Recent advances in the diagnosis and treatment of childhood tuberculosis

Drug resistant tuberculosis: Implications for transmission, diagnosis, and disease management

Drug resistant tuberculosis contributes significantly to the global burden of antimicrobial resistance, often consuming a large proportion of the healthcare budget and associated resources in many endemic countries. The rapid emergence of resistance to newer tuberculosis therapies signals the need to ensure appropriate antibiotic stewardship, together with a concerted drive to develop new regimens that are active against currently circulating drug resistant strains. Herein, we highlight that the current burden of drug resistant tuberculosis is driven by a combination of ongoing transmission and the intra-patient evolution of resistance through several mechanisms. Global control of tuberculosis will require interventions that effectively address these and related aspects. Interrupting tuberculosis transmission is dependent on the availability of novel rapid diagnostics which provide accurate results, as near-patient as is possible, together with appropriate linkage to care. Contact tracing, longitudinal follow-up for symptoms and active mapping of social contacts are essential elements to curb further community-wide spread of drug resistant strains. Appropriate prophylaxis for contacts of drug resistant index cases is imperative to limit disease progression and subsequent transmission. Preventing the evolution of drug resistant strains will require the development of shorter regimens that rapidly eliminate all populations of mycobacteria, whilst concurrently limiting bacterial metabolic processes that drive drug tolerance, mutagenesis and the ultimate emergence of resistance. Drug discovery programs that specifically target bacterial genetic determinants associated with these processes will be paramount to tuberculosis eradication. In addition, the development of appropriate clinical endpoints that quantify drug tolerant organisms in sputum, such as differentially culturable/detectable tubercle bacteria is necessary to accurately assess the potential of new therapies to effectively shorten treatment duration. When combined, this holistic approach to addressing the critical problems associated with drug resistance will support delivery of quality care to patients suffering from tuberculosis and bolster efforts to eradicate this disease.

Childhood Cancers Misdiagnosed as Tuberculosis in a High Tuberculosis Burden Setting

BACKGROUND

Tuberculosis (TB) and childhood cancers have overlapping presentations and malignancies may be misdiagnosed as TB in high TB-burden settings.

METHODS

This retrospective study investigated the diagnosis of TB in children with cancer registered in the Tygerberg Hospital Childhood Tumor Registry from 2008 to 2018. We studied children on anti-tuberculosis treatment (ATT) at cancer diagnosis or diagnosed with TB within 1 month of cancer diagnosis. We describe the circumstances and extent of this misdiagnosis, quantify the delay in therapy and document the outcomes of these children.

RESULTS

Twenty-seven of 539 (5%) children in the registry started ATT before cancer diagnosis. Both pulmonary and extrapulmonary TB complicated the cancer diagnosis. Of the 27 patients on ATT at cancer diagnosis, 22 (81%) had contact with a TB case and in 6 of 12 children (50%) a tuberculin skin test was positive. At cancer diagnosis, 16/27 (59%) children had chest radiograph changes interpreted as TB with 11/27 (41%) regarded as suggestive of TB on expert review. The median diagnostic delay between TB and cancer diagnoses was 25 days (interquartile range 3.5-58). Of 539 children with cancer, 204 (38%) died of cancer, including 18/30 (60%) children on ATT at cancer diagnosis or diagnosed with TB within 1 month of cancer diagnosis (odds ratio 2.6; 95% confidence interval: 1.2-5.4; P = 0.012).

CONCLUSIONS

The clinical and radiologic overlap of TB and cancer causes diagnostic confusion in a significant number of children with cancer and may contribute to increased mortality.

ESAT-6 and Ag85A Synthetic Peptides as Candidates for an Immunodiagnostic Test in Children with a Clinical Suspicion of Tuberculosis

Background

Tuberculosis (TB) is being underdetected in children as most are smear-negative. This work was aimed at evaluating ESAT-6 and Ag85A synthetic peptides' serodiagnostic potential for diagnosing children having a clinical suspicion of TB.

