"Induced sputum versus gastric lavage for the diagnosis of pulmonary tuberculosis in children"

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.

Clinical Profile of Pediatric Tuberculosis in a Tertiary Hospital in Northeast India: A Retrospective Analysis

Context Tuberculosis (TB) is India's major public health problem. The profile of childhood TB in the northeast region of India is still limited. Aim To analyze the clinical, radiological, and bacteriological profiles of children with TB at a tertiary health care facility. Materials and methods A three years retrospective descriptive analysis of children admitted to a tertiary centre with TB before the introduction of cartridge-based nucleic acid amplification test (CBNAAT) for testing. Children below 18 years who were admitted from 2012 to 2014 and were diagnosed with TB were included. Relevant data were extracted in a predesigned format and entered into a Microsoft Excel sheet. Descriptive statistic was used for analysis. The results of variables are given in proportions and means and a Chi-square test was done for the test of significance using Epi-info tools. The study was done after getting ethical approval from the institute. Results A total of 150 children were included in the analysis with a Male: Female ratio of 1.1:1. A majority of the cases were under five years (n=46) and 11 to 15 years old (n=45) with a mean age of 9.3 ± 4.4 years. Fever was a common presentation (70%). Disseminated TB was seen in 31.3%, isolated central nervous system (CNS) TB was found in 30.6%, and all CNS TB with dissemination was found in 46 cases (40.7%) making extra-pulmonary TB a common finding in our study (83.3%). Isolated pulmonary TB was seen in 16.7% and total pulmonary cases along with dissemination was seen in 60 cases (40%). A bacteriological diagnosis was made in 23%. Overall mortality was 9.3%, out of which mortality in CNS TB was 13% with a p-value of 0.004 as compared to mortality other than CNS TB which was significant and mortality in under-five years was significant with a p-value of 0.001. Conclusions Pulmonary and extra-pulmonary were both causes of admission in the pediatric age group. We found that extra-pulmonary TB was the most common cause of admission in children, with CNS manifestation and disseminated TB, being the most common presentations and significant mortality was seen in under-five years and in children diagnosed with CNS TB.

Stool specimen for diagnosis of pulmonary tuberculosis in adults: a systematic review

OBJECTIVE

To assess the diagnostic accuracy of stool specimens to diagnose pulmonary tuberculosis (PTB) in adults.

DESIGN

Systematic review.

DATA SOURCES

MEDLINE (Ovid), Embase (Ovid), Web of Science and the Cochrane database were searched from inception to 9 March 2023-10 March 2023 using a comprehensive search strategy; reference lists of selected articles and relevant review articles were manually searched.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies in English reporting diagnostic performance of stool specimens against respiratory specimens using mycobacterial culture or smear microscopy or Xpert assay to diagnose PTB in adults were eligible for this systematic review.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently screened the retrieved citations and extracted data. The risk of bias and applicability of results were assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Narrative data synthesis was performed.

RESULTS

A total of 1658 citations were screened, and 28 full-text articles were assessed. Nine studies met the inclusion criteria. The reported sensitivity and specificity of stool culture varied between 21.4% and 63.9%, and 61.5% and 100%, respectively. In stool smear microscopy, sensitivities and specificities ranged from 12.1% to 53.9%, and from 79.5% to 100%, respectively. The reported sensitivities of PCR assays, including Xpert assays, ranged from 69.7% to 100%, with specificities ranging from 69.8% to 100%. Most of the studies had a low risk of bias and a low applicability concern in all domains.

CONCLUSION

This systematic review could not conclude on the diagnostic accuracy of stool specimens for PTB diagnosis in adults. Further studies are required to evaluate the accuracy of stool specimens in adults to enable meta-analyses in updates of this review as well as other systematic reviews.

PROSPERO REGISTRATION NUMBER

CRD42021245203.

