BCG VACCINE PROTECTS AGAINST LATENT TB INFECTION AMONG CHILDREN IN CLOSE CONTACT WITH INFECTIOUS ADULT TB CASES

Author(s):  
Angeliki Syngelou
2020 ◽  
Vol 9 (10) ◽  
pp. 3224
Author(s):  
Angeliki Syggelou ◽  
Nikolaos Spyridis ◽  
Kyriaki Benetatou ◽  
Eleni Kourkouni ◽  
Georgia Kourlaba ◽  
...  

The Bacille Calmette–Guérin (BCG) vaccine has been shown to provide considerable protection against miliary or meningeal tuberculosis (TB), but whether it prevents other forms of disease remains controversial. Recent evidence has shown that the BCG vaccine also provides protection against latent TB infection (LTBI). The aim of the current study was to examine whether BCG has a protective role against LTBI among children in close contact with an adult index case in a low TB endemicity setting with the use of the QuantiFERON-TB Gold In-Tube test (QFT-GIT). A cross-sectional study was conducted over a 10-year period among children referred to our outpatient TB clinic with a history of close contact with an adult with pulmonary TB. All subjects had a QFT-GIT performed. In total, 207 children > 5 to 16 years of age with known recent exposure were enrolled. BCG-vaccinated subjects had a 59% lower risk of presenting with LTBI after close contact with an adult index case compared with unvaccinated subjects (OR = 0.41, 95% CI: 0.23–0.73, p = 0.002). After adjustment for possible confounders, the protective effect of prior BCG immunization was estimated at 68% (OR = 0.32, 95% CI: 0.15–0.66, p = 0.002). Other risk factors for LTBI included a history of migration (OR = 2.27, 95% CI: 1.13–4.53, p = 0.021) and transmission of infection to other exposed child contacts (OR = 4.62, 95% CI: 2.27–9.39, p = 0.001). We were able to determine a strong protective role of BCG vaccination among children older than 5 years, immunized at school entry, who had close contact with an adult infectious TB case.


2019 ◽  
Vol 39 (4) ◽  
pp. 256-265
Author(s):  
Erlina Burhan ◽  
Ririen Razika Ramdhani ◽  
Jamal Zaini

Background: Lung cancer and pulmonary tuberculosis (TB) are two major public health problems associated with significant morbidities and mortalities. The increased prevalence of active TB and latent TB reactivation in lung cancer patients and negative effect of pulmonary TB in lung cancer prognosis needed screening of lung cancer patients for latent TB infection (LTBI). This study aimed to determine the proportion of LTBI in lung cancer patients, their characteristics and the relationship between them. Methods: This study used cross-sectional design. Collecting sample used consecutive sampling of 86 newly diagnosed treatment-naive lung cancer patients from RSUP Persahabatan in 2015 to 2016. The presence of LTBI was determined by Quantiferon-TB Gold-In-Tube (QFT- GIT) after having Mycobacterium TB not detected result from Xpert MTB/RIF sputum test. Demographic characteristics and cancer-related factors associated with LTBI were investigated. Results: The results of latent TB tests were IGRA(+) 12.8%, IGRA(-) 68.6% and IGRA(I) 18.6%. Number of male patients with lung cancer with latent were 68.6%, as many as 55.8% were immunized with BCG, 4.6% had close contact with TB and 64% were using smoking. Most types of cancer were adenocarcinomas (77.9%) with advanced stage (82.6%) and general display status 2 (50%). The characteristics that show an association with IGRA results are the location of the cancer and the total lymphocyte count. Conclusion: The proportion of latent TB in lung cancer patients at the RSUP Persahabatan was 12.8%. The location of the cancer associated with the area of typical TB was related to latent TB, although it cannot be canceled. Results of IGRA(I) in lung cancer patients with low total lymphocyte counts prove IGRA sensitivity in the protection of latent TB infection in immunocompromised patients. (J Respir Indo. 2019; 39(4): 256-65)


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sivaporn Gatechompol ◽  
Weerakit Harnpariphan ◽  
Ruamthip Supanan ◽  
Gompol Suwanpimolkul ◽  
Jiratchaya Sophonphan ◽  
...  

