Risk of infection and disease withMycobacterium tuberculosisamong children identified through prospective community-based contact screening in Indonesia

Prevalence and Associated Factors of Children Tuberculosis in Southeast Asia Countries: A Systematic Review

Southeast Asia (SEA) countries are characterised by a high burden of tuberculosis (TB). This research seeks to compile evidence of the prevalence and risk factors associated with TB among children in SEA countries. The searching of articles was conducted for four databases (PubMed, Scopus, Embase, and the Web of Science) published between 2013 and 2023 in the English language. The quality of articles was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Tool for Assessment of Risk Bias for Cross-Sectional studies. This research was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline. Eight studies were included in the systematic review. The prevalence of paediatric TB in SEA countries varies between 1.50% and 38.10%. Risk factors associated with the occurrence of TB in children include the nutritional status, the Bacillus Calmette-Guérin (BCG) vaccine status, close contact with TB patients, parental smoking behaviour, unhealthy living conditions, and socioeconomic determinants. The continued high prevalence of TB in several SEA countries, particularly among children, remains a significant public health concern. The various risk factors summarised can serve as a basis for implementing interventions aimed at reducing cases and preventing the transmission of TB among children.

Tuberculosis in 0-5-year-old children following TB contact investigations: a retrospective study in a low burden setting

Introduction

We assessed the risk of tuberculosis (TB), the management and the outcomes of 0-5-year-old children after TB contact investigations in a low-burden setting.

Method

All 0-5-year-old children who attended the TB clinic of Robert Debre Hospital, Paris, France, for a TB contact investigation between June 2016 and December 2019 were included in this retrospective study. The risk factors for TB were assessed using univariate and multivariate analyses.

Results

A total of 261 children were included. Forty-six (18%) had TB, including 37 latent tuberculosis infections (LTBIs) and 9 active TB diseases. The prevalence of TB was 21% among high-risk contacts, i.e., household or close contacts and regular or casual contacts. There was no TB among intermediate- or low-risk contacts (0/42). Living under the same roof with (OR: 19.8; 95% CI: 2.6-153), the BCG vaccine (OR: 3.2; 95% CI: 1.2-8.3), contact duration >40 h (OR: 7.6; 95% CI: 2.3-25.3) and sleeping in the room of the index case (OR: 3.9; 95% CI: 1.3-11.7) were independently associated with TB. The BCG vaccine was no longer associated when the analysis was restricted to interferon gamma release assay results. Among children without initial LTBI, antibiotic prophylaxis was not prescribed for 2-5-year-old children or for 32/36 (89%) of 0-2-year-old children who had intermediate- or low-risk contact. Overall, none of these children experienced TB.

Conclusion

In our low prevalence setting, the risk of TB in 0-5-year-old children following a household or close contact was high. Further studies are needed to better assess prophylaxis recommendations in intermediate or low risk contact.

Declining incidence rate of tuberculosis among close contacts in five years post-exposure: a systematic review and meta-analysis

BACKGROUND

Individuals in close contact with active pulmonary tuberculosis (TB) patients showed a high risk of recent infection and, once infected, higher risk of developing active TB in the following years post-exposure. But the peak time of active disease onset is unclear. This study aims to estimate post exposure TB incidence risk among close contacts to provide reference for clinical and public health strategies.

METHODS

We searched PubMed, Web of Science, and EMBASE for articles published until December 1, 2022. The incidence rates were quantitatively summarized by means of meta-analysis using the random-effect model.

RESULTS

Of the 5616 studies, 31 studies included in our analysis. For baseline close contacts results, the summarized prevalence of Mycobacterium tuberculosis (MTB) infection and active TB was found to be 46.30% (95% CI: 37.18%-55.41%) and 2.68% (95% CI: 2.02%-3.35%), respectively. During the follow-up, the 1-year, 2-year and 5-year cumulative incidence of TB in close contacts were 2.15% (95% CI: 1.51%-2.80%), 1.21% (95% CI: 0.93%-1.49%) and 1.11% (95% CI: 0.64%-1.58%), respectively. Individuals with a positive result of MTB infection testing at baseline showed significantly higher cumulative TB incidence as compared to those negatives (3.80% vs. 0.82%, p < 0.001).

CONCLUSIONS

Individuals with close contact to active pulmonary TB patients are bearing significant risk of developing active TB, particularly within the first-year post-exposure. Population with recent infections should be an important priority for active case finding and preventive intervention worldwide.

Tuberculosis contact-tracing results in childhood: a retrospective study in a tertiary-care children's hospital in Turkey

BACKGROUND

Smear-positive adults with tuberculosis are the main source of childhood tuberculosis. The evaluation of children exposed to tuberculosis and determination of the disease stages are the cornerstones of managing childhood tuberculosis.