Methods

The study involved 438 children: 77 Creole nonindigenous (13 suspected of having TB and 64 healthy ones) and 361 Warao indigenous children (39 suspected of TB and 322 healthy children). The approach's diagnostic information was compared using operational characteristics and receiver-operating characteristic (ROC) curves.

Results

Ag85A P-29879 had 94.6% sensitivity (AUC = 0.741: 0.651 to 0.819 95% CI) in indigenous children. ESAT-6 P-12036 and P-12037 had 100% and 92.3% of sensitivity (AUC = 0.929: 0.929: 0.846 to 0.975 95% CI and 0.791: 63.9 to 98.7 95% CI, respectively) in Creole children. ESAT-6 peptides also allowed a differentiation between children with TB and healthy ones.

Conclusions

Further validation of this approach could lead to developing a complementary tool for rapid TB diagnosis in children.

Old biomarkers in tuberculosis management: are they still useful? a systematic review

Introduction: The diagnosis of childhood tuberculosis (TB) can be challenging, given the lack of a gold standard test. Several new biomarkers have been studied for research purposes, but despite encouraging results, they are not used in clinical practice yet. Old biomarkers can be valuable tools in TB management. We conducted a systematic review to provide an update on their possible usefulness in TB patients.Areas covered: C-reactive protein could be useful to rule out TB, due to its high negative predictive value. Moreover, ferritin and erythrocyte sedimentation rates were found to be higher in TB patients with positive sputum smears. The lack of biomarkers decreases during an appropriate treatment course, indicating a poor response to treatment, seems to be correlated with a higher risk of death. Finally, procalcitonin and C-reactive protein seems to be useful in the differential diagnosis with pneumonia.Expert opinion: Old biomarkers are point-of-care tests, cheap and easily interpretable. These characteristics make them particularly useful, especially in TB endemic areas, to better manage patients with TB. Further studies performed in children are essential to implement the use of old biomarkers as diagnostic and prognostic tests.

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.

HIV-associated tuberculosis

Tuberculosis (TB) remains a leading cause of morbidity and mortality among people living with HIV. HIV-associated TB disproportionally affects African countries, particularly vulnerable groups at risk for both TB and HIV. Currently available TB diagnostics perform poorly in people living with HIV; however, new diagnostics such as Xpert Ultra and lateral flow urine lipoarabinomannan assays can greatly facilitate diagnosis of TB in people living with HIV. TB preventive treatment has been underutilized despite its proven benefits independent of antiretroviral therapy (ART). Shorter regimens using rifapentine can support increased availability and scale-up. Mortality is high in people with HIV-associated TB, and timely initiation of ART is critical. Programs should provide decentralized and integrated TB and HIV care in settings with high burden of both diseases to improve access to services that diagnose TB and HIV as early as possible. The new prevention and diagnosis tools recently recommended by WHO offer an immense opportunity to advance our fight against HIV-associated TB. They should be made widely available and scaled up rapidly supported by adequate funding with robust monitoring of the uptake to advance global TB elimination.

How do private practitioners in Pakistan manage children suspected having tuberculosis? A cross sectional study

Background

In Pakistan, private providers provide a large portion of health care, including for tuberculosis (TB). All TB patients are supposed to be reported to the National Tuberculosis Program (NTP), which provides drugs free of charge in addition to monitoring, supervision, and support. However, diagnosis of TB in children is difficult. We aimed to assess the private health care providers’ investigation practices and management of childhood TB.

Methods

We used a cross-sectional study, which was based on a national survey measuring under-reporting of children with TB in 12 selected districts in Pakistan from April–June, 2016. We explored the practices of the private health care providers, including the health care workers i.e. general practitioners, pediatricians, pulmonologists and chest specialists, who were involved in the diagnosis of TB in children under 15 years for investigating and managing children suspected having TB.

