Diagnosis of pediatric pulmonary tuberculosis with special reference to polymerase chain reaction based nucleic acid amplification test

Innovations in Molecular Identification of Mycobacterium tuberculosis

Tuberculosis (TB) continues to be a significant public health concern on a global scale. Quick and precise identification of Mycobacterium tuberculosis (MTB) in symptomatic patients is pivotal for worldwide TB eradication initiatives. As an infectious disorder induced by MTB, it remains a critical threat to public health, particularly in poor countries, due to an inadequate diagnostic research laboratory. There is a need for a persistent incentive to reduce response time for effective diagnosis and control of TB infection, which is a benefit that molecular techniques provide over traditional methods. Although there is a tremendous overall prevalence of TB and a relatively poor probability of case identification worldwide. Common screening techniques have focused on tests that have many fundamental shortcomings. Due to the development of antibiotic-resistant Mycobacterium strains, TB is one of the leading contributors to fatalities. It is now possible to examine TB using molecular detection techniques, which are faster and more cost-effective than previous methods, such as standard culture procedures to test and verify antibiotic resistance in patients with TB. Whole genome sequencing (WGS), faster nucleic acid amplification tests, has made it easier to diagnose and treat TB more quickly. This article addresses the genetic approaches for detecting Mycobacterium tuberculosis complex (MTBC) in clinical specimens as well as antibiotic resistance in mycobacterium and discusses the practical limitations of using these methods.

Paediatric tuberculosis diagnosis using Mycobacterium tuberculosis real-time polymerase chain reaction assay: a systematic review and meta-analysis

BACKGROUND

Rapid and accurate diagnosis of paediatric tuberculosis (TB) is key to manage the disease and to control and prevent its transmission. Collection of quality sputum samples without invasion methods from paediatrics (age < 16 years) with presumptive pulmonary tuberculosis (PTB) remains a challenge. Thus, the aim of this meta-analysis was to assess the overall accuracy of a real-time polymerase chain reaction (RT-PCR)-based assay, for routine diagnosis of MTB in different samples from paediatrics with active pulmonary and extra-pulmonary tuberculosis using mycobacterial culture as the gold standard in clinical microbiology laboratories.

METHODS

We conducted a systematic review and meta-analysis to examine the diagnostic test accuracy of RT-PCR based assay for the detection of MTB in paediatric clinical samples. A systematic literature search was performed for publications in any language. MEDLINE via PubMed, EMBASE, and Web of Science were among 9 bibliographic databases searched from August 2019 until November 2020. Bivariate random-effects model of meta-analysis were performed to generate pooled summary estimates (95% CIs) for overall accuracy of RT-PCR based assay compared to mycobacterial culture as the reference standard.

RESULTS

Of the 1592 candidate studies, twenty-one eligible studies met our inclusion criteria. In total, the review and meta-analysis included 5536 (3209 PTB and 2327 EPTB). Summary estimates for pulmonary TB (11 studies) were as follows: sensitivity 56 (95% CI 51-62), specificity 97 (95% CI 96-98) and summary estimates for extra-pulmonary TB (10 studies) were as follows: sensitivity 87 (95% CI 82-91)) specificity 100 (95% CI 99-100). There was significant heterogeneity in sensitivity and specificity among the enrolled studies (p < 0.001).

CONCLUSIONS

Our results suggested that the RT-PCR based assay could be a useful test for the diagnosis of paediatrics TB with high sensitivity and specificity in low-income/high-burden and upper medium income/low-burden settings. From the study, RT-PCR assay demonstrated a high degree of sensitivity for extra-pulmonary TB and good sensitivity for pulmonary TB which is an important factor in achieving effective global control and for patient management in terms of initiating early and appropriate anti-tubercular therapy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018104052.

Comparing Treatment Outcomes between Confirmed and Non-Confirmed Childhood TB Cases: Study from a Major Tertiary Center in Thailand

BACKGROUND

Tuberculosis (TB) in children is challenging to diagnose due to its non-specific symptoms and difficulties in obtaining confirmatory laboratory results. This study aimed to compare the treatment outcomes of confirmed and non-confirmed TB in children.

METHODS

The medical records of children aged ≤ 15 years diagnosed with TB at Songklanagarind Hospital from January 2007 to December 2018 were examined. The TB cases were classified into three groups, confirmed cases (positive culture and/or polymerase chain reaction), probable cases (positive histopathological and/or acid-fast bacilli results) and presumptive cases (clinical manifestations and imaging findings compatible with TB and good response to anti-TB drugs but without microbiological confirmation).