AIM

To determine the frequency of tuberculous contact, latent tuberculosis infection and tuberculosis disease in children who were in contact with smear-positive adults.

METHODS

This is a single-centre, retrospective study. The medical records of children exposed to tuberculosis (<18 years old) between 2014 and 2018 were investigated. After diagnosing the index cases, the children were referred to the hospital. To identify the children in contact with adults with tuberculosis, a careful medical history, demographic features and physical examination, tuberculin skin test, postero-anterior and lateral chest radiographs, and, if necessary, chest computed tomography and microbiological tests were undertaken. The children's final diagnosis, treatment regimens and follow-up were documented. The sensitivity, specificity and positive and negative predictive values, tuberculin skin test and chest radiograph imaging were assessed and compared with computed tomography results.

RESULTS

A total of 150 paediatric patients were exposed to 88 index cases. These were fathers in 29.3% of cases and mothers in 10% of cases. Of the children, 131 (87.3%) were asymptomatic, and physical examination was normal in all children, apart from one who had respiratory symptoms. The tuberculin skin test results were positive in 60 (43%) patients and chest radiograph was abnormal in 100 (66%) children. Findings were consistent with tuberculosis in 34 (40%) of the 84 patients who underwent computed tomography. Fifty (38.5%) of the remaining children were defined as having been in contact with a case of tuberculosis, 41 (31.5%) had latent tuberculous infection and 39 (30%) had tuberculosis disease.

CONCLUSION

Pulmonary tuberculosis is asymptomatic in most children but with meticulous use of computed tomography it can be detected in asymptomatic children who have had close contact with tuberculosis.Abbreviation: AFB: acid-fast bacilli; AUC: area under the curve; BCG: bacillus Calmette-Guérin; CI: confidence interval; CT: computed tomography; CXR: chest radiograph; HIV: human immunodeficiency virus; ICD-10: International Classification of Diseases 10; LTBI: latent tuberculosis infection; MDR-TB: multi-drug-resistant tuberculosis; NPV: negative predictive value; PCR: polymerase chain reaction; PPV: positive predictive value; ROC: receiver operating characteristics; SD: standard deviation; TB: tuberculosis; TST: tuberculin skin test; XDR-TB: extensively drug-resistant tuberculosis.

Xpert MTB/RIF Ultra assay for tuberculosis disease and rifampicin resistance in children

BACKGROUND

Every year, an estimated one million children and young adolescents become ill with tuberculosis, and around 226,000 of those children die. Xpert MTB/RIF Ultra (Xpert Ultra) is a molecular World Health Organization (WHO)-recommended rapid diagnostic test that simultaneously detects Mycobacterium tuberculosis complex and rifampicin resistance. We previously published a Cochrane Review 'Xpert MTB/RIF and Xpert MTB/RIF Ultra assays for tuberculosis disease and rifampicin resistance in children'. The current review updates evidence on the diagnostic accuracy of Xpert Ultra in children presumed to have tuberculosis disease. Parts of this review update informed the 2022 WHO updated guidance on management of tuberculosis in children and adolescents.

OBJECTIVES

To assess the diagnostic accuracy of Xpert Ultra for detecting: pulmonary tuberculosis, tuberculous meningitis, lymph node tuberculosis, and rifampicin resistance, in children with presumed tuberculosis. Secondary objectives To investigate potential sources of heterogeneity in accuracy estimates. For detection of tuberculosis, we considered age, comorbidity (HIV, severe pneumonia, and severe malnutrition), and specimen type as potential sources. To summarize the frequency of Xpert Ultra trace results.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, three other databases, and three trial registers without language restrictions to 9 March 2021.

SELECTION CRITERIA

Cross-sectional and cohort studies and randomized trials that evaluated Xpert Ultra in HIV-positive and HIV-negative children under 15 years of age. We included ongoing studies that helped us address the review objectives. We included studies evaluating sputum, gastric, stool, or nasopharyngeal specimens (pulmonary tuberculosis), cerebrospinal fluid (tuberculous meningitis), and fine needle aspirate or surgical biopsy tissue (lymph node tuberculosis). For detecting tuberculosis, reference standards were microbiological (culture) or composite reference standard; for stool, we also included Xpert Ultra performed on a routine respiratory specimen. For detecting rifampicin resistance, reference standards were drug susceptibility testing or MTBDRplus.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and, using QUADAS-2, assessed methodological quality judging risk of bias separately for each target condition and reference standard. For each target condition, we used the bivariate model to estimate summary sensitivity and specificity with 95% confidence intervals (CIs). We stratified all analyses by type of reference standard. We summarized the frequency of Xpert Ultra trace results; trace represents detection of a very low quantity of Mycobacterium tuberculosis DNA. We assessed certainty of evidence using GRADE.