Use of uncoated magnetic beads to capture Mycobacterium smegmatis and Mycobacterium avium paratuberculosis prior detection by mycobacteriophage D29 and real-time-PCR

Uncoated tosyl-activated magnetic beads were evaluated to capture Mycobacterium smegmatis and Mycobacterium avium subspecies paratuberculosis (MAP) from spiked feces, milk, and urine. Centrifugation and uncoated magnetic beads recovered more than 99% and 93%, respectively, of 1.68 × 10⁷ CFU/mL, 1.68 × 10⁶ CFU/mL and 1.68 × 10⁵ CFU/mL M. smegmatis cells resuspended in phosphate buffer saline. The use of magnetic beads was more efficient to concentrate cells from 1.68 × 10⁴ CFU/mL of M. smegmatis than centrifugation. Likewise, the F57-qPCR detection of MAP cells was different whether they were recovered by beads or centrifugation; cycle threshold (Ct) was lower (p < 0.05) for the detection of MAP cells recovered by beads than centrifugation, indicative of greater recovery. Magnetic separation of MAP cells from milk, urine, and feces specimens was demonstrated by detection of F57 and IS900 sequences. Beads captured no less than 10⁹ CFU/mL from feces and no less than 10⁴ CFU/mL from milk and urine suspensions. In another detection strategy, M. smegmatis coupled to magnetic beads were infected by mycobacteriophage D29. Plaque forming units were observed after 24 h of incubation from urine samples containing 2 × 10⁵ and 2 × 10³ CFU/mL M. smegmatis. The results of this study provide a promising tool for diagnosis of tuberculosis and Johne's disease.

Stool specimen for diagnosis of pulmonary tuberculosis in adults: protocol for a systematic review and meta-analysis

INTRODUCTION

Tuberculosis (TB) continues to be a significant health burden, most commonly affecting the lungs and referred to as pulmonary TB (PTB). Diagnostic techniques of PTB primarily rely on expectorated sputum samples. However, the diagnostic yields are often hindered due to insufficient volume and quality of the sputum specimens. Moreover, some individuals are unable to provide sputum samples due to scanty sputum production or difficulty in coughing up and require an invasive procedure to obtain a respiratory sample, such as bronchoscopic or gastric aspiration. Thus, challenges in the acquisition of respiratory specimens warrant an alternate specimen. Therefore, this systematic review aims to evaluate the diagnostic accuracy of a stool specimen for the diagnosis of PTB in adults.

METHODS AND ANALYSIS

We will search MEDLINE (Ovid), Embase (Ovid), Web of Science and Cochrane database from inception to April 2021 using a comprehensive search strategy. Two reviewers will independently perform screening, data extraction and quality assessment. The risk of bias assessment and applicability of results of eligible studies will be performed using the Quality of Diagnostic Accuracy Studies-2 tool. Bivariate random-effects models will be performed to calculate pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio and diagnostic odds ratio along with 95% CI of stool specimen for each reported diagnostic method against any of the reference standard test (ie, mycobacterial culture or smear microscopy or Xpert assay using respiratory specimens). Heterogeneity between studies will be assessed by I² statistics and Q statistic of the χ² test.

ETHICS AND DISSEMINATION

The results will be disseminated through publishing in a peer-reviewed medical journal and public presentations in relevant national and international conferences. As this is a systematic review of publicly available data, ethics approval is not required.

PROSPERO REGISTRATION NUMBER

CRD42021245203.

Immunological Aspects of Diagnosis and Management of Childhood Tuberculosis

The diagnosis of tuberculosis (TB) in children is difficult because of the low sensitivity and specificity of traditional microbiology techniques in this age group. Whereas in adults the culture of Mycobacterium tuberculosis (M. tuberculosis), the gold standard test, detects 80% of positive cases, it only detects around 30-40% of cases in children. The new methods based on the immune response to M. tuberculosis infection could be affected by many factors. It is necessary to evaluate the medical record, clinical features, presence of drug-resistant M. tuberculosis strains, comorbidities, and BCG vaccination history for the diagnosis in children. There is no ideal biomarker for all TB cases in children. A new strategy based on personalized diagnosis could be used to evaluate specific molecules produced by the host immune response and make therapeutic decisions in each child, thereby changing standard immunological signatures to personalized signatures in TB. In this way, immune diagnosis, prognosis, and the use of potential immunomodulators as adjunct TB treatments will meet personalized treatment.

Which sample type is better for Xpert MTB/RIF to diagnose adult and pediatric pulmonary tuberculosis?

Objective: This review aimed to identify proper respiratory-related sample types for adult and pediatric pulmonary tuberculosis (PTB), respectively, by comparing performance of Xpert MTB/RIF when using bronchoalveolar lavage (BAL), induced sputum (IS), expectorated sputum (ES), nasopharyngeal aspirates (NPAs), and gastric aspiration (GA) as sample.

