New Diagnostics for Childhood Tuberculosis

Does multiple gastric aspirate collection increase sensitivity of M. tuberculosis detection in children with pulmonary tuberculosis?

This study aims to investigate the sensitivity of microscopy, culture and polymerase chain reaction on three gastric aspirates (GAs) in the microbiological confirmation of active pulmonary tuberculosis (TB) and to identify possible changes in sensitivity derived from the collection of a different number of aspirates. Children with clinical and radiological diagnoses of active pulmonary TB who underwent three GAs between March 2007 and June 2019 were retrospectively evaluated. Clinical, radiological, and microbiological data were collected. The sensitivity of microbiological tests on GAs was calculated. Moreover, differences in sensitivity according to age and radiological pattern were investigated. Overall, 156 children with active pulmonary TB were enrolled with a median age of 51.5 (IQR: 25.2-113.2) months. Microbiological investigations on the first GA showed a sensitivity of 34% (95%CI 26.7, 42), the cumulative sensitivity of first and second GAs was 40.4% (95%CI 32.7, 48.5) and of the three GAs was 47.4% (95%CI 39.8, 55.2). The collection of three GAs leads to an overall increase in sensitivity of the first GA by 13.4% (95%CI 2.8, 24.1%; p=0.014). Moreover, the increase in sensitivity was significantly higher in children ≤ 4 years of age and in those with uncomplicated TB (p=0.008).Conclusions: Performing a higher number of GAs increases the sensitivity of microbiological confirmation of active pulmonary TB, particularly in children ≤ 4 years and with an uncomplicated radiological pattern. What is known: • The diagnosis of paediatric tuberculosis is a challenge for paediatricians • Despite their low sensitivity gastric aspirates represent the standard sample for microbiological confirmation of active pulmonary tuberculosis in children • Most international guidelines recommend performing three sequential gastric aspirates on three consecutive days What is new: • A significant increase in global sensitivity by 13.4% was found by the collection of three gastric aspirates compared to the first one • Performing a higher number of gastric aspirates increases the sensitivity of microbiological confirmation, particularly in children ≤ 4 years and with an uncomplicated radiological pattern.

Small molecule bio-signature in childhood intra-thoracic tuberculosis identified by metabolomics

The diagnosis of pediatric tuberculosis (TB) remains a major challenge, hence the evaluation of new tools for improved diagnostics is urgently required. We investigated the serum metabolic profile of children with culture-confirmed intra-thoracic TB (ITTB) (n = 23) and compared it with those of non-TB controls (NTCs) (n = 13) using proton NMR spectroscopy-based targeted and untargeted metabolomics approaches. In targeted metabolic profiling, five metabolites (histidine, glycerophosphocholine, creatine/phosphocreatine, acetate, and choline) differentiated TB children from NTCs. Additionally, seven discriminatory metabolites (N-α-acetyl-lysine, polyunsaturated fatty acids, phenylalanine, lysine, lipids, glutamate + glutamine, and dimethylglycine) were identified in untargeted metabolic profiling. The pathway analysis revealed alterations in six metabolic pathways. The altered metabolites were associated with impaired protein synthesis, hindered anti-inflammatory and cytoprotective mechanisms, abnormalities in energy generation processes and membrane metabolism, and deregulated fatty acid and lipid metabolisms in children with ITTB. The diagnostic significance of the classification models obtained from significantly distinguishing metabolites showed sensitivity, specificity, and area under the curve of 78.2%, 84.6%, and 0.86, respectively, in the targeted profiling and 92.3%, 100%, and 0.99, respectively, in the untargeted profiling. Our findings highlight detectable metabolic changes in childhood ITTB; however, further validation is warranted in a large cohort of the pediatric population.

Treatment of Stage I-III Hip Joint Tuberculosis With Open Surgical Debridement and Hip Spica in Children: A Retrospective Study

BACKGROUND

This study aimed to evaluate the outcome of surgical debridement combined with postoperative hip spica immobilization in the treatment of hip joint tuberculosis in children.

METHODS

This retrospective study enrolled 87 children with stage I to III hip joint tuberculosis treated surgically at our hospital from January 2010 to January 2016. All patients considering hip tuberculosis routinely received a 4-week conservative treatment first, including rest, protected weight-bearing, and 4-drugs antitubercular chemotherapy. Surgical debridement was indicated when there was no relief after this conservative protocol. Patients were divided into 2 groups according to the duration of hip spica immobilization after operation: group A (hip spica for 4 wk, 39 patients) and group B (hip spica for 6 wk, 48 patients). All patients were recommended partial weight-bearing for 7 days and then followed the same hip joint exercises program when spica was removed. Postoperative radiographs, hip dislocation or subluxation, and modified Harris hip score (MHHS) were assessed. All patients were followed up at least 5 years.

RESULTS

There were 87 patients enrolled in our study, including 34 females and 53 males, with a mean age of 7.2±2.8 years old (range: 2 to 14 y). No significant difference was observed between these 2 groups in baseline data. In group A, the mean MHHS improved from 52.1±14.7 before surgery to 87.8±8.3 at the final follow-up ( P <0.000). In group B, there was also a significant difference between the preoperative MHHS (52.7±9.4) and the final MHHS (88.6±6.5) ( P <0.000). Although there was no significant difference between these 2 groups in the final MHHS ( P =0.593), there were also no significant differences between these 2 groups in wound healing delay (3 in group A and 6 in group B, P =0.705) and pathologic subluxation (3 in group A and 1 in group B, P =0.467). The only difference between group A (79.2±8.5) and group B (75.5±7.5) was the early functional outcome assessed by using MHHS after 1 month of hip joint exercises ( P =0.032).