MAIN RESULTS

We identified 14 studies (11 new studies since the previous review). For detection of pulmonary tuberculosis, 335 data sets (25,937 participants) were available for analysis. We did not identify any studies that evaluated Xpert Ultra accuracy for tuberculous meningitis or lymph node tuberculosis. Three studies evaluated Xpert Ultra for detection of rifampicin resistance. Ten studies (71%) took place in countries with a high tuberculosis burden based on WHO classification. Overall, risk of bias was low. Detection of pulmonary tuberculosis Sputum, 5 studies Xpert Ultra summary sensitivity verified by culture was 75.3% (95% CI 64.3 to 83.8; 127 participants; high-certainty evidence), and specificity was 97.1% (95% CI 94.7 to 98.5; 1054 participants; high-certainty evidence). Gastric aspirate, 7 studies Xpert Ultra summary sensitivity verified by culture was 70.4% (95% CI 53.9 to 82.9; 120 participants; moderate-certainty evidence), and specificity was 94.1% (95% CI 84.8 to 97.8; 870 participants; moderate-certainty evidence). Stool, 6 studies Xpert Ultra summary sensitivity verified by culture was 56.1% (95% CI 39.1 to 71.7; 200 participants; moderate-certainty evidence), and specificity was 98.0% (95% CI 93.3 to 99.4; 1232 participants; high certainty-evidence). Nasopharyngeal aspirate, 4 studies Xpert Ultra summary sensitivity verified by culture was 43.7% (95% CI 26.7 to 62.2; 46 participants; very low-certainty evidence), and specificity was 97.5% (95% CI 93.6 to 99.0; 489 participants; high-certainty evidence). Xpert Ultra sensitivity was lower against a composite than a culture reference standard for all specimen types other than nasopharyngeal aspirate, while specificity was similar against both reference standards. Interpretation of results In theory, for a population of 1000 children: • where 100 have pulmonary tuberculosis in sputum (by culture): - 101 would be Xpert Ultra-positive, and of these, 26 (26%) would not have pulmonary tuberculosis (false positive); and - 899 would be Xpert Ultra-negative, and of these, 25 (3%) would have tuberculosis (false negative). • where 100 have pulmonary tuberculosis in gastric aspirate (by culture): - 123 would be Xpert Ultra-positive, and of these, 53 (43%) would not have pulmonary tuberculosis (false positive); and - 877 would be Xpert Ultra-negative, and of these, 30 (3%) would have tuberculosis (false negative). • where 100 have pulmonary tuberculosis in stool (by culture): - 74 would be Xpert Ultra-positive, and of these, 18 (24%) would not have pulmonary tuberculosis (false positive); and - 926 would be Xpert Ultra-negative, and of these, 44 (5%) would have tuberculosis (false negative). • where 100 have pulmonary tuberculosis in nasopharyngeal aspirate (by culture): - 66 would be Xpert Ultra-positive, and of these, 22 (33%) would not have pulmonary tuberculosis (false positive); and - 934 would be Xpert Ultra-negative, and of these, 56 (6%) would have tuberculosis (false negative). Detection of rifampicin resistance Xpert Ultra sensitivity was 100% (3 studies, 3 participants; very low-certainty evidence), and specificity range was 97% to 100% (3 studies, 128 participants; low-certainty evidence). Trace results Xpert Ultra trace results, regarded as positive in children by WHO standards, were common. Xpert Ultra specificity remained high in children, despite the frequency of trace results.

AUTHORS' CONCLUSIONS

We found Xpert Ultra sensitivity to vary by specimen type, with sputum having the highest sensitivity, followed by gastric aspirate and stool. Nasopharyngeal aspirate had the lowest sensitivity. Xpert Ultra specificity was high against both microbiological and composite reference standards. However, the evidence base is still limited, and findings may be imprecise and vary by study setting. Although we found Xpert Ultra accurate for detection of rifampicin resistance, results were based on a very small number of studies that included only three children with rifampicin resistance. Therefore, findings should be interpreted with caution. Our findings provide support for the use of Xpert Ultra as an initial rapid molecular diagnostic in children being evaluated for tuberculosis.