Methods: Articles were searched in Web of Science, PubMed, and Ovid from inception up to 29 June 2020. Pooled sensitivity and specificity were calculated, each with a 95% confidence interval (CI). Quality assessment and heterogeneity evaluation across included studies were performed.

Results: A total of 50 articles were included. The respective sensitivity and specificity were 87% (95% CI: 0.84–0.89), 91% (95% CI: 0.90–0.92) and 95% (95% CI: 0.93–0.97) in the adult BAL group; 90% (95% CI: 0.88–0.91), 98% (95% CI: 0.97–0.98) and 97% (95% CI: 0.95–0.99) in the adult ES group; 86% (95% CI: 0.84–0.89) and 97% (95% CI: 0.96–0.98) in the adult IS group. Xpert MTB/RIF showed the sensitivity and specificity of 14% (95% CI: 0.10–0.19) and 99% (95% CI: 0.97–1.00) in the pediatric ES group; 80% (95% CI: 0.72–0.87) and 94% (95% CI: 0.92–0.95) in the pediatric GA group; 67% (95% CI: 0.62–0.72) and 99% (95% CI: 0.98–0.99) in the pediatric IS group; and 54% (95% CI: 0.43–0.64) and 99% (95% CI: 0.97–0.99) in the pediatric NPA group. The heterogeneity across included studies was deemed acceptable.

Conclusion: Considering diagnostic accuracy, cost and sampling process, ES was a better choice than other sample types for diagnosing adult PTB, especially HIV-associated PTB. GA might be more suitable than other sample types for diagnosing pediatric PTB. The actual choice of sample types should also consider the needs of specific situations.

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.

Combined Use of Gastric Aspirate and Induced Sputum Increases the Microbiological Diagnosis of Tuberculosis in Children

Objective Diagnosis of pulmonary tuberculosis (PTB) in pediatrics is a challenge due to the paucibacillary condition of the disease in this population, low sputum expectoration, and diverse unspecific symptomatology. Mycobacterial isolation through culture remains a priority. The objective of this study is to explore gastric aspirates and induced sputum techniques in the pediatric population for positivity on mycobacterial cultures.

Methods In this observational analytical study, two temporal groups were evaluated. A comparison of the isolation rate defined as positive culture confirmation by gastric aspirate (GA), induced sputum (IS), or combination of these both techniques in children under 10 years of age. The study included 86 children, 37 in the first evaluated study group and 49 in the second group.

Discussion Culture positivity was 10.8 and 30.6% for the first and second case series, respectively. These findings showed that the combination of GA and IS in two consecutive days yielded a significantly higher detection rate to confirm pulmonary tuberculosis by culture.

Conclusion The combination of GA plus IS samples for collection of M. tuberculosis culture can be a useful, nonexpensive, and safe diagnostic tool in low- and middleincome countries to diagnose tuberculosis in children.

Diagnostic accuracy of molecular detection of Mycobacterium tuberculosis in pediatric stool samples: A systematic review and meta-analysis

BACKGROUND

Stool is a promising specimen option to diagnose pediatric tuberculosis (TB), but studies have reported a wide range of test sensitivities. We conducted a meta-analysis to assess the accuracy of Xpert MTB/RIF or 'in-house' molecular tests on stool samples against culture or Xpert MTB/RIF on respiratory samples or clinically-diagnosed unconfirmed TB and aimed to identify factors that contribute to the heterogeneity of reported sensitivity.

METHODS

We searched EMBASE and Pubmed databases and conference abstract books for studies reporting molecular stool testing against a clinical or microbiological reference standard among children.

RESULTS

We identified 16 studies that included 2,481 children in stool test analyses. Pooled specificity was 98% [95%CI: 96-99], pooled sensitivity was 57% [95%CI: 40-72] against culture and 3% [95%CI: 2-6] among children with clinically-diagnosed, unconfirmed TB. There was much heterogeneity. Sensitivity was higher among children with a smear-positive sputum test. Rifampin resistance in stool was reported in two studies and detected in 5/14 children (36%).

CONCLUSION

Our results suggest molecular stool tests have potential as diagnostic rule-in tests, but it is challenging to optimize sensitivity due to between-study variation in methodology and test procedures. Therefore, we recommend future research with rigorous study design and standardized results reporting.