CONCLUSIONS

Surgical debridement combined with antitubercular chemotherapy is an effective treatment for stage I to III hip tuberculosis in children when there is no improvement after conservative treatment. Prolonged hip spica immobilization may not reduce the risk of hip subluxation after open surgical debridement but could lead to a delay in early functional recovery. Time of spica immobilization should be individualized and based on the surgeon's evaluation and the patient's condition.

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.

High Inborn Errors of Immunity Risk in Patients with Granuloma

OBJECTIVE

Granuloma etiology includes infections, vasculitis, chemicals, malignancies, lymphoproliferative disorders, and immunological diseases. We hypothesized that patients with granuloma have an underlying primary immunodeficiency disease (PIDD).

PATIENTS AND METHODS

We retrospectively enrolled 82 patients with immunological evaluation among 294 biopsy-proven granuloma patients (0- to 20-year-old). At the same time frame, we followed up with 1910 patients in the same age group.

RESULTS

Out of 82 patients, male/female ratio was 45/37. Median age at symptom onset was 5 years (28 days-17.4 years), age of granuloma at diagnosis was 8.6 years (36 days-19.4 years). Common symptoms at disease onset were fever (23.2%), lymphadenopathy (19.6%), abdominal pain (12.2%), and cough (12.2%). Granuloma was frequent in lymph nodes (26.8%), skin (19.5%), lung (13.4%), and bone (11%). Common infectious agents isolated were Mycobacterium spp. (23.2%) and EBV (4.9%). We document PIDD in 76.8% (63/82) of patients. 49.4% (40/81) of immunologically evaluated granuloma patients had hypogammaglobulinemia. Granuloma rate in pediatric PIDD was 3.3%(63/1910). Patients with multiple granulomas (n = 16) had a PIDD diagnosis. Lung involvement was three times more in PIDD. Brain involvement was only seen in PIDD. Fibroadipose tissue and liver involvement were more frequent in patients without documented PIDD and patients whose evaluation was not completed. The mortality rate in PIDD with granuloma was 15.9%, whereas there was no mortality in patients without PIDD.

CONCLUSION

As documented here, even in a university hospital, the immunologic evaluation ratio is about one-third. We showed high PIDD frequency in children with granuloma, and higher mortality in PIDD with granuloma. Thus, an immunologic evaluation performed meticulously by immunologists is a must for accurate diagnosis and decision of individualized therapeutic options.

Reproducibility of a protocol for standardized reading of chest X-rays of children household contact of patients with tuberculosis

BACKGROUND

The interpretation of the chest radiograph may vary because it depends on the reader and due to the non-specificity of findings in tuberculosis (TB). We aim to assess the reproducibility of a standardized chest radiograph reading protocol in contacts of patients with pulmonary TB under the 5 years of age.

METHODS

Descriptive, cross-sectional study with children under the age of five, household contacts of patients with confirmed pulmonary TB from Medellín, Bello and Itagüí (Colombia) between Jan-01-2015 and May-31-2016. Standardized reading protocol: two radiologists, blinded independent reading, use of template (Dr. Andronikou design) in case of disagreement a third reading was performed. Kappa coefficient for intra and inter observer agreement, and prevalence ratio were estimated of sociodemographic characteristics, TB exposure and interpretation of chest X-ray.

RESULTS

From 278 children, standardized reading found 255 (91.7%) normal X-rays, 10 (3.6%) consistent with TB, and 13 (4.7%) other alterations. Global agreement was 91.3% (Kappa = 0.51). Inter-observer agreement between readers 1-2 was 90.0% (Kappa = 0.59) and 1-3 93.2% (Kappa = 0.59). Intra-observer agreement for reader 1 was 95.5% (Kappa = 0.86), 2 84.0% (Kappa = 0.51), and 3 94.7% (Kappa = 0.68). Greater inter-observer disagreement was between readers 1-2 for soft tissue density suggestive of adenopathy (4.6%), airspace opacification (1.17%) and pleural effusion (0.58%); between readers 1-3 for soft tissue density suggestive of adenopathy (4.2%), opacification of airspace (2.5%) and cavities (0.8%).

CONCLUSIONS

Chest radiographs are an affordable tool that contributes to the diagnosis of TB, so having a standardized reading protocol showed good agreement and improves the reproducibility of radiograph interpretation.

Facilitators and Barriers to Implementation of a Childhood Tuberculosis Control Program in Bangladesh: A Mixed-Methods Study from BRAC Urban DOTS Centres in Dhaka

The case detection rate of childhood tuberculosis in Bangladesh is 4%, far below the World Health Organization predicted rate of 10–15% for a country with a high burden of tuberculosis. A concurrent triangulation mixed-methods study was carried out in eight urban DOTS (Directly Observed Treatment, Short-course) centres to investigate the factors contributing to the diagnosis and treatment of childhood tuberculosis. Front-line health care workers (Shasthya Shebika) (n = 111) were surveyed to understand knowledge, attitude, and practice (KAP) of the diagnosis and treatment of childhood tuberculosis. In-depth interviews were conducted with field workers (n = 32) and mothers of TB cases (n = 4). Stakeholders involved in implementing the tuberculosis program (n = 9) participated in the key informant interviews. Knowledge of Shasthya Shebika was associated with the components addressed during refresher training (p = 0.02). Government stewardship, presence of specific guidelines, knowledge and capacity building of front-line health workers were identified as the key facilitators. Frequent turnover of key managerial positions in the government, stigma, delays in seeking care, lack of diagnostic facilities, and poor engagement of private practitioners were identified as major constraints. It was identified that the government should focus on improving diagnostic capacities, conduct research on childhood tuberculosis, and produce awareness materials.