Assessment of Interferon Gamma-Induced Protein 10 mRNA Release Assay for Detection of Latent Tuberculosis Infection in Egyptian Pediatric Household Contacts

OBJECTIVES

Current diagnostic tests for tuberculosis (TB) in children living in low-endemic countries are limited by low specificity and the inability of the current tests to differentiate between active TB and latent TB infection (LTBI). This study aimed to evaluate the blood IP-10 mRNA expression level to detect LTBI in Egyptian pediatric household contacts (PHC).

METHODS

TB-specific IP-10 and IFN-γ mRNA levels were assessed by real-time quantitative PCR (RT-qPCR) in 72 Egyptian PHC of active pulmonary TB cases. All study participants were also assessed by Tuberculin Skin Test (TST) and Quantiferon gold in tube (QFN-GIT) assay.

RESULTS

IP-10 and IFN-γ mRNA expression levels were significantly higher in PHC with active TB or LTBI than TB negative (p < 0.0001). The level of IP-10 mRNA expression was significantly higher in PHC with active TB than LTBI (p = 0.0008). In contrast, there was no significant differences in the IFN-γ mRNA expression between PHC with active TB compared to LTBI (p = 0.49). The sensitivity and specificity of the IP-10 RT-qPCR were 94.2% and 95.2%, respectively, in PHC with active TB compared to 85.7% and 81.8% in PHC with LTBI. The negative and positive predictive values and accuracy of IP-10 RT-qPCR for distinguishing active TB from LTBI were 85.2%, 58.3%, and 72.6% respectively.

CONCLUSION

Blood IP-10 mRNA expression level may be a potential diagnostic marker to help distinguish active TB from LTBI in PHC.

Caregivers' knowledge and perceptions are associated with children's TB preventive treatment completion

SETTING

Forty-six health centers in south Lima, Peru.

OBJECTIVE

To assess the association between caregivers' knowledge and perceptions around isoniazid preventive therapy (IPT) and whether their children complete IPT.

DESIGN

We conducted a retrospective medical record review of children who initiated IPT during 2017-2018. We administered structured surveys to caregivers of the children about their knowledge about and perceptions of IPT. We used a modified Poisson regression to determine factors associated with IPT completion.

RESULTS

We included 550 children, of whom 31% did not complete IPT. Independent factors associated with not completing IPT were low caregiver knowledge about TB and IPT (adjusted risk ratio [aRR] 1.41, 95% CI 1.06-1.78), low caregiver perception of the importance of IPT (aRR 1.76, 95% CI 1.30-2.39), low caregiver satisfaction with the health services (aRR 1.57, 95% CI 1.14-2.16), experience of adverse events (aRR 2.08, 95% CI 1.51-2.87), and living in a household with moderate or severe family dysfunction (aRR 1.53, 95% CI 1.07-2.19).

CONCLUSION

IPT completion among children was associated with the knowledge and perceptions of their caregivers, as well as the experience of adverse events. To improve IPT completion among children, health care providers should prioritize education and counseling for caregivers, promote positive interpersonal relationships with them, and monitor adverse events.

Prevalence of Mycobacterium tuberculosis infection as measured by the QuantiFERON-TB Gold assay and ESAT-6 free IGRA among adolescents in Mwanza, Tanzania

Background

The prevalence of latent tuberculosis infection (LTBI) is vastly higher than that of tuberculosis (TB) disease and this enormous reservoir of individuals with LTBI impacts the global TB control strategy. Adolescents are at greatest risk of TB infection and are thus an ideal target population for a potential effective TB vaccine to be added to the current BCG programme as it could reduce the number of latent infections and consequently the number of adults with TB disease. However, LTBI rates are often unknown for this population. This study aims to estimate the magnitude of LTBI and to determine if Tanzanian adolescents would be a good population for a prevention of TB infection trial.

Methods

This was a descriptive cross-sectional study that recruited 193 adolescents aged 12 and 16 years from government schools and directly from the community in Mwanza Region, Tanzania. Socio-demographic characteristics were collected for all enrolled participants. Blood was drawn and tested using QuantiFERON-TB Gold In-Tube (QFT-GIT), and Early Secretory Antigenic Target-6–Free Interferon-gamma Release Assay (ESAT-6 free IGRA). Concordance between QFT-GIT and ESAT-6 free IGRA was evaluated using the McNemar’s test.