Results

Among 6519 presumptive child TB cases, a total of 5193(79.7%) children under 15 years were diagnosed as TB by private health care providers during second quarter, 2016. Only 187(2.9%) were notified to NTP. The majority of presumptive child TB cases reported cough, fever, and failure to thrive; few had TB contacts with pulmonary TB patients. Failure to thrive, loss of body weight and absence of BCG (Bacillus Calmette–Guérin) scar was more common in female children. Private providers relied on chest X-ray in 46.1%, while tuberculin skin test and Gene-Xpert MTB/RIF testing was little utilized. Bacteriological confirmation was present in 7.6%, and clinical assessment was the only basis for diagnosis in 39.3%. Of children with presumptive TB, only 955(14.6%) children were treated by private provider, while 3121(47.9%) cases were referred for diagnosis and 2443(37.5%) were referred after diagnosis for treatment; among all the referred, 3812(68.5%) were sent for investigations to District TB Centre (NTP).

Conclusion

This study showed that many private providers referred children suspected having TB to laboratories for further diagnosis, but the cases identified in these investigations were often not notified to the NTP. This problem could be resolved by strengthening the referral linkages between private health providers, NTP laboratories and treatment centres through capacity building and training of their staff.

Performance of a lymphocyte t interferon gamma test (Quantiferon-TB gold in tube) in the diagnosis of active tuberculosis in HIV-infected children

OBJECTIVE

Evaluate the performance of QuantiFERON ® -TB Gold In-Tube test (QFT-GIT), to improve the diagnosis of active tuberculosis (TB) in Human Immuno-Deficiency Virus (HIV)-infected children.

METHOD

Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) of QFT-GIT were assessed in 58/63 HIV-infected children who were suspected of having TB.

RESULTS

Sensitivity of QFT-GIT was 20.69%, specificity 96.55%, PPV/NPV respectively 85.71% and 54.90%.

CONCLUSION

QFT-GIT appears to be of little contribution to the diagnosis of active TB in children living with HIV in a TB-endemic country.

The epidemiology of pulmonary tuberculosis in children in Mainland China, 2009-2015

OBJECTIVE

To describe the incidence and epidemiological characteristics of child pulmonary tuberculosis (PTB) notified to the Chinese Center for Disease Control and Prevention (CDC) Tuberculosis Information Management System (TBIMS) from 2009 to 2015.

STUDY DESIGN

A database of child PTB for 31 provinces in mainland China over 7 years was retrospectively analysed. The spatiotemporal distribution of child PTB was described.

RESULTS

In total, 35,710 child PTB cases were notified to the TBIMS, representing only 0.60% of all 5,991,593 PTB case notifications. The average annual notified incidence of child PTB was 2.44/ per 100,000 children (95% CI: 1.77-3.10) and decreased by 52.53% in all age groups during the study period. Tibet had the highest incidence (15.95/ per 100,000 children), followed by Guizhou and Xinjiang. However, the case numbers were the most in Guizhou. The 0-1 year and 12-14 years of age groups exhibited the most cases. The positive rates of sputum smears, bacteriology and chest X-rays abnormality were 21.5%, 21.7% and 98.1%, respectively, which were lower than those 15 years of age and older (all p-values<0.0001).

CONCLUSION

The notified incidence of child PTB in mainland China decreased substantially over 7 years. Future prevention and control of PTB in children should focus on the 0-1 and 12-14 years of age groups, and Tibet and Guizhou provinces. However, the notified incidence is still low, relative to adults, suggesting substantial under-reporting. Thus, more effective care seeking, identification and registration of children with TB are crucial.

The Impact of Funding on Childhood TB Case Detection in Pakistan

This study is a review of routine programmatically collected data to describe the 5-year trend in childhood case notification in Jamshoro district, Pakistan from January 2013 to June 2018 and review of financial data for the two active case finding projects implemented during this period. The average case notification in the district was 86 per quarter before the start of active case finding project in October 2014. The average case notification rose to 322 per quarter during the implementation period (October 2014 to March 2016) and plateaued at 245 per quarter during the post-implementation period (April 2016 to June 2018). In a specialized chest center located in the district, where active case finding was re-introduced during the post implementation period (October 2016), the average case notification was 218 per quarter in the implementation period and 172 per quarter in the post implementation period. In the rest of the district, the average case notification was 160 per quarter in the implementation period and 78 during the post implementation period. The cost per additional child with TB found ranged from USD 28 to USD 42 during the interventions. A continuous stream of resources is necessary to sustain high notifications of childhood TB.

