tuberculosis in 19/24 (79%) TB cases, 94.7% were susceptible to first line drugs and only one was monoresistant to isoniazid. The most prevalent sub-lineage was Haarlem (68.4%), followed by LAM (26.3%) and T superfamily (5.3%). 24-Locus MIRU-VNTR typing results alone or in combination with spoligotyping identified three clusters containing two isolates each. Two clusters corresponded to inmates that shared the same cell, but each one was located in different blocks of the prison. Inmates from the last cluster were in the same block in nearby cells. TST reading was performed in 95.6% inmates, and 67.6% had a positive reaction.

Conclusions

The prevalence of LTBI and TB was higher in prison than in the general population. Molecular genotyping suggests that TB in this prison is mainly caused by strains imported by inmates or endogenous reactivation.

Demographic, socio-economic and behavior as risk factors of tuberculosis in Malaysia: a systematic review of the literature

Background Tuberculosis (TB) is making a comeback and has remained one of the main causes of mortality among the list of infectious diseases in Malaysia. Objective To evaluate the burden and demographic, socio-economic and behavior as risk factors of TB among communities in Malaysia. Method A comprehensive search of Scopus, Sciencedirect, PubMed, DOAJ, CINAHL Plus, MyJournal, BIREME, BMC Public Health, Medline, CAB, EMBASE (Excerpta Medica dataBASE), and Web of Science (WoS) was undertaken from the articles published from 1st January 2008 to 31st December 2017 using medical subject heading (MeSH) key terms. Results Of 717 papers screened, 31 eligible studies met our inclusion criteria. Gender, age, marriage status, ethnicity, area of living, being in prison and immigrant were evaluated as demographic factors, while educational level, occupation and household income were evaluated as socio-economic factors. For behavioral factors, smoking, drug abuse, alcohol consumption and other lifestyle practices were evaluated. However, not all the studies were statistically significantly associated with these risk factors. Studies on household income were few and too small to permit a conclusion. We also did not find any study that investigated TB infection among sex workers. Conclusion Immigrant in high density settings may increase the progression of disease infection in Malaysia. The risk factors for the development of TB, specifically in a high-risk population, should be targeted through the implementation of specialized interventions. Further research into the role of indoor and outdoor physical environments is required to better understand the association between the physical environment and the social environment with TB infection.