Use of Xpert Contributes to Accurate Diagnosis, Timely Initiation, and Rational Use of Anti-TB Treatment Among Childhood Tuberculosis Cases in South Central Ethiopia

Patterns of childhood tuberculosis diagnosis in Ethiopia: A multicenter cross-sectional study

Background

Children share 12% of the global 10 million people infected with tuberculosis (TB) each year. Closing case detection gap in children remains difficult, with 56% of all children and 65% under-five with TB missed each year. We aimed to assess the patterns of childhood TB diagnosis and underlying determinants in Ethiopia when different TB diagnostic platforms are applied.

Methods

A multi-site, cross-sectional study was carried out in Ethiopia as part of the larger EXIT-TB study - evidence-based multiple focused integrated intensified TB screening package. Outpatient children aged ≤ 15 with cough of any duration seeking care at four healthcare facilities in Ethiopia were enrolled consecutively. Participants underwent sputum Xpert MTB/RIF and/or smear microscopy and posteroanterior chest X-ray (CXR), and their clinical and sociodemographic data were captured using a structured questionnaire. Data were analyzed using Stata version 23. Multiple regression model was computed to determine the factors that influence TB case detection, with a 95% confidence interval (CI) and p < 0.05 taken as statistically significant.

Results

A total of 438 children were enrolled. Of these, 399 had CXR examination of which 55 (13.8%) were suggestive of TB, 270 had Xpert MTB/RIF testing of which 32 (11.9%) were positive, and AFB smear microscopy was done for 51 children of which 2 (3.9%) were positive. Febrile children were more likely to be diagnosed with pulmonary TB than those without fever [aPR = 1.3, 95% CI (1.1-1.4)], and those with a TB contact history were more likely to be diagnosed with pulmonary TB than those with no such contacts [aPR = 1.2, 95% CI (1.1-1.3)]. Children from rural residences were more likely to be diagnosed with TB than those from urban residences [aPR = 1.3, 95% CI (1.1-1.5)].

Conclusion

The findings showed that clinical diagnosis remains an important method of TB diagnosis in children and the preferred choice to avert underdiagnosis. A more sensitive TB diagnostic method for children was symptom screening, followed by CXR and Xpert MTB/RIF assay or smear microscopy. Hence, an algorithm that combines clinical, CXR, and microbiological confirmatory tests can improve the rate of pulmonary TB diagnosis in children till more accurate and cost-effective diagnostic tools are accessible. Fever, weight loss, and TB contact history are highly associated with TB positivity rates in children.

Impact of Xpert MTB/RIF in the Diagnosis of Childhood Tuberculosis in Rural Ethiopia

BACKGROUND

This study assesses the impact of the Xpert MTB/RIF in the diagnosis of childhood tuberculosis (TB) in a rural hospital in a resource-constrained setting.

METHODS

Retrospective cross-sectional study in children evaluated for presumptive TB from 1 June 2016 to 31 May 2017 at the Gambo General Hospital in rural Southern Ethiopia. Children were evaluated according to a defined protocol based on national guidelines. Samples were submitted for Xpert MTB/RIF assay to the nearest reference laboratory.

RESULTS

Of the 201 children assessed for presumptive TB, 46.3% (93/201) were diagnosed with TB. Of these, 49.5% (46/93) were microbiologically confirmed, mostly by Xpert MTB/RIF (only one patient was diagnosed by smear alone). The rest were clinically diagnosed. Microbiologically confirmed patients had a higher mean age, longer duration of fever and cough and lymphadenopathy more frequently than those clinically diagnosed. Gastric aspirates were Xpert MTB/RIF-positive in 18.2% of the samples (26/143); none were smear-positive (0/140). Sputum samples were Xpert MTB/RIF-positive in 27.1% (13/35) of the samples and smear-positive in 8.6% (3/35). There were no HIV-positive patients and just one case of rifampicin-resistant TB. A long delay (median 15 days) was detected in returning the results.