QuantiFERON-TB Performs Better in Children, Including Infants, than in Adults with Active Tuberculosis: a Multicenter Study

Immunological tests, including the QuantiFERON-TB Gold In-Tube (QFT-IT) assay, represent an important aid for diagnosing active tuberculosis (TB) and latent TB infections in children, but concerns about their use in children <5 years of age persist. This is a multicenter retrospective study comparing a population of 226 children to 521 adults with pulmonary or extrapulmonary TB. The aim was to evaluate the QFT-IT performance, analyzing both qualitative and quantitative results, according to age, birthplace, and disease localization. Compared to culture, QFT-IT sensitivity was 93.9%, 100%, and 94.4% in children ≤2, 2 to 5, and 5 to 16 years of age, respectively, and was significantly higher than that in adults (81.0%) (P < 0.0001). The rate of indeterminate test results for children (2.2%) was significantly lower than that for adults (5.2%) (P < 0.0001). In children, QFT-IT sensitivity was not affected by disease localization or birthplace (Italy born versus foreign born). Interferon gamma (IFN-γ) values in response to TB antigen and mitogen were significantly higher in children than in adults (TB antigen, median of 10 versus 1.66 IU IFN-γ/ml; mitogen, median of 10 versus 6.70 IU IFN-γ/ml; P < 0.0001). In summary, this study supports the use of QFT-IT as a complementary test for the diagnosis of pediatric TB even under 2 years of age. Our observations could be applicable to the new version of the test, QuantiFERON-TB Gold Plus, which has recently been shown to have similar sensitivity in active TB, although data in children are still lacking.

Childhood tuberculosis in Vienna between 2010 and 2016

BACKGROUND

Tuberculosis (TB) has become a rare disease in developed countries. Austria is a low incidence country for TB with an incidence rate of 7.2/100,000 in 2016. The incidence of TB has shown a constant decline in Austria from 2008 (9.8/100,000) to 2015 (6.7/100,000) but recently stagnated in 2016 (7.2/100,000). In recent years migration to Austria from countries with high TB incidence rates has increased. Therefore, this study aimed to describe the recent epidemiology of childhood TB in Vienna.

METHODS

Data of pediatric patients with active TB infections, who were hospitalized for further investigations or isolation precautions between 2010 and 2016 at the Wilhelminenspital, Austria's reference center for childhood tuberculosis, were retrospectively analyzed. Demographic and clinical data (symptoms, microbiology, radiology, immunology) were collected, compared and evaluated.

RESULTS

A total of 127 patients with active tuberculosis were included in the study. The number of admissions varied between n = 7 in 2010 and n = 26 in 2016. There were two age peaks of infected children (0-5 years: n = 41 and 15-18 years: n = 45). In 35% of the cases one parent had active TB and was suspected to be the index case. In 36% the source of infection remained unknown. Compared to young children (<5 years), adolescents (15-18 years) showed proportionally more TB-related symptoms, such as cough (41% vs. 24%), fever (15% vs. 14%) and weight loss (22% vs. 0%). At the time of admission 51% of the young children and 33% of the adolescents were free of symptoms. Intrathoracic disease was found in 80.8%, extrathoracic disease in 19.2% and 11% of the cases were tuberculous lymphadenitis. Of the patients with intrathoracic TB 54% (n = 64) had a positive microbiological result (auramine staining, bacteriological culture, PCR). In young children hilar lymphadenopathy was the most frequent radiological finding (50%), whereas in adolescents lung infiltrates were most common (36%). The sensitivity of interferon-gamma release assays (IGRA) was 0.94 compared to 0.88 of the tuberculin skin test (TST). Both test methods showed moderate concordance (ϕ-coefficient = 0.48).

CONCLUSION

A high number of asymptomatic children and adolescents with active TB were observed, which underlines the importance of efficient screening measures. Thorough history taking in all patients with TB is essential to maximize the effect of contact tracing. Overall, infection rates remained consistently low during the observation period.