Results

Overall estimates of LTBI prevalence were 19.2% [95%CI, 14.1; 25.2] and 18.6% [95%CI, 13.6; 24.6] as measured by QFT-GIT IGRA and ESAT-6 free IGRA, respectively. The 16-year-old cohort had a higher LTBI prevalence (23.7% [95%CI, 16.1; 32.9]) as compared to 12-year-old cohort (14.6% [95%CI, 8.6; 22.7]) as measured by QFT-GIT IGRA. When measured by ESAT-6 Free IGRA, LTBI prevalence was 24.7% (95%CI, 16.9; 34.0) for the 16-year-old cohort and 12.5% (95%CI, 7.0; 20.3) among the 12-year-old cohort. According to both tests the prevalence of TB infection and the corresponding annual risk of tuberculosis infection (ARTI) and force of infection were high and increased with age. Of all enrolled participants, 97.4% had concordant results for QFT-GIT IGRA and ESAT-6 free IGRA (p = 0.65).

Conclusions

The prevalence of LTBI and the associated ARTI and force of infection among adolescents is high and increases with age in Mwanza Region. There was a high concordance between the QFT-GIT and the novel ESAT-6 free IGRA assays. These findings suggest Mwanza is a promising area to conduct novel TB vaccine research prevention of infection (POI) studies targeting adolescents.

Xpert MTB/RIF and Xpert MTB/RIF Ultra assays for active tuberculosis and rifampicin resistance in children

BACKGROUND

Every year, at least one million children become ill with tuberculosis and around 200,000 children die. Xpert MTB/RIF and Xpert Ultra are World Health Organization (WHO)-recommended rapid molecular tests that simultaneously detect tuberculosis and rifampicin resistance in adults and children with signs and symptoms of tuberculosis, at lower health system levels. To inform updated WHO guidelines on molecular assays, we performed a systematic review on the diagnostic accuracy of these tests in children presumed to have active tuberculosis.

OBJECTIVES

Primary objectives • To determine the diagnostic accuracy of Xpert MTB/RIF and Xpert Ultra for (a) pulmonary tuberculosis in children presumed to have tuberculosis; (b) tuberculous meningitis in children presumed to have tuberculosis; (c) lymph node tuberculosis in children presumed to have tuberculosis; and (d) rifampicin resistance in children presumed to have tuberculosis - For tuberculosis detection, index tests were used as the initial test, replacing standard practice (i.e. smear microscopy or culture) - For detection of rifampicin resistance, index tests replaced culture-based drug susceptibility testing as the initial test Secondary objectives • To compare the accuracy of Xpert MTB/RIF and Xpert Ultra for each of the four target conditions • To investigate potential sources of heterogeneity in accuracy estimates - For tuberculosis detection, we considered age, disease severity, smear-test status, HIV status, clinical setting, specimen type, high tuberculosis burden, and high tuberculosis/HIV burden - For detection of rifampicin resistance, we considered multi-drug-resistant tuberculosis burden • To compare multiple Xpert MTB/RIF or Xpert Ultra results (repeated testing) with the initial Xpert MTB/RIF or Xpert Ultra result SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, the WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and the International Standard Randomized Controlled Trials Number (ISRCTN) Registry up to 29 April 2019, without language restrictions.

SELECTION CRITERIA

Randomized trials, cross-sectional trials, and cohort studies evaluating Xpert MTB/RIF or Xpert Ultra in HIV-positive and HIV-negative children younger than 15 years. Reference standards comprised culture or a composite reference standard for tuberculosis and drug susceptibility testing or MTBDRplus (molecular assay for detection of Mycobacterium tuberculosis and drug resistance) for rifampicin resistance. We included studies evaluating sputum, gastric aspirate, stool, nasopharyngeal or bronchial lavage specimens (pulmonary tuberculosis), cerebrospinal fluid (tuberculous meningitis), fine needle aspirates, or surgical biopsy tissue (lymph node tuberculosis).

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed study quality using the Quality Assessment of Studies of Diagnostic Accuracy - Revised (QUADAS-2). For each target condition, we used the bivariate model to estimate pooled sensitivity and specificity with 95% confidence intervals (CIs). We stratified all analyses by type of reference standard. We assessed certainty of evidence using the GRADE approach.