Soluble urokinase-type plasminogen activator receptor as a biomarker of treatment response in childhood tuberculosis

Background

Childhood tuberculosis (TB) is a major health problem worldwide, especially in developing countries. In 2015, there are estimated 950,000 cases of childhood TB. Since most TB in children is paucibacillary, this gives rise not only to problem in diagnosing but also in monitoring the response to anti-TB treatment as well. Soluble urokinase-type plasminogen activator receptor (suPAR), a glycosylphosphatidylinositol-linked membrane protein of various cells of immune system, is one of the potential biomarkers to be used in the management of TB. The objective of this study is to study the decrease of serum suPAR level after anti-TB treatment in children with TB and its association with patient characteristics.

Methods

We conducted a prospective study on children suspected of having TB due to a history of contact with active TB case and symptoms such as coughing, fever, and enlarged lymph nodes. The diagnosis of TB is established by history, physical examination including anthropometric examination. Tuberculin skin test using PPD RT-23 and interferon-gamma releasing assay with Quantiferon TB-Gold Plus was performed. Chest X-rays were read by two independent radiologists. Microbiological examination was performed using microscopic examination and Xpert MTB/RIF. The level of suPAR before and after anti-TB treatment was examined with the Elisa method.

Results

There was no significant difference of serum suPAR levels before and after anti-TB treatment (mean 0.71 [standard deviation 0.585] ng/mL; P = 0.072). There was no association between ages (P = 0.112), nutritional status (P = 0.228), diagnosis of pulmonary or extrapulmonary TB (P = 0.956), and radiological feature (P = 0.810) with serum suPAR levels decrease.

Conclusion

There is no suPAR serum level decrease 2 months after treatment with anti-TB and there is no association with age, nutritional status, pulmonary or extrapulmonary TB diagnosis, and radiological feature.

[Tuberculosis in indigenous children and adolescents in Brazil: factors associated with death and treatment dropout]

The study aimed to describe clinical and sociodemographic characteristics, estimate incidence, and analyze factors associated with dropout and death during treatment of TB cases reported in indigenous children and adolescents in Brazil from 2006 to 2016. A historical case series was performed on incidence according to age bracket and major geographic region, and multinomial logistic regression was used to explain factors associated with treatment dropout and death. Of the 2,096 reported cases, 88.2% evolved to cure, 7.2% dropped out of treatment, and 4.6% evolved to death. There was a predominance of cases in boys 15-19 years of age and a higher proportion of deaths (55.7%) in children < 4 years. Considering indigenous children and adolescents with TB in Brazil as a whole, mean incidence was 49.1/100,000, ranging from 21.5/100,000 to 97.6/100,000 in the Northeast and Central, respectively. Cases with insufficient and irregular follow-up showed higher odds of dropout (OR = 11.1; 95%CI: 5.2-24.8/OR = 4.4; 95%CI: 1.9-10.3) and death (OR = 20.3; 95%CI: 4.9-84.9/OR = 5.1; 95%CI: 1.2-22.7). Cases in retreatment (OR = 2.4; 95%CI: 2.08-8.55) and with HIV coinfection (OR = 8.2; 95%CI: 2.2-30.9) were also associated with dropout. Extrapulmonary (OR = 1.8; 95%CI: 1.1-3.3) and mixed clinical forms (OR = 5.6; 95%CI: 2.8-11.4), age < 4 years (OR = 3.1; 95%CI: 1.5-6.4), and cases from the North (OR = 2.8; 95%CI: 1.1-7.1) and Central (OR = 2.8; 95%CI: 1.1-7.0) were associated with death. TB control in indigenous children and adolescents cannot be achieved without investments in research and development and without reducing social inequalities.

GeneXpert of stool versus gastric lavage fluid for the diagnosis of pulmonary tuberculosis in severely ill adults

PURPOSE

Stool is an alternative specimen matrix for tuberculosis (TB) tests, because Mycobacterium tuberculosis (MTB) can be swallowed and detected in the samples from digestive tract. We aimed to assess the performance of GeneXpert on stool and gastric lavage fluid (GALF) in diagnosing TB among patients with severe pulmonary TB.

METHODS

We enrolled adults with suspected pulmonary TB who were unable to produce sputum at visit between January 2016 and June 2018. Bacteriological samples consisted of one transtracheal aspirate sputum specimen, one stool specimen and/or one gastric lavage fluid specimen. Bacterial culture of transtracheal aspirate sputum provided the gold standard.