Clinical Spectrum of Pediatric Tuberculosis: A Microbiological Correlation from a Tertiary Care Center

AIM AND OBJECTIVES

The paucibacillary nature of pediatric tuberculosis (TB) makes diagnosis difficult. The aim of the study was to correlate the clinical spectrum of pediatric TB with microbiological diagnosis.

MATERIALS AND METHODS

Specimens from clinically suspected pediatric TB cases were subjected to Ziehl-Neelsen staining, culture on Lowenstein-Jensen medium and cartridge-based nucleic acid amplification test (CB-NAAT) for TB.

RESULTS

Pulmonary TB was the predominant form affecting 36 of 62 (58%) patients. Tubercular meningitis was the commonest form of extrapulmonary type and affected 13 of 26 (50%) children. Microbiological diagnosis by any of the above methods could be established in 35 (56.45%) cases. While 33 of 36 (92%) patients diagnosed with pulmonary TB had radiological findings, of which only 25 (76%) could be microbiologically confirmed, only 24 of 31 (77%) patients with extrapulmonary symptoms had radiological evidence and microbiological confirmation could be achieved in 4 (17%) of these.

CONCLUSION

An integrated approach of diagnosis, including clinical-radiological, microbiological and immunological evidence should be stressed on.

Accelerating access to quality TB care for pediatric TB cases through better diagnostic strategy in four major cities of India

Background

Diagnosis of TB in children is challenging, and is largely based on positive history of contact with a TB case, clinical and radiological findings, often without microbiological confirmation. Diagnostic efforts are also undermined by challenges in specimen collection and the limited availability of high sensitivity, rapid diagnostic tests that can be applied with a quick turnaround time. The current project was undertaken in four major cities of India to address TB diagnostic challenges in pediatric population, by offering free of cost Xpert testing to pediatric presumptive TB cases, thereby paving the way for better TB care.

Methods

A high throughput lab was established in each of the four project cities, and linked to various health care providers across the city through rapid specimen transportation and electronic reporting linkages. Free Xpert testing was offered to all pediatric (0–14 years) presumptive TB cases (both pulmonary and extra-pulmonary) seeking care at public and private health facilities.

Results

The current project enrolled 42,238 pediatric presumptive TB cases from April, 2014 to June, 2016. A total of 3,340 (7.91%, CI 7.65–8.17) bacteriologically confirmed TB cases were detected, of which 295 (8.83%, CI 7.9–9.86) were rifampicin-resistant. The level of rifampicin resistance in the project cohort was high. Overall Xpert yielded a high proportion of valid results and TB detection rates were more than three-fold higher than smear microscopy. The project provided same-day testing and early availability of results led to rapid treatment initiation and success rates and very low rates of treatment failure and loss to follow-up.

Conclusion

The current project demonstrated the feasibility of rolling out rapid and upfront Xpert testing for pediatric presumptive TB cases through a single Xpert lab per city in an efficient manner. Rapid turnaround testing time facilitated prompt and appropriate treatment initiation. These results suggest that the upfront Xpert assay is a promising solution to address TB diagnosis in children. The high levels of rifampicin resistance detected in presumptive pediatric TB patients tested under the project are a major cause of concern from a public health perspective which underscores the need to further prioritize upfront Xpert access to this vulnerable population.

Quantitative Analysis of Gamma Interferon Release Assay Response in Children with Latent and Active Tuberculosis