Evaluation of Sputum-Culture Results for Tuberculosis Patients in the United States-Affiliated Pacific Islands

Sputum-culture confirmation guides tuberculosis (TB) diagnosis and patient management but has previously been reported to be low in the US-Affiliated Pacific Islands (USAPI). We evaluated factors associated with positive sputum-culture results by analyzing TB case surveillance and laboratory data, including sputa quality and quantity for diagnostic specimens from the USAPI. A lower proportion of sputum specimens were reported as culture positive from the USAPI (42%), compared with Hawaii (58%) and the United States (55%). Few (3%) sputa collected from TB patients in the USAPI had both optimal quality and quantity; 40% had optimal quality (mucoid), and 7% had optimal quantity (>5 mL). Suboptimal sputum specimen quality and quantity contributed to fewer sputum-culture positive results in the USAPI. Improving sputum collection and handling might lead to more culture positive results and ultimately improve patient care and TB control in USAPI.

Retrospective cohort analysis of survival of children living with HIV/AIDS in Mumbai, India

OBJECTIVES

To understand the survival in a cohort of children living with HIV/AIDS (CLHAs) and to study the factors associated with survival in CLHAs in government antiretroviral therapy (ART) centres in Mumbai, India.

DESIGN

This is a retrospective cohort analysis.

SETTING

Data from electronic ART records of children from 15 ART centres in Mumbai, Maharashtra, India.

PARTICIPANTS

2224 CLHAs registered in one of these ART centres from 2004 until October 2019. CLHAs up to the age of 18 at the time of registration were considered for these analyses.

PRIMARY AND SECONDARY OUTCOMES

We accessed the following data: date of test, date of initiation of ART, date of last follow-up, age at the time of registration, gender, potential route of infection, baseline CD4 counts, ART regimen, adherence and presence of co-infection (TB). We estimated the survival probabilities, plotted the Kaplan-Meier survival graphs and estimated HRs for mortality.

RESULTS

The mortality rate in our population was 22.75 (95% CI 20.02 to 25.85) per 1000 person-years. The 1-year survival was 0.92 (95% CI 0.91 to 0.93), 0.89 (95% CI 0.88 to 0.91) at 5 years and 0.85 (95% CI 0.83 to 0.87) at 10 years after initiation of ART. Children with adherence less than 80% had lowest survival in the first year (0.54, 95% CI 0.46 to 0.61). It reduced drastically at 5 and 10 years. After adjusting for demographic and clinical parameters, mortality was associated with poor adherence (<80%) (HR 11.70, 95% CI 8.82 to 15.53; p<0.001). However, CD4 counts of greater than 200 and age more than 1 year were protective.

CONCLUSIONS

Poor adherence to ART and low CD4 counts were significantly associated with higher mortality. Adherence counselling should be an important component of CLHA monitoring in all ART centres. It is also important to identify children early in the infection and start ART medications appropriately.

Evaluation of TB-LAMP assay for detection of Mycobacterium tuberculosis in children

BACKGROUND

Paediatric tuberculosis remains a major public health problem in developing countries. The diagnosis of tuberculosis in children is challenging because of the paucibacillary nature of the disease, due to which more sensitive nucleic acid amplification tests are needed. In this study, we determined the accuracy of WHO endorsed TB-LAMP assay for detection of Mycobacterium tuberculosis in children.

METHODS

This was a prospective study conducted between March to July, 2018. A total of 177 samples from consecutive suspected TB children were received for microbiological diagnosis of TB. All tests for Mycobacterium tuberculosis detection were performed in parallel (smear microscopy, mycobacterial culture, Xpert MTB/RIF and TB-LAMP). The diagnostic accuracy of index test i.e. TB LAMP were determined using mycobacterial culture as a reference standard.

RESULTS

Of the 177 samples, 2 (1.1%) were excluded from the study. Among 175 samples, TB-LAMP and Xpert MTB/RIF were positive in 27 (15.4%) and 25 (14.3%) samples, respectively. The sensitivity of both Xpert MTB/RIF and TB-LAMP was same, i.e. 84% (95%CI: 63.9-95.5%), when culture was considered as the reference standard. The specificity, positive predictive value and negative predictive value of TB-LAMP assay was 96% (95%CI: 91.5-98.5%), 77.8% (95%CI: 61.1-88.6%) and 97.3% (95%CI: 93.6-98.9%), respectively.

CONCLUSION

For the detection of M. tuberculosis in paediatric samples, TB-LAMP showed a sensitivity and specificity comparable to Xpert MTB/RIF.

Development and clinical evaluation of a new multiplex PCR assay for a simultaneous diagnosis of tuberculous and nontuberculous mycobacteria

BACKGROUND

The prevalence of non-tuberculous mycobacteria (NTM) has been increasing worldwide in both developed and developing countries. NTM infection is clinically indistinguishable from tuberculosis and therefore poses significant challenges in patient management, especially in patients chronically treated for pulmonary TB. In this study, we evaluated a new highly sensitive Multiplex MTB/NTM assay that can differentiate M. tuberculosis complex (MTBC) from all NTM, including the treatable and most common NTM, M. avium complex (MAC).

METHODS

We developed and optimized a new open- Multiplex MTB/NTM assay with two gene-targets for MTBC (IS6110/senX3-regX3) and two targets for MAC (IS1311/DT1) with samples spiked with stored strains and testing 20 replicates. Patients with presumptive TB and NTM were enrolled at the Respiratory Disease Department of The University Teaching Hospital of Point G, in Mali.