CONCLUSION

Xpert MTB/RIF serves as an important adjunctive test for diagnosing childhood TB in rural settings, with microbiological confirmation in up to half the TB cases. Processes need to be optimized to achieve an early diagnosis. The diagnosis of childhood TB in high-burden countries such as Ethiopia still relies largely upon diagnostic algorithms and the clinician's skills.Lay summaryWorld Health Organization recommends the use of Xpert MTB/RIF to improve the microbiological diagnosis of childhood tuberculosis (TB) since 2014, but the impact of this test under real conditions in rural areas of low-income countries is not clear. We conducted a cross-sectional study in children evaluated for presumptive TB from 1 June 2016 to 31 May 2017 at the Gambo General Hospital in rural Southern Ethiopia. Children were evaluated according to a clinical protocol based on national guidelines and samples were submitted for Xpert MTB/RIF assay to the nearest reference laboratory.Of the 201 children assessed, 46.3% (93/201) were diagnosed with tuberculosis. Of these, 48.4% (45/93) were microbiologically confirmed by Xpert MTB/RIF [smear microscopy only diagnosed the 5.4% (5/93)]. Patients with microbiologically confirmed tuberculosis had a higher mean age, longer duration of fever and cough and had lymphadenopathy more frequently than those clinically diagnosed. A long delay in returning the results (median 15 days) was detected. Xpert MTB/RIF serves as an important test for diagnosing childhood TB in rural settings, with microbiological confirmation in up to half the cases. Processes need to be optimized to achieve an early diagnosis. The diagnosis of childhood TB in high-burden countries still relies largely upon diagnostic algorithms and the clinician's skills.

Diagnostic Advances in Childhood Tuberculosis—Improving Specimen Collection and Yield of Microbiological Diagnosis for Intrathoracic Tuberculosis

There is no microbiological gold standard for childhood tuberculosis (TB) diagnosis. The paucibacillary nature of the disease, challenges in sample collection in young children, and the limitations of currently available microbiological tests restrict microbiological confirmation of intrathoracic TB to the minority of children. Recent WHO guidelines recommend the use of novel rapid molecular assays as initial diagnostic tests for TB and endorse alternative sample collection methods for children. However, the uptake of these tools in high-endemic settings remains low. In this review, we appraise historic and new microbiological tests and sample collection techniques that can be used for the diagnosis of intrathoracic TB in children. We explore challenges and possible ways to improve diagnostic yield despite limitations, and identify research gaps to address in order to improve the microbiological diagnosis of intrathoracic TB in children.

Diagnostic value of microRNA-155 in active tuberculosis: A systematic review and meta-analysis

BACKGROUND

Tuberculosis (TB) is a preventable and treatable disease, but the increased mortality and morbidity associated with TB continues to be a leading cause of death globally. MicroRNA (miRNA)-155 has been recognized as a marker of many lung diseases. However, the effectiveness of this marker for diagnosing TB remains unclear.

METHODS

A detailed search (updated on February 6, 2021) of literature published in the Wanfang database, EMBASE, PubMed, CNKI, and Cochrane Library was conducted to identify eligible studies suitable for inclusion in the current research. The positive likelihood ratio, negative likelihood ratio, specificity, area under the curve, sensitivity, and diagnostic odds ratio were used to investigate the diagnostic potential of miRNA-155.

RESULTS

A total of 122 studies related to active TB, which completely complied with the inclusion and exclusion criteria of our meta-analysis, were included. The overall results suggested a moderately high diagnostic accuracy and efficacy of miRNA-155, with a specificity of 0.85 (95% confidence interval = 0.77-0.91) and sensitivity of 0.87 (95% confidence interval = 0.76-0.93). The result based on dysregulated status demonstrated that the upregulated group yielded better accuracy and efficacy than the downregulated group. Notably, the accuracy and efficacy of miRNA-155 in pediatric TB were higher than those in adult TB. The results showed that the accuracy and efficacy of miRNA-155 in children were higher than those in adults.

CONCLUSION

The results of the meta-analysis suggested that miRNA-155 could serve as an effective biomarker for identifying active TB.