Abstract Background Prisons are considered as major reservoirs for tuberculosis. Preventive therapy for latent TB infection (LTBI) is an adjunctive strategy to control TB. However, LTBI data in Thai prisoners is limited. This study assessed the prevalence of LTBI and feasibility of isoniazid preventive therapy (IPT). Methods A cross-sectional study was conducted among prisoners in Klong Prem Central Prison, Bangkok. Participants were screened for active TB by questionnaire and chest X-ray. LTBI was evaluated by Tuberculin skin test (TST) and QuantiFERON-TB Gold Plus (QFTP) among subgroup. Participants with positive TST or QFTP were considered to have LTBI. Participants with LTBI were offered IPT. Results From August 2018–November 2019, 1002 participants were analyzed. All participants were male with a median age of 38 (IQR 32–50) years. LTBI identified by either TST/QFTP was present in 466 (46.5%) participants. TST was positive in 359 (36%) participants. In the subgroup of 294 participants who had both TST and QFTP results, 181/294 (61.6%) tested positive by QFTP. Agreement between TST and QFTP was 55.1% (Kappa = 0.17). The risk factors associated with LTBI were previous incarceration (aOR 1.53, 95%CI, 1.16–2.01, p = 0.002), history of prior active TB (aOR 3.02, 95%CI, 1.74–5.24, p < 0.001) and duration of incarceration ≥10 years (aOR 1.86, 95%CI, 1.24–2.79, p = 0.003). Majority of LTBI participants (82%) agreed to take IPT. Three hundred and 56 (93%) participants completed treatment whereas 27 (7%) participants discontinued IPT due to the side effects of INH. Conclusion This is the first study to evaluate the prevalence of LTBI and feasibility of IPT among Thai prisoners. LTBI prevalence in male prisoners in Thailand is high. LTBI screening and treatment should be implemented together with other preventive components.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Birhan Alemnew ◽  
Soren T. Hoff ◽  
Tamrat Abebe ◽  
Markos Abebe ◽  
Abraham Aseffa ◽  
...  

Abstract Background Understanding immune mechanisms, particularly the role of innate immune markers during latent TB infection remains elusive. The main objective of this study was to evaluate mRNA gene expression patterns of toll-like receptors (TLRs) as correlates of immunity during latent TB infection and further infer their roles as potential diagnostic biomarkers. Methods Messenger RNA (mRNA) levels were analysed in a total of 64 samples collected from apparently healthy children and adolescents latently infected with tuberculosis (n = 32) or non-infected (n = 32). Relative expression in peripheral blood of selected genes encoding TLRs (TLR-1, TLR-2, TLR-4, TLR-6 and TLR-9) was determined with a quantitative real-time polymerase chain reaction (qRT-PCR) using specific primers and florescent labelled probes and a comparative threshold cycle method to define fold change. Data were analysed using Graph-Pad Prism 7.01 for Windows and a p-value less than 0.05 was considered statistically significant. Results An increased mean fold change in the relative expression of TLR-2 and TLR-6 mRNA was observed in LTBI groups relative to non-LTBI groups (p < 0.05), whereas a slight fold decrease was observed for TLR-1 gene. Conclusions An increased mRNA expression of TLR-2 and TLR-6 was observed in latently infected individuals relative to those non-infected, possibly indicating the roles these biomarkers play in sustenance of the steady state interaction between the dormant TB bacilli and host immunity.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Cui-lin Shi ◽  
Jian-ping Zhang ◽  
Ping Xu ◽  
Jin Li ◽  
Jie Shen ◽  
...  

Abstract Background Health care workers (HCWs) are at risk for occupationally acquired Mycobacterium tuberculosis infection and tuberculosis (TB) disease due to repeated exposure to workplace tubercle bacilli. To determine whether continual mycobacterial stimulation correlates with increased expression of inhibitory T cell receptors, here we compared PD-1 receptor expression on surfaces of circulating T cells between naïve (uninfected) HCWs and HCWs with latent TB infection (LTBI). Result Data collected from 133 medical workers who met study selection criteria were included in the final analysis. QuantiFERON-TB Gold In-​Tube (QFT-GIT) testing yielded positive results for 32 HCWs, for an overall LTBI rate of 24.1%. Multivariate analysis identified HCW length of service > 15 years as an independent risk factor for a positive QFT-GIT result. In addition, comparisons of blood T cell subgroup profiles between QFT- and QFT+ groups indicated QFT+ subjects possessed greater proportions of mature (TM), transitional memory (TTM) and effector memory (TEM) CD4+ T cell subgroups and lower proportions of naïve T cells (TN). Moreover, the QFT+ group percentage of CD8+ T cells with detectable surface PD-1 was significantly higher than the corresponding percentage for the QFT- group. Meanwhile, no statistical intergroup difference was observed in percentages of CD4+ T cells with detectible surface PD-1. Conclusions Our data demonstrated that upregulated PD-1 expression on circulating CD8+, but not CD4+ T cells, was associated with latent TB infection of HCWs. As compared to other hospitals, occupational TB infection risk in our hospital was substantially mitigated by implementation of multitiered infection control measures.