FINDINGS

In the development stage, the new assay showed a high analytic performance with 100% detections of MTBC and MAC at only 5 colony forming units (CFUs). Overall, without the treatment failure cases, the Multiplex assay and the Xpert showed a sensitivity, specificity, PPV and NPV of 83·3% [66·4-92·6], 96·6% [88·6-99·0], 92·5% [82·3-96·5] and 92·2% [82·7-96·5] and the Xpert had values of 96·7% [83·3-99·4], 80·0% [68·2-88·1], 70·7 [55·5-82·3] and 97·9% [89·3-99·6], respectively. The Multiplex assay successfully detected all (5/5) the MAC cases.

INTERPRETATION

Our new Multiplex assay demonstrates better specificity than Xpert for all group studied, in addition to detecting potential NTM cases. The assay could therefore complement the widely used Xpert assay and enhance discrimination of TB and NTM infections.

FUNDING

This work was supported by the National Institutes of Health (R03AI137674, U54EB027049, D43TW010350 and UM1AI069471) and Northwestern University's Institute for Global Health Catalyzer Fund.

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.

Advanced imaging tools for childhood tuberculosis: potential applications and research needs

Tuberculosis is the leading cause of death globally that is due to a single pathogen, and up to a fifth of patients with tuberculosis in high-incidence countries are children younger than 16 years. Unfortunately, the diagnosis of childhood tuberculosis is challenging because the disease is often paucibacillary and it is difficult to obtain suitable specimens, causing poor sensitivity of currently available pathogen-based tests. Chest radiography is important for diagnostic evaluations because it detects abnormalities consistent with childhood tuberculosis, but several limitations exist in the interpretation of such results. Therefore, other imaging methods need to be systematically evaluated in children with tuberculosis, although current data suggest that when available, cross-sectional imaging, such as CT, should be considered in the diagnostic evaluation for tuberculosis in a symptomatic child. Additionally, much of the understanding of childhood tuberculosis stems from clinical specimens that might not accurately represent the lesional biology at infection sites. By providing non-invasive measures of lesional biology, advanced imaging tools could enhance the understanding of basic biology and improve on the poor sensitivity of current pathogen detection systems. Finally, there are key knowledge gaps regarding the use of imaging tools for childhood tuberculosis that we outlined in this Personal View, in conjunction with a proposed roadmap for future research.

Caracterización de los pacientes menores de 15 años con tuberculosis en el Hospital Universitario San Vicente Fundación, 2011-2018

La Tuberculosis (TB) es la enfermedad infecciosa que más daño ha causado a la especie humana a lo largo de toda la historia, tanto por el número de enfermos como de muertos. Se ha calculado que en los últimos 200 años ha sido la responsable de la muerte de más de 1.000 millones de personas (1). La TB sigue siendo una de las enfermedades infecciosas más importante en esta época, y es el fiel reflejo de las enormes diferencias económicas y sociales que siguen existiendo en la población mundial1,2. Objetivo: describir las características demográficas y clínicas de los pacientes menores de 15 años con TB en el período 2011 – 2018 en un Hospital de cuarto nivel de la ciudad de Medellín – Colombia. Metodología: estudio observacional descriptivo de corte transversal. Incluyó pacientes menores de 15 años que asistieron al Hospital Universitario San Vicente Fundación (HUSVF) a quienes se les diagnosticó TB pulmonar y/o extrapulmonar, en el período comprendido entre enero de 2011 a diciembre de 2018. Resultados: 184 historias de pacientes con TB cumplieron los criterios de inclusión. Setenta y un pacientes (38.6 %) correspondían a TB pulmonar, 59 (32 %) a otras TB intratorácicas y 54 (29.3 %) a TB extrapulmonar. Las formas de TB más frecuentes fueron: ganglionar, del sistema nervioso central (SNC) y diseminada. De los niños menores de 5 años, el 50 % presentaron algún grado de desnutrición. La confirmación microbiológica por cultivo o baciloscopia (BK) estuvo presente en 91 pacientes (49.4 %) y por Reacción en Cadena de la Polimerasa (PCR) en 72 (39.1 %). Conclusiones: la TB infantil requiere un alto índice de sospecha. La suma de criterios es muy importante para su diagnóstico dada la fisiopatología de la enfermedad, sin embargo la búsqueda exhaustiva de la micobacteria es una estrategia útil para un tratamiento efectivo.

Performance of metabonomic serum analysis for diagnostics in paediatric tuberculosis

We applied a metabonomic strategy to identify host biomarkers in serum to diagnose paediatric tuberculosis (TB) disease. 112 symptomatic children with presumptive TB were recruited in The Gambia and classified as bacteriologically-confirmed TB, clinically diagnosed TB, or other diseases. Sera were analysed using ¹H nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Multivariate data analysis was used to distinguish patients with TB from other diseases. Diagnostic accuracy was evaluated using Receiver Operating Characteristic (ROC) curves. Model performance was tested in a validation cohort of 36 children from the UK. Data acquired using ¹H NMR demonstrated a sensitivity, specificity and Area Under the Curve (AUC) of 69% (95% confidence interval [CI], 56-73%), 83% (95% CI, 73-93%), and 0.78 respectively, and correctly classified 20% of the validation cohort from the UK. The most discriminatory MS data showed a sensitivity of 67% (95% CI, 60-71%), specificity of 86% (95% CI, 75-93%) and an AUC of 0.78, correctly classifying 83% of the validation cohort. Amongst children with presumptive TB, metabolic profiling of sera distinguished bacteriologically-confirmed and clinical TB from other diseases. This novel approach yielded a diagnostic performance for paediatric TB comparable to that of Xpert MTB/RIF and interferon gamma release assays.