MAIN RESULTS

For pulmonary tuberculosis, 299 data sets (68,544 participants) were available for analysis; for tuberculous meningitis, 10 data sets (423 participants) were available; for lymph node tuberculosis, 10 data sets (318 participants) were available; and for rifampicin resistance, 14 data sets (326 participants) were available. Thirty-nine studies (80%) took place in countries with high tuberculosis burden. Risk of bias was low except for the reference standard domain, for which risk of bias was unclear because many studies collected only one specimen for culture. Detection of pulmonary tuberculosis For sputum specimens, Xpert MTB/RIF pooled sensitivity (95% CI) and specificity (95% CI) verified by culture were 64.6% (55.3% to 72.9%) (23 studies, 493 participants; moderate-certainty evidence) and 99.0% (98.1% to 99.5%) (23 studies, 6119 participants; moderate-certainty evidence). For other specimen types (nasopharyngeal aspirate, 4 studies; gastric aspirate, 14 studies; stool, 11 studies), Xpert MTB/RIF pooled sensitivity ranged between 45.7% and 73.0%, and pooled specificity ranged between 98.1% and 99.6%. For sputum specimens, Xpert Ultra pooled sensitivity (95% CI) and specificity (95% CI) verified by culture were 72.8% (64.7% to 79.6%) (3 studies, 136 participants; low-certainty evidence) and 97.5% (95.8% to 98.5%) (3 studies, 551 participants; high-certainty evidence). For nasopharyngeal specimens, Xpert Ultra sensitivity (95% CI) and specificity (95% CI) were 45.7% (28.9% to 63.3%) and 97.5% (93.7% to 99.3%) (1 study, 195 participants). For all specimen types, Xpert MTB/RIF and Xpert Ultra sensitivity were lower against a composite reference standard than against culture. Detection of tuberculous meningitis For cerebrospinal fluid, Xpert MTB/RIF pooled sensitivity and specificity, verified by culture, were 54.0% (95% CI 27.8% to 78.2%) (6 studies, 28 participants; very low-certainty evidence) and 93.8% (95% CI 84.5% to 97.6%) (6 studies, 213 participants; low-certainty evidence). Detection of lymph node tuberculosis For lymph node aspirates or biopsies, Xpert MTB/RIF pooled sensitivity and specificity, verified by culture, were 90.4% (95% CI 55.7% to 98.6%) (6 studies, 68 participants; very low-certainty evidence) and 89.8% (95% CI 71.5% to 96.8%) (6 studies, 142 participants; low-certainty evidence). Detection of rifampicin resistance Xpert MTB/RIF pooled sensitivity and specificity were 90.0% (67.6% to 97.5%) (6 studies, 20 participants; low-certainty evidence) and 98.3% (87.7% to 99.8%) (6 studies, 203 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

We found Xpert MTB/RIF sensitivity to vary by specimen type, with gastric aspirate specimens having the highest sensitivity followed by sputum and stool, and nasopharyngeal specimens the lowest; specificity in all specimens was > 98%. Compared with Xpert MTB/RIF, Xpert Ultra sensitivity in sputum was higher and specificity slightly lower. Xpert MTB/RIF was accurate for detection of rifampicin resistance. Xpert MTB/RIF was sensitive for diagnosing lymph node tuberculosis. For children with presumed tuberculous meningitis, treatment decisions should be based on the entirety of clinical information and treatment should not be withheld based solely on an Xpert MTB/RIF result. The small numbers of studies and participants, particularly for Xpert Ultra, limits our confidence in the precision of these estimates.

Contact evaluation and isoniazid preventive therapy among close and household contacts of tuberculosis patients in Lima, Peru: an analysis of routine data

OBJECTIVE

Contacts of pulmonary tuberculosis (TB) cases are at high risk of TB infection and progression to disease. Close and household contacts and those <5 years old have the highest risk. Isoniazid preventive therapy (IPT) can largely prevent TB disease among infected individuals. International and Peruvian recommendations include TB contact investigation and IPT prescription to eligible contacts. We conducted a study in Lima, Peru, to determine the number of close and household contacts who were evaluated, started on IPT, and who completed it, and the factors associated to compliance with national guidelines.

METHODS

We conducted a longitudinal retrospective study including all TB cases diagnosed between January 2015 and July 2016 in 13 health facilities in south Lima. Treatment cards, TB registers and clinical files were reviewed and data on index cases (sex, age, smear status, TB treatment outcome), contact investigation (sex, age, kinship to the index case, evaluations at month 0, 2 and 6) and health facility (number of TB cases notified per year, proportion of TB cases with treatment success) were extracted. We tabulated frequencies of contact evaluation by contact and index case characteristics. To investigate determinants of IPT initiation and completion, we used generalised linear mixed models.

