Do the tuberculin skin test and the QuantiFERON-TB Gold in-tube test agree in detecting latent tuberculosis among high-risk contacts? A systematic review and meta-analysis

A prevalence study in Guadalajara, Mexico, comparing tuberculin skin test and QuantiFERON-TB Gold In-Tube

Background

Tuberculosis (TB) is a prevalent disease throughout the world. The extent of TB illness in childhood is not clear; recent data shows that 10–20% of the cases are found in children under 15 years old. In 2017, 1 million children developed the disease, of which 9% were co-infected with HIV.

Methods

A cross-sectional study that analyzed 48 children diagnosed with HIV-infection in Guadalajara, Mexico. The tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube test (QFT) were performed and compared to diagnose latent TB infection (LTBI).

Results

The average age was 9 years old (± 4), with an age range of 1–16 years; the 6-12-year-old group predominated with 50% of cases. 27 patients (56%) were male; 83% had received the BCG vaccination and 23% had a history of being contacts of TB cases. In the study, 40 patients (83%) were without immunosuppression; seven (15%) with moderate immunosuppression, and only one patient had severe immunodeficiency. Overall, 3 of the 48 children (6.2%) had a positive TST, while 8 out of 48 (16.6%) had a positive QFT. The concordance between the two tests was 89.6% (43/48) with Kappa = 0.5 (95% CI, 0.14–0.85).

Conclusions

The QFT test represents an opportunity in the diagnosis of LTBI, particularly in pediatric HIV- patients. This is the first study that compares the two tests (TST and QFT) in children with HIV-infection in Guadalajara, Mexico.

Meta-analysis of latent tuberculosis in healthcare workers in Iran: a retrospective review

BACKGROUND

Here we review the status of latent tuberculosis (LTB) in Iranian healthcare workers (HCWs).

METHODS

A literature search was conducted using keywords according to the Preferred Reporting Items for Systematic Review and Meta-Analyses instructions. Cross-sectional studies published from 1 January 2000 through 1 January 2019 were retrieved. Meta-analysis was performed using Comprehensive Meta-Analysis software using the random effects model, Cochran's Q and I2 tests. Publication bias was estimated by funnel plot and Egger's linear regression test.

RESULTS

Among 774 articles retrieved in the primary literature search, 21 studies met the eligibility criteria. No publication bias was observed among the included studies (p=0.07). The prevalence of LTB ranged from 7% to 63% in Iranian HCWs from different geographical areas. The overall combined prevalence of LTB among Iranian HCWs was 30.9% (95% confidence interval 24.2 to 38.5). Also, 52.4% of the included studies showed a significant correlation between occupation and LTB incidence (p<0.05).

CONCLUSIONS

The prevalence of LTB was high among Iranian HCWs. This requires developing comprehensive information databases and surveillance systems for detecting LTB among HCWs. It is also essential to periodically screen for LTB in HCWs to provide a timely diagnosis of the infection. It is recommended to perform a tuberculin skin test, a useful tool for screening and treatment of LTB, on an annual basis in HCWs.

Comparative efficacy and safety of wenxin granule combined with antiarrhythmic drugs for atrial fibrillation: A protocol for a systematic review and network meta-analysis

BACKGROUND

The combination of Chinese patent medicine Wenxin Granules (WXG) and antiarrhythmic drugs has been widely used in the treatment of atrial fibrillation (AF), but the results are controversial. This study will conduct a network meta-analysis (NMA) based on data from randomized controlled trials to evaluate the efficacy and safety of WXG combined with ADDs (amiodarone, metoprolol, propafenone, bisoprolol, or other antiarrhythmic drugs) in the treatment of AF, which will perform comparisons or rankings of efficacy among the currently available therapeutic schemes in order to provide evidence to determine the optimal threshold and treatment regimen to AF patients.

METHODS AND ANALYSIS

A comprehensive systematic literature search will be conducted in Cochrane Library, PubMed, Web of Science, EMBASE, Chinese Biomedical Literature Database (SinoMed), Chinese National Knowledge Infrastructure (CNKI), and WanFang database for randomized controlled trials about the WXG with ADDs. The NMA will be conducted following the PRISMA-NMA guidelines. Statistical analyses will be conducted by using Stata software (version 14.0) and RevMan software (version 5.3).