Adolescent tuberculosis

Adolescence is characterised by a substantial increase in the incidence of tuberculosis, a known fact since the early 20th century. Most of the world's adolescents live in low-income and middle-income countries where tuberculosis remains common, and where they comprise a quarter of the population. Despite this, adolescents have not yet been addressed as a distinct population in tuberculosis policy or within tuberculosis treatment services, and emerging evidence suggests that current models of care do not meet their needs. This Review discusses up-to-date information about tuberculosis in adolescence, with a focus on the management of infection and disease, including HIV co-infection and rifampicin-resistant tuberculosis. We outline the progress in vaccine development and highlight important directions for future research.

Tuberculosis: An Epidemic Perpetuated by Health Inequalities

Tuberculosis (TB) is the leading single-agent infectious disease killer worldwide. The World Health Organization (WHO)'s End TB Strategy aims to achieve tuberculosis (TB) elimination by 2030, and in September 2018, the United Nations General Assembly held a High-Level Meeting on TB to address the urgency of the TB epidemic and the health inequalities that continue to propel it. The meeting endorsed an ambitious, comprehensive approach to the TB epidemic that incorporates universal health coverage and tackles the social determinants of this disease. In this article, we provide an overview of the key strategies promoted in this meeting and introduce work by five Rhode Island-based physicians that align with these goals.

Epidemiological characteristics of pulmonary tuberculosis among children in Shandong, China, 2005-2017

BACKGROUND

Diagnosis of tuberculosis (TB) in children is challenging. Epidemiological data of childhood pulmonary tuberculosis (PTB) are urgently needed.

METHODS

We described trends in epidemiology, clinical characteristics, and treatment outcomes in seven cities of Shandong province, China, during 2005-2017. Data were collected from the China Information System for Disease Control and Prevention.

RESULTS

Among 6283 (2.4% of all PTB) PTB cases aged < 18 years, 56.5% were male patients, 39.3% were smear-positive and 98.6% were new cases. The overall incidence of childhood PTB declined (7.62 to 3.74 per 100,000) during 2005-2017, with a non-significant change of annual percentage after 2010. While the incidence of smear-positive PTB (6.09 to 0.38 per 100,000 population) decreased significantly, but the incidence of smear-negative PTB (1.52 to 3.36 per 100,000 population) increased significantly during 2005-2017. The overall treatment success occurred among 94.2% childhood PTB. Ten children (0.2%) died.

CONCLUSION

The overall incidence of childhood PTB declined significantly with the disease burden shifting from smear-positive PTB to smear-negative PTB. The discrepancies between notifications and estimations in both TB morbidity and mortality of children need to be addressed urgently.

Pediatric Multidrug-resistant Tuberculosis in Kyiv City, Ukraine

Few reports have described pediatric Multidrug-resistant Tuberculosis (MDR-TB) in the former Soviet republics, despite the fact that these countries have the highest proportion of TB cases that are MDR. We aimed to examine pediatric MDR-TB in Ukraine. This retrospective cohort study included all children <18 years of age who started undergoing MDR-TB treatment between January 1, 2011 and July 31, 2016 at Kyiv City Pediatric TB Hospital. From each child's clinical chart, we abstracted demographic and clinical data. Using Fisher's exact test, we compared characteristics between children with microbiologically confirmed vs. probable (i.e., clinically diagnosed) MDR-TB. The study population included 20 children with a median age of 5 years. At diagnosis, 12 (60%) had intrathoracic lymphadenopathy as their only radiographic abnormality, and two (10%) were asymptomatic. Children with confirmed MDR-TB were more likely to be adolescents or have radiologic abnormalities in addition to intrathoracic lymphadenopathy. Median treatment duration was 20 months. Eighteen (90%) children were treated successfully. The remaining two were transferred to another facility, and their final outcomes were unknown. The excellent outcomes in this cohort are consistent with high treatment success rates for pediatric MDR-TB reported in other parts of the world.

Recent Innovations in Diagnosis and Treatment of Pediatric Tuberculosis

PURPOSE OF REVIEW

Tuberculosis is leading cause of global morbidity and mortality and a significant proportion of the burden of disease occurs in children. In the past 5 years, a number of innovations have improved the diagnosis and treatment for children with both latent tuberculosis infection and active disease.

RECENT FINDINGS

This review discusses three key areas of innovation. First, we assess utilization and performance of interferon-gamma release assays (IGRAs) in different clinical and epidemiologic scenarios. Recent literature has demonstrated good performance of IGRAs for diagnosis of latent tuberculosis infection, particularly in low-incidence settings such as TB control programs in North America. For high-incidence populations, or when testing is done for possible active TB disease, IGRA performance has some important limitations, but IGRA sensitivity when measured against culture proven disease may be better than earlier studies suggested. The second area of innovation is in increased uptake of nucleic acid amplification (NAA) tests and broader application in non-sputum samples for both pediatric pulmonary and extrapulmonary tuberculosis. Finally, recent studies have provided solid evidence in support of shorter treatment courses for pediatric latent tuberculosis infection, such as 12 weeks of weekly isoniazid and rifapentine or 4 months daily rifampin, that improve compliance and may reduce resources required for TB control. Many recent innovations in pediatric tuberculosis relate to an improved understanding of how to optimally use existing tests and treatments. Until diagnostic tests and interventions such as vaccination are developed that can dramatically alter the paradigm of pediatric TB management and control, it is important for stakeholders to have a nuanced understanding of tools currently available.

