Teaching chest X-ray reading for child tuberculosis suspects

TB or not TB? Diagnostic Sensitivity, Specifity and Interobserver Agreement in the Radiological Diagnosis of Pulmonary Tuberculosis in Children

BACKGROUND

The differentiation between latent tuberculosis infection (LTBI) and tuberculosis (TB) relies on radiological changes. Confirming the diagnosis remains a challenge because typical findings are often missing in children. This study evaluates diagnostic sensitivity, specifity and interobserver agreement on the radiological diagnosis of TB by chest-x-rays in accordance to professional specialization and work experience.

METHODS

Chest x-rays of 120 children with proven tuberculosis infection were independently evaluated by general radiologists, paediatric radiologists and paediatric pulmonologists. Results were compared to a reference diagnosis created by group of experienced paediatric radiologists and paediatric pulmonologists. Primary endpoints were diagnostic sensitivity and specificity and interobserver variability defined as Krippendorfs alpha of thesel groups compared to the reference diagnosis.

RESULTS

Of the 120 chest x-rays 33 (27,5%) were diagnosed as TB by the reference standard . Paediatric pulmonologist had the highest diagnostic sensitivity (90%) but were less specific (71%) whereas general radiologist were less sensitive (68%) but more secific (95%). The best diagnostic accuracy was achieved by pediatric radiologists with a diagnostic sensitivity of 77% and specificity 95% respectively.

CONCLUSIONS

We demonstrated significant interobserver variability and relevant differences in sensitivity and specificity in the radiological diagnosis of TB between the groups. Paediatric radiologists showed the best diagnostic performance. As the diagnosis of pulmonary TB has significant therapeutic consequences for children they should be routinely involved in the diagnostic process.

Diagnostic accuracy of chest ultrasound scan in the diagnosis of childhood tuberculosis

Chest Ultrasound Scan (CUS) has been utilized in place of CXR in the diagnosis of adult pneumonia with similar or higher sensitivity and specificity to CXR. However, there is a paucity of data on the use of CUS for the diagnosis of childhood TB. This study aimed to determine the diagnostic accuracy of CUS for childhood TB. This cross-sectional study was conducted at the Mulago National Referral Hospital in Uganda. Eighty children up to 14 years of age with presumptive TB were enrolled. They all had CUS and CXR performed and interpreted independently by radiologists. The radiologist who performed the CXR was blinded to the CUS findings, and vice versa. Radiologists noted whether TB was likely or unlikely. A two-by-two table was developed to compare the absolute number of children as either TB likely or TB unlikely on CXR or CUS. This was used to calculate the sensitivity and specificity of CUS when screening for TB in children, with a correction to accommodate the use of CXR as a reference test. The sensitivity of CUS was 64% (95% CI 48.5%-77.3%), while its specificity was 42.7% (95% CI 25.5%-60.8%). Both the CUS and CXR found 29 children with a likelihood of TB, and 27 children unlikely to have TB. CUS met the sensitivity target set by the WHO TPP for Triage, and it had a sensitivity and specificity comparable to that of CXR.

Clinical Characteristics of Pulmonary Tuberculosis in Children Tested by Xpert MTB/RIF Ultra

BACKGROUND

The Xpert MTB/rifampicin Ultra (Xpert Ultra) assay improves the early diagnosis of active tuberculosis (TB) in children. Clinical evaluation is paramount for the interpretation of any positive Xpert Ultra test, especially those with low quantities of DNA.

METHODS

In this study, 391 children with suspected TB who were tested with Xpert Ultra were enrolled. The clinical characteristics and Xpert Ultra results were further analyzed.

RESULTS

The sensitivity and specificity of Xpert Ultra were 45.0% (149/331) and 96.7% (58/60), respectively. Children with higher semiquantitative scales of Xpert Ultra showed higher percentages of a positive MTB culture, positive acid-fast bacilli staining, severe type of disease, fever, cough and expectoration, a higher white blood cell count and higher C-reactive protein concentrations (all P < 0.01). Among 44 children with an Xpert Ultra trace result, there were no differences in clinical characteristics between confirmed cases and unconfirmed TB cases.

CONCLUSIONS

The prevalence of trace is relatively high and can be considered positive in paucibacillary children. Clinical presentations are associated with bacterial load quantified by Xpert Ultra. The interpretation of Xpert Ultra trace results based on clinical information is important for the diagnosis of TB.