RESULTS

Of 65 individuals recruited for analysis, MGIT culture identified the presence of MTB in 32 samples. Overall, 29 of 32 stool samples from culture-positive cases were detected by the GeneXpert test, demonstrating a sensitivity of 90.6%. For GALF, 13 patients were detected as infected with MTB by GeneXpert, yielding a sensitivity of 56.5%. The statistical analysis revealed that GeneXpert showed significantly better sensitivity in detecting MTB from stool samples than GALF samples (P = 0.003). Among individuals with GeneXpert-positive stool, the percentage of individuals with comorbid diabetes was significantly higher than among individuals with GeneXpert-negative stool (19.4% vs. 2.9%, P = 0.034).

CONCLUSIONS

In conclusion, our data reveal that GeneXpert provides a higher detection rate on stool compared to GALF, indicating stool should be considered as an alternative for adult TB patients unable to produce sputum. Individuals with diabetes are more likely to have positive GeneXpert stool than nondiabetic individuals.

Tuberculosis in children from diagnosis to decision to treat

SETTING

Confirmation of tuberculosis (TB) in children is difficult, so clinicians use different procedures when deciding to treat.

OBJECTIVE

Identify criteria to initiate and maintain TB treatment in children younger than 5 years-old, without diagnosis confirmation.

DESIGN

A web-based survey was distributed by email to the corresponding authors of journal articles on childhood TB. The observations were clustered into disjoint groups, and analyzed by Ward's method.

RESULTS

We sent out 260 questionnaires and received 64 (24.6%) responses. Forty-six respondents (71.9%) said that microbiological confirmation was not important for initiation of anti-TB treatment, and that the epidemiological context and signs/symptoms suggestive of disease were most important. Sixty-one respondents (95.3%) said that the decision to continue therapy was mainly dependent on clinical improvement. A cluster of older respondents (median age: 52 years-old) who were active at a hospital or primary health care centre placed the most value on immunological test results and chest X-rays. A cluster of younger respondents (median age: 38 years-old) who were less experienced in management of TB placed more value on Interferon Gamma Release Assay (IGRA) results and chest computed tomography (CT) scans. A cluster of respondents with more experience in treating TB and working at specialized TB centres placed greater value on the clinical results and specific radiological alterations ("tree-in-bud" pattern and pleural effusion).

CONCLUSION

TB management varied according to the age, work location and experience of the clinicians. It is necessary to establish standardized guidelines used for the diagnosis and decision to treat TB in children.

Tuberculosis in Infants and Children

One million children develop tuberculosis disease each year, and 210,000 die from complications of tuberculosis. Childhood tuberculosis is very different from adult tuberculosis in epidemiology, clinical and radiographic presentation, and treatment. This review highlights the many unique features of childhood tuberculosis, with special emphasis on very young children and adolescents, who are most likely to develop disease after infection has occurred.

Gastric specimens for diagnosing tuberculosis in adults unable to expectorate in Rawalpindi, Pakistan

Setting: Adult pulmonary tuberculosis (TB) patients unable to expectorate quality sputum represent a diagnostic challenge. A private hospital in Pakistan routinely performs gastric aspiration in adults with difficulties expectorating. Objective: To assess the usefulness of gastric specimens (GS) in diagnosing pulmonary TB (PTB) and drug-resistant TB in adult presumptive TB patients unable to expectorate, and to compare the diagnostic yield and sensitivity of smear, culture and the Xpert^® MTB/RIF assay. Design: This was a comparative cross-sectional study based on retrospective record review. Results: Of 900, 885 and 877 GS tested by smear, Xpert and culture, respectively, interpretable results were obtained for respectively 900 (100%), 859 (97.1%) and 754 (86.0%), with a diagnostic yield of respectively 23.6%, 30.3% and 24.9%. The yield was significantly higher for Xpert in previously treated patients. There were 313 patients with definite TB, defined as positive on Xpert and/or culture. The 82.8% sensitivity of Xpert was significantly higher than that of smear (61.0%) and culture (67.8%). Conclusion: GS obtained by aspiration under routine programme conditions is useful for detecting TB and drug-resistant TB in adult patients unable to expectorate. Xpert, with its rapid testing, high proportion of interpretable results and better sensitivity, can substantially improve the diagnosis of bacteriologically confirmed TB and rifampicin resistance.