RESULTS

The results of this NMA will provide a high-quality evidence for the efficacy of WXG combined with ADDs in the treatment of AF, and a ranking of the therapeutic classes will also be presented.

CONCLUSION

The protocol will provide updated evidence for the application of WXG for AF.

Comparative Results of QuantiFERON-TB Gold In-Tube and QuantiFERON-TB Gold Plus Assays for Detection of Tuberculosis Infection in Clinical Samples

The QuantiFERON-TB Gold plus (QFT-Plus) assay, an interferon gamma (IFN-γ) release assay (IGRA), was recently introduced as the next version of the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay for diagnosing latent tuberculosis (TB). Whereas the QFT-GIT assay uses only one TB tube that induces a cell-mediated immune (CMI) response of CD4⁺ T cells, the QFT-Plus has an additional TB antigen 2 tube (TB2) for the CMI response of CD8⁺ T and CD4⁺ T cells, in addition to a TB antigen 1 (TB1) tube for the CMI response of CD4⁺ T cells only. We compared the results of the QFT-Plus and QFT-GIT assays as routine clinical tests for diagnosing TB. Samples from 220 patients referred for routine IGRA in various clinical departments were used. Correlations between IFN-γ levels in the QFT-GIT and QFT-Plus assays were strong and showed good agreement (kappa value = 0.69). Seven cases with positive QFT-GIT assay results and negative QFT-Plus assay results showed IFN-γ values near the cutoff value. However, 10 cases with active TB, recent TB, or immune problems showed discordance with the positive results only in the TB2 tube in QFT-Plus, unlike the negative results in TB1 and TB tubes. In these cases, IFN-γ levels in the TB2 tube were significantly higher than those in other tubes. This is the first study to compare these assays as routine IGRAs in the clinical setting. The QFT-Plus assay showed good agreement with the QFT-GIT assay and is presumably advantageous for patients with active TB, recent TB, and specific immune conditions involving CD8⁺ T-cell responses.

Effectiveness of interventions for reducing TB incidence in countries with low TB incidence: a systematic review of reviews

AIMS

What is the evidence base for the effectiveness of interventions to reduce tuberculosis (TB) incidence in countries which have low TB incidence?

METHODS

We conducted a systematic review of interventions for TB control and prevention relevant to low TB incidence settings (<10 cases per 100 000 population). Our analysis was stratified according to "direct" or "indirect" effects on TB incidence. Review quality was assessed using AMSTAR2 criteria. We summarised the strength of review level evidence for interventions as "sufficient", "tentative", "insufficient" or "no" using a framework based on the consistency of evidence within and between reviews.

RESULTS

We found sufficient review level evidence for direct effects on TB incidence/case prevention of vaccination and treatment of latent TB infection. We also found sufficient evidence of beneficial indirect effects attributable to drug susceptibility testing and adverse indirect effects (measured as sub-optimal treatment outcomes) in relation to use of standardised first-line drug regimens for isoniazid-resistant TB and intermittent dosing regimens. We found insufficient review level evidence for direct or indirect effects of interventions in other areas, including screening, adherence, multidrug-resistant TB, and healthcare-associated infection.

DISCUSSION

Our review has shown a need for stronger evidence to support expert opinion and country experience when formulating TB control policy.

Prevalence of Latent Mycobacterium Tuberculosis Infection (LTBI) in Saudi Arabia; Population based survey

BACKGROUND

The annual risk of tuberculosis infection (ARTI) data in Saudi Arabia has not been updated since 1993.

OBJECTIVES

To estimate the prevalence of latent TB infection (LTBI) and ARTI in a population-based sample in Saudi Arabia using Tuberculin skin test (TST) and QuantiFERON TB Gold in tube (QFT-GIT) test.