RESULTS

A total of 2323 contacts were reported by 662 index cases; the median number of contacts per case was four (IQR, 2-5). Evaluation at month 0 was completed by 99.2% (255/257) of contacts <5 and 98.1% (558/569) of contacts aged 5-19 years. Of 191 eligible contacts <5 years old, 70.2% (134) started IPT and 31.4% (42) completed it. Of 395 contacts 5-19 years old, 36.7% (145) started IPT and 32.4% (47) completed it. Factors associated to not starting IPT among contacts <5 years old were being a second-degree relative to the index case (OR 6.6 95CI% 2.6-16.5), not having received a tuberculin skin test (TST) (OR 3.9 95%CI 1.4-10.8), being contact of a smear-negative index case (OR 5.5 95%CI 2.0-15.1) and attending a low-caseload health facility (OR 2.8 95%CI 1.3-6.2). Factors associated to not starting IPT among 5-19 year-olds were age (OR 13.7 95%CI 5.9-32.0 for 16-19 vs. 5-7 years old), being a second-degree relative (OR 3.0 95%CI 1.6-5.6), not having received a TST (OR 5.4, 95%CI 2.5-11.8), being contact of a male index case (OR 2.1 95CI% 1.2-3.5), with smear-negative TB (OR 1.9 95%CI 1.0-3.6), and attending a high-caseload health facility (OR 2.1 95%CI 1.2-3.6). Factors associated to not completing IPT, among contacts who started, were not having received a TST (OR 3.4 95%CI 1.5-7.9 for <5 year-olds, and OR 4.3 95%CI 1.7-10.8 for those 5-19 years old), being contact of an index case with TB treatment outcome other than success (OR 9.3 95%CI 2.6-33.8 for <5 year-olds and OR 15.3 95%CI 1.9-125.8 for those 5-19 years old), and, only for those 5-19 years old, attending a health facility with high caseload (OR 3.2 95%CI 1.4-7.7) and a health facility with low proportion of TB cases with treatment success (OR 4.4 95%CI 1.9-10.2).

CONCLUSIONS

We found partial compliance to TB contact investigation, and identified contact, index case and health facility-related factors associated to IPT start and completion that can guide the TB programme in increasing coverage and quality of this fundamental activity.

Association of Low Sputum Smear Positivity among Tuberculosis Patients with Interferon-Gamma Release Assay Outcomes of Close Contacts in Japan

Risk prediction and response measures may differ in tuberculosis (TB) patients with low sputum smear positivity for acid-fast bacillus (AFB) compared to those who are smear negative. However, previous studies using the tuberculin skin test (TST) did not show that differences in measures are important. This study compared results of interferon-gamma release assays (IGRA) between contacts of pulmonary TB patients with AFB smear positivity and those with smear negativity using QuantiFERON®-TB Gold In-Tube (QFT) assays. Close contacts of TB patients with culture-confirmed infections between April 2010 and December 2012 in Ibaraki, Japan, were enrolled, and 439 Japanese contacts of 129 index TB patients were examined. Adjusted odds ratios of QFT in contacts were 0.68 (95% confidence interval: 0.17-2.8) for AFB scanty patients, 1.12 (0.45-2.8) for AFB 1+, 1.20 (0.48-3.0) for AFB 2+, and 4.96 (1.9-12.9) for AFB 3+, compared to those who were smear negative. Differences in IGRA positivity were not significant between close contacts of TB patients with low positive and negative smears.

Clinical and epidemiological features of tuberculosis in children and adolescents

OBJECTIVE

To analyze the clinical and epidemiological features of tuberculosis in children and adolescents in an infectious diseases reference hospital.

METHOD

A documental and retrospective study was carried out with 88 medical files in an infectious diseases reference hospital in the state of Ceará. Data were analyzed by univariate, bivariate and multivariate approaches.

RESULTS

It was found that, depending on the tuberculosis type, its manifestations may vary. The logistic regression model considered only pulmonary tuberculosis due to a number of observations and included female sex (95% CI: 1.4-16.3), weight loss (95% CI: 1.8-26.3), bacilloscopic screening (95% CI: 1.5-16.6) and sputum collected (95% CI: 1.4-19.4) as possible predictors.

CONCLUSIONS

Children and adolescents present different manifestations of the disease depending on the tuberculosis type that affects them. Knowing the most common features of each condition could enhance early diagnosis and, consequently, result in adequate treatment and care.

Household fuel use and latent tuberculosis infection in a Nepali population

BACKGROUND

The risk of developing latent tuberculosis infection (LTBI) associated with cooking with solid fuels is unknown. This study examined the relationship between household fuel uses and LTBI in adults living in Nepal, a country with a high incidence of tuberculosis.

METHODS

Participants were 1088 adults aged 18-70 years, members of the control group of a population-based case-control study of pulmonary TB (PTB) in people without previous TB, living in Kaski and neighboring districts of Nepal. Participants were interviewed in their homes with a standardized questionnaire. Blood samples were tested for LTBI using an interferon-gamma release assay. Multivariate unconditional logistic regression was used to examine associations between household fuel sources and LTBI.