Diagnosis and treatment of paediatric tuberculosis: An insight review

Tuberculosis (TB) is a major public health problem, invading all age groups world-wide. It is an opportunistic infection affecting the individuals alone or with co-infections. Childhood TB is a neglected aspect and a significant health problem in epidemic areas. It constitutes more than 20% of TB incidence. Pediatric TB exists in the shadow of adult TB. The clinicians concentrate on pulmonary manifestation of TB, whereas it is a major problem in both pulmonary and extra-pulmonary infections. The rate of infection with this disease is mostly associated with poverty, social disruption and human immunodeficiency virus (HIV) infection. The diagnosis of extra-pulmonary TB (EPTB) is more difficult than pulmonary TB (PTB). Delayed diagnosis and executive treatment contribute to increase in the mortality rate in endemic areas. This article provides the evidence-based simple and safe screening method, indicating rapid, highly sensitive and specific diagnostic tests for pulmonary and EPTB in children. The most important aspect of treatment is the correct course of anti-tubercular drugs. This review serves the purpose of quick reference for microbiologists, epidemiologists, academicians, students and researchers. It provides guidance regarding early diagnosis and treatment accuracy of pediatric TB.

Stool Xpert® MTB/RIF test for the diagnosis of childhood pulmonary tuberculosis at primary clinics in Zimbabwe

OBJECTIVE

To evaluate the diagnostic performance of Xpert® MTB/RIF on stool samples from children with clinical suspicion of pulmonary tuberculosis (PTB) at primary care clinics.

DESIGN

A cross-sectional diagnostic evaluation enrolling 5-16 year olds from whom one induced sputum (IS) sample was tested for microbiological TB confirmation. Results of a single stool sample tested using Xpert were compared against microbiologically confirmed TB, defined as a positive result on sputum microscopy and/or culture and/or IS Xpert.

RESULTS

Of 222 children enrolled, 218 had complete microbiological results. The median age was 10.6 years (interquartile range 8-13). TB was microbiologically confirmed in 19/218 (8.7%) children. Of these, respectively 5 (26%), 9 (47%) and 15 (79%) were smear-, culture- and IS Xpert-positive. Stool Xpert was positive in 13/19 (68%) microbiologically confirmed cases and 4/199 (2%) microbiologically negative cases. Stool Xpert detected 76.9% (10/13) of human immunodeficiency virus (HIV) infected and 50% (3/6) of non-HIV-infected children with microbiologically confirmed TB (P = 0.241).

CONCLUSION

Stool Xpert is a potential alternative screening test for children with suspected TB if sputum is unavailable. Strategies to optimise the diagnostic yield of stool Xpert assay need further study.

Prevalence of and risk factors for pulmonary tuberculosis among newly diagnosed HIV-1 infected Nigerian children

INTRODUCTION

Studies on the prevalence of and risk factors for tuberculosis (TB) among newly diagnosed human immunodeficiency virus (HIV)-infected children in sub-Saharan Africa are scarce and in Nigeria there is paucity of reported data. We determined the prevalence of and risk factors for pulmonary TB (PTB) in newly diagnosed (treatment-naïve) HIV-1 infected children at the pediatric HIV clinic of the Jos University Teaching Hospital (JUTH) in Nigeria.

METHODS

We performed a retrospective analysis of 876 children, aged 2 months - 13 years, diagnosed with HIV-1 infection between July 2005 and December 2012, of which 286 were diagnosed with PTB at presentation after TB screening. The study site was the AIDS Prevention Initiative in Nigeria (APIN)-supported Pediatric HIV clinic at JUTH, Jos. A multivariate forward logistic regression modelling was used to identify risk factors for PTB-HIV co-infection.

RESULTS

The prevalence of PTB-HIV co-infection was 32% (286/876). Severe immunosuppression (SI) and World Health Organization (WHO) HIV clinical stage 3/4 were identified as independent risk factors for PTB-HIV co-infection in HIV infected children. The odds of PTB-HIV co-infection was increased two-fold in HIV-infected children with WHO clinical stage 3/4 compared to those with stage 1/2 (adjusted odds ratio (AOR) 1.76 [1.31-2.37], p<0.001) and 1.5-fold in children with SI compared to those without SI (AOR 1.52 [1.12-2.06], p=0.007).