METHODS

A population-based cross sectional study was conducted between July 2010 and March 2013. Participants were randomly selected from the population served by the primary healthcare centers of the Ministry of National Guard Health Affairs in Riyadh, Jeddah, Alhassa and Dammam, Saudi Arabia.

RESULTS

A total of 1369 participants were included. The overall prevalence of LTBI was similar using TST and QFT-GIT (9.3% and 9.1% respectively, p=0.872) but stratified prevalence rates were variable in all sociodemographic groups except marital status. Additionally, the prevalence rates of LTBI using either test alone showed significant differences by several sociodemographic and behavioral characteristics. The overall ARTI was 0.36% using TST and 0.35% using QFT-GIT.

CONCLUSIONS

We are reporting much lower estimates for the prevalence of LTBI and the ARTI in a population-based sample in Saudi Arabia relative to the data that have been used for more than two decades.

Detection of latent tuberculosis infection among migrant farmworkers along the US-Mexico border

Background

Migrant farmworkers are among the highest-risk populations for latent TB infection (LTBI) in the United States with numerous barriers to healthcare access and increased vulnerability to infectious diseases. LTBI is usually diagnosed on the border using the tuberculin skin test (TST). QuantiFERON-TB Gold In-Tube (QFT-GIT) also measures immune response against specific Mycobacterium tuberculosis antigens. The objective of this study is to assess the comparability of TST and QFT-GIT to detect LTBI among migrant farmworkers on the border, as well as to examine the effects of various demographic and clinical factors on test positivity.

Methods

Participants were recruited using mobile clinics on the San Luis US-Mexico border and tested with QFT-GIT and TST. Demographic profiles and clinical histories were collected. Kappa coefficients assessed agreement between TST and QFT-GIT using various assay cutoffs. Logistic regression examined factors associated with positive TST or QFT-GIT results.

Results

Of 109 participants, 59 of 108 (55 %) were either TST (24/71, 34 %) or QFT-GIT (52/106, 50 %) positive. Concordance between TST and QFT-GIT was fair (71 % agreement, ĸ = 0.38, 95 % CI: 0.15, 0.61). Factors associated with LTBI positivity included smoking (OR = 1.26, 95 % CI–1.01–1.58) and diabetes/high blood sugar (OR = 0.70, 95 % CI = 0.51–0.98).

Discussion

Test concordance between the two tests was fair, with numerous discordant results observed. Greater proportion of positives detected using QFT-GIT may help avoid LTBI under-diagnosis. Assessment of LTBI status on the border provides evidence whether QFT-GIT should replace the TST in routine practice, as well as identifies risk factors for LTBI among migrant populations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1959-3) contains supplementary material, which is available to authorized users.

Trend of some Tuberculosis Indices in Iran during 25 yr Period (1990-2014)

BACKGROUND

Investigation of tuberculosis (TB)-specific indices including prevalence of TB, mortality of TB cases excluding HIV, HIV/TB mortality, incidence of TB (all forms), HIV/TB incidence as well as case detection and related trends is a crucial step in evaluation of program performance and strategies success. Besides, estimating the number and time of change points for TB incidence can help to detect effective factors in TB control. Therefore, the current study aimed to determine the trend of aforementioned indices in Iran during a 25 yr period (1990 to 2014).

METHODS

Data on trend of TB in Iran was extracted from WHO regional office reports during 1990-2014. For determining the trend of TB indices, Annual Percent Changes (APC) and Average Annual Percent Changes (AAPC) was estimated using segmented regression model.

RESULTS

AAPC (95% CI) for HIV/TB mortality and HIV/TB incidence were 11.5 (9.3, 13.6) and 14.8 (13.6, 16.1), respectively, which are sign of increasing trend during the period (P<0.05). Other indices showed significantly decreasing trend (P<0.05), except for case detection rate (P =0.803).

CONCLUSIONS

The incidence, prevalence, and death rates of TB had shown a decreasing trend in general population, regarded as a useful indicator of achievements of Millennium Development Goals (MDGs) and effectiveness of interventional programs. Increasing trend of incidence and mortality of TB in HIV infected patients, needs conducting more intervention strategies in health care programs.