Constructing care cascades for active tuberculosis: A strategy for program monitoring and identifying gaps in quality of care

The cascade of care is a model for evaluating patient retention across sequential stages of care required to achieve a successful treatment outcome. This approach was first used to evaluate HIV care and has since been applied to other diseases. The tuberculosis (TB) community has only recently started using care cascade analyses to quantify gaps in quality of care. In this article, we describe methods for estimating gaps (patient losses) and steps (patients retained) in the care cascade for active TB disease. We highlight approaches for overcoming challenges in constructing the TB care cascade, which include difficulties in estimating the population-level burden of disease and the diagnostic gap due to the limited sensitivity of TB diagnostic tests. We also describe potential uses of this model for evaluating the impact of interventions to improve case finding, diagnosis, linkage to care, retention in care, and post-treatment monitoring of TB patients.

Multidrug-resistant tuberculosis infection and disease in children: a review of new and repurposed drugs

The World Health Organization estimates that 10 million new cases of tuberculosis (TB) occurred worldwide in 2017, of which 600,000 were rifampicin or multidrug-resistant (RR/MDR) TB. Modelling estimates suggest that 32,000 new cases of MDR-TB occur in children annually, but only a fraction of these are correctly diagnosed and treated. Accurately diagnosing TB in children, who usually have paucibacillary disease, and implementing effective TB prevention and treatment programmes in resource-limited settings remain major challenges. In light of the underappreciated RR/MDR-TB burden in children, and the lack of paediatric data on newer drugs for TB prevention and treatment, we present an overview of new and repurposed TB drugs, describing the available evidence for safety and efficacy in children to assist clinical care and decision-making.

Simultaneous diagnosis of tuberculous and non-tuberculous mycobacterial diseases: Time for a better patient management

Tuberculosis (TB) is the deadliest infectious disease in the world which disproportionately affects low-and-middle-income countries (LMICs) where diagnostic resources and treatment options are limited. The incidence of pulmonary non-tuberculous mycobacteria (NTM) disease is also rapidly increasing in these regions traditionally dominated by TB infections. This poses significant diagnostic and treatment challenges, since these two diseases are often indistinguishable clinically or by sputum smear microscopy (SSM), the most commonly used TB diagnostic tool in LMICs. Consequently, NTM-infected patients usually receive unnecessary TB treatment for months. TB patients with NTM co-infections may also be treated incorrectly due to inaccurate SSM and Xpert™ MTB/RIF (M. tuberculosis./rifampin) results. These issues complicate the management of patients and contribute to the worsening of the current TB and NTM epidemiological features including development of drug resistant strains. It is therefore critical to develop improved diagnostic tools to accurately distinguish these two different pathogens that have many similar clinical and epidemiological features but have different treatment regimens. In this review, we will discuss limitations with current diagnostic tools and the need to develop novel techniques that can accurately and simultaneously diagnose TB and NTM disease._.

Feasibility of the string test for tuberculosis diagnosis in children between 4 and 14 years old

BACKGROUND

The enteric string test can be used to obtain a specimen for microbiological confirmation of tuberculosis in children, but it is not widely used for this. The aim of this analysis to evaluate this approach in children with tuberculosis symptoms.

METHODS

We conducted a cross-sectional study to assess children's ability to complete the test (feasibility), and self-reported pain (tolerability). We examined caregivers' and children's willingness to repeat the procedure (acceptability) and described the diagnostic yield of cultures for diagnostic tools. We stratified estimates by age and compared metrics to those derived for gastric aspirate (GA).

RESULTS

Among 148 children who attempted the string test, 34% successfully swallowed the capsule. Feasibility was higher among children aged 11-14 than in children 4-10 years (83% vs 22% respectively, p < 0.0001). The string test was better tolerated than GA in both age groups; however, guardians and older children reported higher rates of willingness to repeat GA than the string test (86% vs. 58% in children; 100% vs. 83% in guardians). In 9 children with a positive sputum culture, 6 had a positive string culture. The one children with a positive gastric aspirate culture also had a positive string culture.

CONCLUSION

Although the string test was generally tolerable and accepted by children and caregivers; feasibility in young children was low. Reducing the capsule size may improve test success rates in younger children.

The role of the Xpert MTB/RIF assay among adolescents suspected of pulmonary tuberculosis in Rio de Janeiro, Brazil

INTRODUCTION

The teste rápido molecular para tuberculose (TRM-TB) was introduced in 2014 in Brazil for tuberculosis screening. However, its role in adolescents in Brazil has not been studied.

METHODS

A descriptive study of adolescents with suspected tuberculosis using National Laboratory software.

RESULTS

Of 852 (15.4%) suspected cases, 131 were positive by TRM-TB and 2% were resistant to rifampicin. Among TRM-TB-positive cases, 105 (91.4%) were culture-positive. Sixty-four of 96 samples were sensitive to rifampicin by TRM-TB; 11 were resistant to other drugs by drug sensitivity test (DST).

CONCLUSIONS

Among suspected cases, 16% were diagnosed by TRM-TB, of which 17% were drug-resistant by DST.