The use of interferon gamma (IFN-γ) release assays (IGRAs) for the diagnosis of tuberculosis (TB) infection in children is still under debate because of concerns about the immature immune response in children. The aim of this study was to investigate quantitative values of the QuantiFERON-TB Gold In-Tube (QFT-IT) test, a commercially available IGRA, in a large cohort of children screened for TB infection. A retrospective analysis was conducted on samples from 517 children aged 0 to 14 years old at the Pediatric Unit of S. Orsola-Malpighi University Hospital of Bologna (Italy); quantitative responses to QFT-IT stimuli were analyzed according to diagnosis and age. Elevated IFN-γ values in the QFT-IT nil (background) tube were statistically associated with diagnosis of active TB. Quantitative IFN-γ response to Mycobacterium tuberculosis-specific antigens (TB Ag) was not significantly different in children with active TB compared to those with latent TB infection (LTBI), even though the median values were higher in the first group. When children were grouped by age, those less than 5 years old produced significantly higher levels of IFN-γ in response to TB Ag if they had active TB (median 10 IU/ml) than those with LTBI (median 1.96 IU/ml). IFN-γ response to mitogen increased with age. The overall rate of indeterminate results was low (3.9%), and no indeterminate QFT-IT values were observed in active or latent TB patients. In conclusion, quantitative QFT-IT values could provide further information to clinicians to manage TB in children, and these observations could be transferred to the new version of the test, QuantiFERON-TB Gold Plus, which to date lacks data from the pediatric population.

Recent household transmission of tuberculosis in England, 2010-2012: retrospective national cohort study combining epidemiological and molecular strain typing data

BACKGROUND

We estimate the proportion of tuberculosis (TB) in England due to recent household transmission, identify factors associated with being a household transmitter, and investigate the impact that identification of a case has on time to treatment of subsequent cases.

METHODS

TB cases notified between 2010 and 2012 in England in the same household as another case were identified; 24 locus MIRU-VNTR strain typing (ST) was used to identify household cases with likely recent transmission. Treatment delay in index and subsequent cases was compared. Risk factors for being a household transmitter were identified in univariable and multivariable analyses.

RESULTS

Overall, 7.7% (1849/24,060) of TB cases lived in a household with another case. We estimate that 3.9% were due to recent household transmission. ST data was unavailable for 67% (1242) of household pairs. For those with ST data, 64% (386) had confirmed, 11% probable (66) and 25% (155) refuted household transmission. The median treatment delay was 65 days for index cases and 37 days for subsequent asymptomatic cases. Risk factors for being a household transmitter included being under 25 years old, UK-born with Black African, Indian or Pakistani ethnicity, or born in Somalia or Romania.

CONCLUSIONS

This study has a number of implications for household TB contact tracing in low incidence countries, including the potential to reduce the diagnostic delay for subsequent household cases and the benefit of using ST to identify when to conduct source contact tracing outside the household. As 25% of TB cases in households had discordant strains, households with multiple TB cases do not necessarily represent household transmission. The additional fact that 25% of index cases within households only had extra-pulmonary TB demonstrates that, if household contact tracing is limited to pulmonary TB cases (as recently recommended in UK guidelines), additional cases of active TB in households will be missed. Our finding that no lineage of TB was associated with recent household transmission and with no increased transmissibility in the Beijing lineage compared to others, suggests that the lineage need not impact contact tracing efforts. Improvements in contact tracing have the potential to reduce transmission of TB in low incidence countries.

Prediction of Under-Detection of Paediatric Tuberculosis in the Democratic Republic of Congo: Experience of Six Years in the South-Kivu Province

INTRODUCTION

In the field of tuberculosis (TB), and particularly in regard to paediatric TB (PedTB), clinical skills of health professionals play an important role in determining quality of care. In an era where novel diagnostic technologies and efficient treatment regimens are being made available for the poorest, we must not divert our attention from the importance of clinical skills, as this deliverable remains the cornerstone of individualized patient care and ultimately the best assurance for optimal use of resources. The aim of our work was to study the epidemiology of PedTB and the determinants of PedTB under-detection in the South-Kivu Province of the Democratic Republic of Congo (DRC), a setting with nearly no technical resources allowing to support the clinical diagnosis of PedTB, i.e. chest X-rays, rapid molecular tests or culture laboratories.

METHODS

We collected TB notification data from 2010 to 2015 and analysed the space-time variations in notification for the different forms of TB among the 113 health facilities (HF) the South-Kivu Province, a region with a low HIV incidence. The different forms of TB notified were: smear positive pulmonary TB (SS+PTB), smear negative pulmonary TB (SS-PTB) and extra-pulmonary TB (EPTB). We further analysed the distribution of these different forms of the disease per age group and explored the possibility to predict the detection of PedTB.