RESULTS

Of 177 children, 66 (37.3%) had a confirmed diagnosis, 57 (32.2%) a probable diagnosis, and 54 (30.5%) a presumptive diagnosis. The successful treatment rates of the confirmed, probable and presumptive TB groups were 80.3%, 87.7% and 92.6%, respectively (p = 0.21). Of the 54 presumptive cases, a history of household contact with TB led to a diagnosis of asymptomatic pulmonary TB in 10 (18.5%) cases. Patients with a presumptive diagnosis were less likely to have disseminated and/or miliary TB (1.9% vs. 7.0% of probable vs. 22.7% of confirmed, p < 0.01).

CONCLUSIONS

Only one-third of the study patients had a confirmed TB diagnosis. The successful treatment and mortality rates did not significantly differ among the three groups. To increase the detection rate of early diagnosis of childhood TB, physicians should perform active TB contact investigations in household members of the index case.

Pulmonary tuberculosis in a Pediatric Reference Hospital in Bogotá, Colombia

BACKGROUND

In Colombia, epidemiological and clinical information related to pediatric tuberculosis (TB) is scarce. Data are needed to define the impact of the disease and to strengthen measures for detection and treatment. It is proposed to analyze the pediatric population diagnosed with pulmonary TB in a national reference institution.

METHODS

Retrospective observational study including pediatric patients with pulmonary and miliary TB, and pulmonary and extrapulmonary involvement, treated between January 1, 2008 and December 31, 2016. A descriptive analysis of the selected variables was done.

RESULTS

A total of 93 cases of diagnosed TB were identified, of which 61 cases were classified as pulmonary (65.6%). The location of TB occurred only in lungs in 51 patients (83.6%), was miliar in 3 (4.9%), pulmonary and extrapulmonary involvement in 7 patients (11.5%). The mean age was 7.5 years (0.5-18 years). Clinical criteria used for diagnosis was related to 98.3% of the cases, whereas radiological criteria in 90.2%. Bacteriological criterion was met in 42.6% of the cases. The most frequent symptoms were coughing (83.6%), fever (63.9%), and weight loss (26.2%); human immunodeficiency virus co-infection occurred in 3 cases (4.9%). During treatment, 5 mortality cases were recorded, although they were not attributable to TB.

CONCLUSIONS

The epidemiological characterization of pediatric patients with pulmonary TB helps to achieve a better diagnostic approach in this population. Improving monitoring and follow-up activities in children with pulmonary TB, as well as promoting actions for adequate prevention and treatment is highly necessary.

Molecular Diagnosis of Tuberculosis

Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by Mycobacterium tuberculosis (MTB), TB remains a major public health issue especially in developing nations due to the lack of adequate diagnostic testing facilities. Diagnosis of TB has entered an era of molecular detection that provides faster and more cost-effective methods to diagnose and confirm drug resistance in TB cases, meanwhile, diagnosis by conventional culture systems requires several weeks. New advances in the molecular detection of TB, including the faster and simpler nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have resulted in a shorter time for diagnosis and, therefore, faster TB treatments. In this review, we explored the current findings on molecular diagnosis of TB and drug-resistant TB to see how this advancement could be integrated into public health systems in order to control TB.

Childhood Tuberculosis in a Sub-Saharan Tertiary Facility: Epidemiology and Factors Associated with Treatment Outcome

Childhood tuberculosis (TB) is a diagnostic challenge in developing countries, and patient outcome can be influenced by certain factors. We report the disease course, clinical profile and factors associated with treatment outcome in a tertiary facility of Kinshasa. Documentary and analytical studies were conducted using clinical and exploratory data for children aged up to 15 years who were admitted to the University Clinics of Kinshasa for TB. Data are presented as frequencies and averages, and binary and logistic regression analyses were performed. Of 283 children with TB, 82 (29.0%) had smear-negative TB, 40 (14.1%) had smear-positive TB, 159 (56.1%) had extra-pulmonary TB (EPTB), 2 (0.7%) had multidrug-resistant TB (MDR-TB), 167 (59.0%) completed treatment, 30 (10.6%) were cured, 7 (2.5%) failed treatment, 4 (1.4%) died, 55 (19.4%) were transferred to health centers nearest their home, and 20 (7.0%) were defaulters. In the binary analysis, reported TB contacts (p = 0.048), type of TB (p = 0.000), HIV status (p = 0.050), Ziehl-Nielsen test result (p = 0.000), Lowenstein culture (p = 0.004) and chest X-ray (p = 0.057) were associated with outcome. In the logistic regression, none of these factors was a significant predictor of outcome. Tertiary level care facilities must improve the diagnosis and care of patients with childhood TB, which justifies the development of alternative diagnostic techniques and the assessment of other factors that potentially affect outcome.