2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S289-S289
Author(s):  
Woosuck Suh ◽  
Jong-Hyun Kim ◽  
Ji Hyen Hwang ◽  
Sodam Lee ◽  
Kang-Hee Lee ◽  
...  

Abstract Background The Republic of Korea has the highest incidence rate of tuberculosis (TB) among members of the OECD, reported as 78.8/100,000 population in 2016. In response, a state-run intensive contact investigation for TB is being conducted. More effective TB control requires an epidemiologic emphasis on the diagnosis and treatment of latent TB infections in children and adolescents, compared with other age groups. Here we present an analysis of data from the childcare center and school contact investigation by the Korea Centers for Disease Control and Prevention (CDC) in 2013–2015. Methods Data collected from index patients included age, sex, occupation, disease status, results of AFB smear/culture, and chest x-ray. Data collected from contacts included age, sex, results of serial tuberculin skin test (TST), and chest x-ray. Congregate settings included childcare centers, kindergartens, elementary and secondary schools, and age groups were stratified as follows: 0–4 years, 5–12 years, and 13–18 years. TSTs were considered positive if induration ≥10 mm on the first test (TST1) or demonstrated an increase ≥6 mm over the induration of TST1 on repeat testing after 8 weeks (TST2). Results Of the 197,801 subjects with data collected, 173,998 were eligible and included in our analysis. TST1 results were available for 159,346 (91.6%) and when results were positive, induration was 10–14 mm in 7.6% and ≥15 mm in 1.5%. TST2 results were available for 119,797 (82.7%) of the 144,904 with negative TST1, and conversion rate was 9.0%. Altogether considering TST1 and TST2, 17.3% contacts had latent TB infections. Positive rates of TST significantly decreased with age: 20.3% in 0–4 years, 18.8% in 5–12 years, 17.1% in 13–18 years. Conclusion In this 3-year school-setting contact investigation, 17.3% contacts were diagnosed with latent TB infection, as demonstrated by TST reactions. Positive rates of TST significantly but mildly decreased with age. Disclosures All authors: No reported disclosures.


2018 ◽  
Vol 146 (16) ◽  
pp. 2102-2106 ◽  
Author(s):  
S. Anaraki ◽  
A.J. Bell ◽  
S. Perkins ◽  
S. Murphy ◽  
S. Dart ◽  
...  

AbstractFollowing an extensive contact tracing exercise at a school in a London borough with one of highest tuberculosis (TB) rates in England, we estimated the background prevalence of latent TB infection to be significantly less than the widely accepted 10%. We screened 271 pupils aged 14–15 years in two groups: 96 pupils in group 1 had significant exposure (>8 h/week in the same room) to a case of infectious TB and 175 in group 2 who had minimal exposure. In group 1, 26% were diagnosed with latent or active TB, compared to 6.3% in group 2. Risk factors for TB infection (e.g. previous exposure or link to high-prevalence communities) were analysed using a cohort study design. In the univariable analysis only being in contact group 1 was statistically significantly associated with being a case (OR 5.25, 95%, P < 0.001). In the multivariable model contact group 1 remained significantly associated with being a case (adjusted OR 4.40, P = 0.001). We concluded that the 6.3% yield of TB infection in contact group 2 is either similar to or higher than the background prevalence rate of latent TB infection (LTBI) in this high TB prevalence London borough. Other parts of England with lower TB prevalence are likely to have even lower LTBI rates.


2020 ◽  
pp. 153-171
Author(s):  
Ajit Lalvani ◽  
Clementine Fraser ◽  
Manish Pareek

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