CONCLUSION

In our setting, the burden of PTB was high among newly diagnosed HIV-infected children, and late WHO HIV clinical stage and severe immunosuppression were associated with PTB-HIV co-infection. Therefore there is a clear need to improve strategies for early diagnosis of both HIV and PTB to optimize clinical outcomes.

Rapid culture-based diagnosis of pulmonary tuberculosis in developed and developing countries

Culturing Mycobacterium tuberculosis remains the gold standard for the laboratory diagnosis of pulmonary tuberculosis, with 9 million new cases and 1.5 million deaths mainly in developing countries. Reviewing data reported over 20 years yields a state-of-the-art procedure for the routine culture of M. tuberculosis in both developed and developing countries. Useful specimens include sputum, induced sputum, and stools collected in quaternary ammonium preservative-containing sterile cans. The usefulness of other non-invasive specimens remains to be evaluated. Specimens can be collected in a diagnosis kit also containing sampling materials, instructions, laboratory requests, and informed consent. Automated direct LED fluorescence microscopy after auramine staining precedes inoculation of an egg-lecithin-containing culture solid medium under microaerophilic atmosphere, inverted microscope reading or scanning video-imaging detection of colonies and colonies identification by recent molecular methods. This procedure should result in a diagnosis of pulmonary tuberculosis as fast as 5 days. It may be implemented in both developed and developing countries with automated steps replaceable by manual steps depending on local resources.

Newer Diagnostic Tests for Pulmonary Tuberculosis in Children

It has been well recognized that the diagnosis of pulmonary tuberculosis in children is often compromised by non-specific symptoms, paucibacillary nature of the disease, and the difficulty in collecting the specimen. Consequently, most tuberculosis cases in children are not confirmed, due to which the estimation of the global burden of tuberculosis in children may be inaccurate. There has also been a common misperception that diagnosis of tuberculosis and collecting respiratory specimen in children is always difficult. Because of this, microbiological confirmation of tuberculosis in young children is not routinely attempted in most endemic areas. With the emergence of HIV-related tuberculosis disease and drug-resistant tuberculosis, the availability of accurate, rapid and child friendly diagnostic tools to identify Mycobacterium tuberculosis in respiratory specimen are urgently required in endemic settings. There have been a large number of studies evaluating new diagnostic tests for tuberculosis in the past decade, but few have been evaluated in children. This review will address the developments in respiratory specimen collection and laboratory diagnostic tests of tuberculosis, with a focus on those that have been evaluated in children.

What steps do we need to take to improve diagnosis of tuberculosis in children?

Tuberculosis still represents a big global public health challenge. The diagnosis of tuberculosis and the differentiation between active and latent tuberculosis remain difficult, particularly in childhood, because of the lack of a gold standard test for diagnosis. In the last decade, novel diagnostic assays have been developed. Among immunologic tests, new assays based on the measurement of different cytokines released by specific T cells in response to Mycobacterium tuberculosis antigens, other than INF-γ, have been investigated. Promising results rely on nucleic acid amplification techniques, also able to detect drugs resistance. Innovative research fields studied the modifications of CD27 expression in T cells as well as different host gene expression in response to M. tuberculosis. Further studies are needed to assess the diagnostic value and the accuracy of these new assays.

Tuberculosis in children

Tuberculosis (TB) in children is a neglected aspect of the TB epidemic despite it constituting 20% or more of all TB cases in many countries with high TB incidence. Childhood TB is a direct consequence of adult TB but remains overshadowed by adult TB because it is usually smear-negative. Infants and young children are more likely to develop life-threatening forms of TB than older children and adults due to their immature immune systems. Therefore, prompt diagnoses are extremely important although difficult since clinical and radiological signs of TB can be non-specific and variable in children. Despite undeniable advances in identifying definite, probable, or possible TB markers, pediatricians still face many problems when diagnosing TB diagnosis. Moreover, curing TB can be difficult when treatment is delayed and when multi-drug resistant (MDR) pathogens are the cause of the disease. In these cases, the prognosis in children is particularly poor because MDR-TB treatment and treatment duration remain unclear. New studies of diagnostic tests and optimal treatment in children are urgently needed with the final goal of developing an effective anti-TB vaccine.