A systematic approach to diagnosing intra-thoracic tuberculosis in children

Children suffer a huge and often underappreciated burden of disease in tuberculosis (TB) endemic countries. Major hurdles include limited awareness among health care workers, poor integration of TB into maternal and child health approaches, diagnostic difficulties and a lack of child-friendly treatment options. Accurate disease diagnosis is particularly difficult in young and vulnerable children who tend to develop paucibacillary disease and are unable to produce an expectorated sputum sample. In addition, access to chest radiography is problematic in resource-limited settings. Differentiating between TB exposure and M. tuberculosis infection, and especially between M. tuberculosis infection and TB disease is crucial to guide clinical management. TB represents a dynamic continuum from well-contained "latent" infection to incipient and ultimately severe disease. The clinical spectrum of disease in children is broad and can be confused with a myriad of common infections. We provide a pragmatic 4-step approach to diagnose intra-thoracic TB in children and demonstrate how classifying clinical, radiological and laboratory findings into recognised clinical syndromes may provide a more refined diagnostic approach, even in resource-limited settings.

Childhood multidrug-resistant tuberculosis in the European Union and European Economic Area: an analysis of tuberculosis surveillance data from 2007 to 2015

Confirming tuberculosis (TB) in children and obtaining information on drug susceptibility is essential to ensure adequate treatment. We assessed whether there are gaps in diagnosis and treatment of multidrug-resistant (MDR) TB in children in the European Union and European Economic Area (EU/EEA), quantified the burden of MDR TB in children and characterised cases. Methods: We analysed surveillance data from 2007 to 2015 for paediatric cases younger than 15 years. Results: In that period, 26 EU/EEA countries reported 18,826 paediatric TB cases of whom 4,129 (21.9%) were laboratory-confirmed. Drug susceptibility testing results were available for 3,378 (17.9%), representing 81.8% of the confirmed cases. The majority (n = 2,967; 87.8%) had drug-sensitive TB, 249 (7.4%) mono-resistant TB, 64 (1.9%) poly-resistant TB, 90 (2.7%) MDR TB and eight (0.2%) had extensively drug-resistant (XDR) TB. MDR TB was more frequently reported among paediatric cases with foreign background (adjusted odds ratio (aOR) = 1.73; 95% confidence interval (95% CI): 1.12–2.67) or previous TB treatment (aOR: 6.42; 95% CI: 3.24–12.75). Successful treatment outcome was reported for 58 of 74 paediatric MDR TB cases with outcome reported from 2007 to 2013; only the group of 5–9 years-olds was significantly associated with unsuccessful treatment outcome (crude odds ratio (cOR) = 11.45; 95% CI: 1.24–106.04). Conclusions: The burden of MDR TB in children in the EU/EEA appears low, but may be underestimated owing to challenges in laboratory confirmation. Diagnostic improvements are needed for early detection and adequate treatment of MDR TB. Children previously treated for TB or of foreign origin may warrant higher attention.

Examining the quality of childhood tuberculosis diagnosis in Cambodia: a cross-sectional study

BACKGROUND

Cambodia is one of the 22 countries with the highest TB burden. While childhood TB is estimated to make up 10-20% of total TB cases in high-burden settings, this proportion ranges from 1.3 to 39.4% throughout Cambodia's provinces, suggesting potential under- and over-diagnosis of childhood TB, subnationally. The proportion of case notifications classified as extrapulmonary TB out of total TB case notifications in children is 87%, greatly exceeding the expected global range of 20-30%. There is a gap in the literature on how childhood TB is diagnosed in resource-poor settings, and the quality of diagnoses. The study's aim is to quantitatively assess the quality of clinician performance and availability of diagnostic tools, for diagnosing childhood TB in high-burden Operational Districts in Cambodia.

METHODS

Between August and September of 2015, a cross-sectional study was conducted at referral hospitals and villages in 24 high-burden Operational Districts. 40 clinicians, and 104 parents whose child was recently diagnosed with TB were interviewed. Questionnaires assessed availability of diagnostic tools, and clinician knowledge and practice during a clinical examination. Descriptive statistics were calculated to provide cross-sectional data.

RESULTS

Availability of advanced diagnostic tools was low. Only 27.5% of clinicians had Xpert machines available at their facility, and 5% had equipment to perform gastric aspiration. 77.5% of clinicians reported that they had a chest X-ray at their facility, but only 34.6% of parents reported that the clinician conducted a chest X-ray. 72.5% of clinicians could name 5 out of 7 main TB screening criteria; however, parent data suggests that clinicians may not be applying knowledge to practice. The mean number of examinations/tests the clinician conducted during the clinical assessment of the child was 1.64. Of the parents whose child had an enlarged lymph node, 60.22% described lymph node characteristics that were not suggestive of TB.

CONCLUSION

Limited availability of diagnostic tools and suboptimal clinician performance highlight where resources should be allocated to improve quality of diagnoses. Further research needs to be done in low burden Operational Districts to determine the capacity of clinicians and health facilities for diagnosing childhood TB, where cases are likely being missed.

Tuberculosis: Is the landscape changing?

Robert Heinrich Herman Koch, a German physician and microbiologist, received Nobel Prize in 1905 for identifying the specific causative agent of tuberculosis (TB). During his time it was believed that TB was an inherited disease. However he was convinced that the disease was caused by a bacterium and was infectious, tested his postulates using guinea pigs, and found the causative agent to be slow growing mycobacterium tuberculosis. TB is the second most common cause of death from infectious diseases after HIV/AIDS. Drug-resistant TB poses serious challenge to effective management of TB worldwide. Multidrug-resistant TB accounted for about half a million new cases and over 200,000 deaths in 2013. Whole-genome sequencing (first done in 1998) technologies have provided new insight into the mechanism of drug resistance. For the first time in 50 y, new anti TB drugs have been developed. The World Health Organization (WHO) has recently revised their treatment guidelines based on 32 studies. In United States, latent TB affects between 10 and 15 million people, 10% of whom may develop active TB disease. QuantiFERON TB Gold and T-SPOT.TB test are used for diagnosis. Further research will look into the importance of newly discovered gene mutations in causing drug resistance.