RESULTS

The overall prevalence of LTBI in the study population was 36%. Using liquefied petroleum gas (LPG) as the baseline cooking fuel type, the adjusted odds ratio (aOR) for using a primary wood cookstove was 1.13 (95%CI: 0.73,1.77) for all participants and, in women only, 1.14 (0.62, 2.09). Corresponding figures for biogas stoves were 0.64 (0.34,1.20) and 0.59 (0.24,1.45), respectively. Household sources of air pollution positively associated with LTBI included traditional oil lamps (diyos) used during power outages, for which the aOR in all participants was 2.53 (1.20, 5.31), although the number of users was small. Use of candles for lighting was also associated with increased risk of LTBI among men (aOR = 1.61, 95% CI:1.01, 2.56).

CONCLUSIONS

No association was found between use of wood for cooking and LTBI. However, there was some evidence that biogas cookstoves were associated with reduced odds of LTBI. Some exposures at the time of actual infection will have been different than the current exposures used in the analysis, biasing results towards the null. Results are sufficient for the use of diyos to be discouraged for lighting purposes. Overall, results suggest that household cooking fuel use is likely to have more effect on moving from the infected state to PTB than on becoming infected with the M. tuberculosis complex. Further research, including longitudinal studies with serial LTBI testing would be useful to more accurately assess the relationships between exposures and infection.

Type 1 interferon-inducible gene expression in QuantiFERON Gold TB-positive uveitis: A tool to stratify a high versus low risk of active tuberculosis?

QuantiFERON-Gold TB (QFT)-positive patients with undetermined cause of uveitis are problematic in terms of whether to diagnose and treat them for tuberculosis (TB). Here, we investigated whether peripheral blood expression of type 1 interferon (IFN)-inducible genes may be of use to stratify QFT-positive patients with uveitis into groups of high versus low risk of having active TB-associated uveitis. We recruited all new uveitis patients in Cipto Mangunkusumo Hospital, Jakarta, Indonesia for one year. We included 12 patients with uveitis and clinically diagnosed active pulmonary TB, 58 QFT-positive patients with uveitis of unknown cause, 10 newly diagnosed sputum-positive active pulmonary TB patients without uveitis and 23 QFT-negative healthy controls. Expression of 35 type 1 IFN-inducible genes was measured in peripheral blood cells from active pulmonary TB patients without uveitis and healthy controls. Differentially expressed genes were identified and used for further clustering analyses of the uveitis groups. A type-1 IFN gene signature score was calculated and the optimal cut-off value for this score to differentiate active pulmonary TB from healthy controls was determined and applied to QFT-positive patients with uveitis of unknown cause. Ten type 1 IFN-inducible genes were differentially expressed between active pulmonary TB and healthy controls. Expression of these 10 genes in QFT-positive patients with uveitis of unknown cause revealed three groups: 1); patients resembling active pulmonary TB, 2); patients resembling healthy controls, and 3); patients displaying an in-between gene expression pattern. A type 1 IFN gene signature score ≥5.61 displayed high sensitivity (100%) and specificity (91%) for identification of active TB. Application of this score to QFT-positive patients with uveitis of unknown cause yielded two groups with expected different likelihood (high vs. low) of having active-TB uveitis, and therefore may be useful in clinical management decisions.

Tuberculosis and other causes of uveitis in Indonesia

PurposeThe purpose of this study is to assess the causes of uveitis in Indonesia and determine the importance of tuberculosis (TB) as a cause of uveitis.Patients and methodsProspective cohort study examining 146 consecutive new human immunodeficiency virus-negative patients with active uveitis between June 2014 and May 2015. We assessed the anatomic locations and specific causes of uveitis, as well as associations with infectious and non-infectious systemic diseases. We determined the prevalence of positive QuantiFERON Tb Gold test (QFT) results in Indonesian patients with uveitis and calculated the number of patients with active systemic TB.ResultsPosterior and panuveitis were the most common anatomic entities (38% each). Infections represented the most frequent cause of uveitis (33%); the most prevalent were toxoplasmosis (19%) and active systemic TB (8%). The majority of patients were QFT positive (61%). A specific diagnosis could not be established in 45% of the patients. At first presentation to the ophthalmologist, the majority of patients (66%) had a visual acuity of less than finger counting at 3 m and already exhibited various complications of uveitis. When classifying the QFT-positive patients with unexplained uveitis into a TB-related group, the percentage of 'TB-associated' uveitis cases increased from 8-48%. Highly elevated QFT levels were observed in patients with uveitis of unknown cause and no signs of active systemic TB.ConclusionsIn Indonesia, infectious uveitis was the most common type of uveitis and the leading causes consisted of toxoplasmosis and TB. The association observed between highly elevated QFT results and uveitis of otherwise unexplained origins indicates that a link exists between the latent TB infection and the development of uveitis.