RESULTS

Significant differences were observed between HF in regard to the proportion of paediatric TB and the proportion of SS-TB among adults. We found a strong correlation between the proportion of PedTB and three major factors: the proportion of TB cases with no bacteriological confirmation (SS-TB) among adults, the number of TB cases notified by the HF and the fact that the HF was supported or not by Médecins Sans Frontières (MSF). The proportion of SS-TB among adults was found to be a valid indicator for predicting the level of detection of PedTB at the same HF.

CONCLUSION

Our observations strongly suggest that under-detection of PedTB is associated with insufficient clinical skills and technical resources at the HF level which similarly affects other forms of the disease, in particular SS-TB. We demonstrated that, in the specific context of South-Kivu, under-detection of PedTB can be predicted by a low SS-TB/SS+PTB ratio in the adult population. In the context of severely under-resourced settings, this ratio could be used to rapidly identify HF that should benefit in priority from deeper evaluation, and eventually targeted interventions.

[A case-series analysis of tuberculosis in pediatric patients treated in a tertiary level hospital]

BACKGROUND

Tuberculosis (TB) remains a challenge because severe forms occur most frequently in children under 5 years of age and the diagnosis is complex. The objective of this paper was to describe the clinical presentation, frequency, diagnostic methods used and response to treatment in children with TB treated at a tertiary level hospital.

METHODS

The study was retrospective and descriptive of a cohort of consecutive cases treated from January 2010 to December 2013. Ninety-three medical records of children diagnosed with TB according to the definition of the NOM-006-SSA2-2013 were reviewed. Descriptive statistics were used for the analysis.

RESULTS

From 93 children, 58% were male (mean age of 7 years), 97% with a history of BCG vaccination, and 6% had contact with a TB case. The most frequent clinical forms were pulmonary (30.1%), lymph node (24.7%), miliary/disseminated (16.1%), meningeal (13%), and osteal TB (7.5%). The most common symptoms were fever and weight loss (50% and 40%, respectively). BAAR and culture were positive in 26% and 7% of all cases, respectively. The histopathological study was conclusive in 90% of the cases. The treatment was successful in 94.6%, with not associated mortality.

CONCLUSIONS

The association of clinical symptoms with alterations in chest radiography and positive PPD are useful in establishing the presumptive diagnosis and an early and appropriate treatment.

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.

Quantiferon-TB Gold In-Tube Improves Tuberculosis Diagnosis in Children

BACKGROUND

The diagnostic accuracy of Quantiferon-TB Gold In-Tube (QFT-IT) is uncertain in the pediatric population, while tuberculin skin test (TST) is still conventionally used despite its limitations. The aim of this study was to compare the performance of QFT-IT with TST in a large cohort of children screened for tuberculosis (TB) infection because of contact tracing, suspected TB, arrival from endemic country or immunosuppressive therapy.

METHODS

A retrospective analysis was conducted on 517 children 0-14 years of age evaluated at the pediatric unit of the S. Orsola-Malpighi University Hospital of Bologna, Italy; 366 of them were also tested with TST. Results were analyzed for Calmette-Guérin bacillus vaccination, country of origin, reason for testing, diagnosis and age.

RESULTS

The overall agreement between the 2 tests was 89.9%, but it was highly affected by Calmette-Guérin bacillus vaccination (P < .0001). According to diagnosis and age, QFT-IT detected latent tuberculous infection cases better than TST in all age groups. Sensitivity for diagnosing active TB in symptomatic children was higher for QFT-IT than TST (93.3% vs. 86.5%), especially in children younger than 2 years, while specificity was high for both tests (99.3% and 98.8%, respectively). Low rate of indeterminate QFT-IT results (3.9%) was not differently distributed among age groups, but was associated with diagnosis of TB exclusion (P < 0.0001), mainly pneumonia (35%), and to Italian children (P = 0.0024).

CONCLUSIONS

Despite the concern about the use of QFT-IT in children because of their immature immune system, our results suggest the preferential use of QFT-IT as a support tool for diagnosis and management of TB, even in infants.