Mortality in children diagnosed with tuberculosis: a systematic review and meta-analysis

BACKGROUND

Case fatality ratios in children with tuberculosis are poorly understood-particularly those among children with HIV and children not receiving tuberculosis treatment. We did a systematic review of published work to identify studies of population-representative samples of paediatric (ie, <15 years) tuberculosis cases.

METHODS

We searched PubMed and Embase for reports published in English, French, Portuguese, or Spanish before Aug 12, 2016, that included terms related to tuberculosis, children, mortality, and population representativeness. We also reviewed our own files and reference lists of articles identified by this search. We screened titles and abstracts for inclusion, excluding studies in which outcomes were unknown for 10% or more of the children and publications detailing non-representative samples. We used random-effects meta-analysis to produce pooled estimates of case fatality ratios from the included studies, which we divided into three eras: the pre-treatment era (ie, studies before 1946), the middle era (1946-80), and the recent era (after 1980). We stratified our analyses by whether or not children received tuberculosis treatment, age (0-4 years, 5-14 years), and HIV status.

FINDINGS

We identified 31 papers comprising 35 datasets representing 82 436 children with tuberculosis disease, of whom 9274 died. Among children with tuberculosis included in studies in the pre-treatment era, the pooled case fatality ratio was 21·9% (95% CI 18·1-26·4) overall. The pooled case fatality ratio was significantly higher in children aged 0-4 years (43·6%, 95% CI 36·8-50·6) than in those aged 5-14 years (14·9%, 11·5-19·1). In studies in the recent era, when most children had tuberculosis treatment, the pooled case fatality ratio was 0·9% (95% CI 0·5-1·6). US surveillance data suggest that the case fatality ratio is substantially higher in children with HIV receiving treatment for tuberculosis (especially without antiretroviral therapy) than in those without HIV.

INTERPRETATION

Without adequate treatment, children with tuberculosis, especially those younger than 5 years, are at high risk of death. Children with HIV have an increased mortality risk, even when receiving tuberculosis treatment.

FUNDING

US National Institutes of Health, Janssen Global Public Health.

Tuberculosis exposure, infection and disease in children: a systematic diagnostic approach

The accurate diagnosis of tuberculosis (TB) in children remains challenging. A myriad of common childhood diseases can present with similar symptoms and signs, and differentiating between exposure and infection, as well as infection and disease can be problematic. The paucibacillary nature of childhood TB complicates bacteriological confirmation and specimen collection is difficult. In most instances intrathoracic TB remains a clinical diagnosis. TB infection and disease represent a dynamic continuum from TB exposure with/without infection, to subclinical/incipient disease, to non-severe and severe disease. The clinical spectrum of intrathoracic TB in children is broad, and the classification of clinical, radiological, endoscopic, and laboratory findings into recognized clinical syndromes allows a more refined diagnostic approach in order to minimize both under- and over-diagnosis. Bacteriological confirmation can be improved significantly by collecting multiple, high-quality specimens from the most appropriate source. Mycobacterial testing should include traditional smear microscopy and culture, as well as nucleic acid amplification testing. A systematic approach to the child with recent exposure to TB, or with clinical and radiological findings compatible with this diagnosis, should allow pragmatic classification as TB exposure, infection, or disease to facilitate timely and appropriate management. It is important to also assess risk factors for TB disease progression and to undertake follow-up evaluations to monitor treatment response and ongoing evidence supporting a TB, or alternative, diagnosis.

Global Burden of Childhood Tuberculosis

In 2015, the World Health Organization (WHO) declared tuberculosis (TB) to be responsible for more deaths than any other single infectious disease. The burden of TB among children has frequently been dismissed as relatively low with resulting deaths contributing very little to global under-five all-cause mortality, although without rigorous estimates of these statistics, the burden of childhood TB was, in reality, unknown. Recent work in the area has resulted in a WHO estimate of 1 million new cases of childhood TB in 2014 resulting in 136,000 deaths. Around 3% of these cases likely have multidrug-resistant TB and at least 40,000 are in HIV-infected children. TB is now thought to be a major or contributory cause of many deaths in children under five years old, despite not being recorded as such, and is likely in the top ten causes of global mortality in this age group. In particular, recent work has shown that TB is an under-lying cause of a substantial proportion of pneumonia deaths in TB-endemic countries. Childhood TB should be given higher priority: we need to identify children at greatest risk of TB disease and death and make more use of tools such as active case-finding and preventive therapy. TB is a preventable and treatable disease from which no child should die.

Laboratory Diagnosis of Mycobacterium tuberculosis Infection and Disease in Children

Diagnosis of tuberculosis in children is challenging; even with advanced technologies, the diagnosis is often difficult to confirm microbiologically in part due to the paucibacillary nature of the disease. Clinical diagnosis lacks standardization, and traditional and molecular microbiologic methods lack sensitivity, particularly in children. Immunodiagnostic tests may improve sensitivity, but these tests cannot distinguish tuberculosis disease from latent infection and some lack specificity. While molecular tools like Xpert MTB/RIF have advanced our ability to detect Mycobacterium tuberculosis and to determine antimicrobial resistance, decades old technologies remain the standard in most locales. Today, the battle against this ancient disease still poses one of the primary diagnostic challenges in pediatric laboratory medicine.