Priority Activities in Child and Adolescent Tuberculosis to Close the Policy-Practice Gap in Low- and Middle-Income Countries

Over the past 15 years, and despite many difficulties, significant progress has been made to advance child and adolescent tuberculosis (TB) care. Despite increasing availability of safe and effective treatment and prevention options, TB remains a global health priority as a major cause of child and adolescent morbidity and mortality—over one and a half million children and adolescents develop TB each year. A history of the global public health perspective on child and adolescent TB is followed by 12 narratives detailing challenges and progress in 19 TB endemic low and middle-income countries. Overarching challenges include: under-detection and under-reporting of child and adolescent TB; poor implementation and reporting of contact investigation and TB preventive treatment services; the need for health systems strengthening to deliver effective, decentralized services; and lack of integration between TB programs and child health services. The COVID-19 pandemic has had a significant negative impact on case detection and treatment outcomes. Child and adolescent TB working groups can address country-specific challenges to close the policy–practice gaps by developing and supporting decentral ized models of care, strengthening clinical and laboratory diagnosis, including of multidrug-resistant TB, providing recommended options for treatment of disease and infection, and forging strong collaborations across relevant health sectors.

Development of a Treatment-decision Algorithm for Human Immunodeficiency Virus-uninfected Children Evaluated for Pulmonary Tuberculosis

BACKGROUND

Limitations in the sensitivity and accessibility of diagnostic tools for childhood tuberculosis contribute to the substantial gap between estimated cases and cases notified to national tuberculosis programs. Thus, tools to make accurate and rapid clinical diagnoses are necessary to initiate antituberculosis treatment in more children.

METHODS

We analyzed data from a prospective cohort of children <13 years old being routinely evaluated for pulmonary tuberculosis in Cape Town, South Africa, from March 2012 to November 2017. We developed a regression model to describe the contributions of baseline clinical evaluation to the diagnosis of tuberculosis using standardized, retrospective case definitions. We included baseline chest radiographic and Xpert MTB/RIF assay results to the model to develop an algorithm with ≥90% sensitivity in predicting tuberculosis.

RESULTS

Data from 478 children being evaluated for pulmonary tuberculosis were analyzed (median age, 16.2 months; interquartile range, 9.8-30.9 months); 242 (50.6%) were retrospectively classified with tuberculosis, bacteriologically confirmed in 104 (43.0%). The area under the receiver operating characteristic curve for the final model was 0.87. Clinical evidence identified 71.4% of all tuberculosis cases in this cohort, and inclusion of baseline chest radiographic results increased the proportion to 89.3%. The algorithm was 90.1% sensitive and 52.1% specific, and maintained a sensitivity of >90% among children <2 years old or with low weight for age.

CONCLUSIONS

Clinical evidence alone was sufficient to make most clinical antituberculosis treatment decisions. The use of evidence-based algorithms may improve decentralized, rapid treatment initiation, reducing the global burden of childhood mortality.

Tuberculosis in Pediatric Solid Organ and Hematopoietic Stem Cell Recipients

Children undergoing solid organ and hematopoietic stem cell transplantation are at high risk of morbidity and mortality from tuberculosis (TB) disease in the post-transplant period. Treatment of TB infection and disease in the post-transplant setting is complicated by immunosuppression and drug interactions. There are limited data that address the unique challenges for the management of TB in the pediatric transplant population. This review presents the current understanding of the epidemiology, clinical presentation, diagnosis, management, and prevention for pediatric transplant recipients with TB infection and disease. Further studies are needed to improve diagnosis of TB and optimize treatment outcomes for these patients.

Chest CT Scan for the Diagnosis of Pediatric Pulmonary TB: Radiological Findings and Its Diagnostic Significance

Diagnosing active TB in children remains a clinical challenge, due to difficulties in achieving a definite microbiological confirmation, aspecific clinical manifestation, low sensitivity of chest radiography (CXR). For this reason, the use of chest computed tomography (CT) scan to evaluate suspected TB pediatric cases is increasing. We retrospectively reviewed records of patients aged <16 years diagnosed with active TB at the Pediatric Infectious Disease Unit of the Catholic University of the Sacred Heart to describe CT findings and to evaluate the need for its execution for diagnosis. In 41 cases, 7 CXR were normal (17.1%) while no CT scan was evaluated as negative. In 19 cases (46.3%), CXR was considered non-probable TB pulmonary, compared with 11 of 37 cases (29.7%) of CT. In 15 cases (36.6%) CXR was described as probable for TB pulmonary, instead 26 of the 37 cases evaluated by CT (70.3%) were classified as probable TB. We describe CT findings in patients with pediatric TB. We confirmed that CT can improve the diagnostic accuracy. In particular, the comparison between the CT and CXR ability in detecting cases of pulmonary TB in accordance with the proposed radiological probability criteria, showed a superiority of CT in detecting probable TB pictures (70.3%) compared with 36.6% of the x-Ray.

Interpretation of pediatric chest radiographs by non-radiologist clinicians in Botswana using World Health Organization criteria for endpoint pneumonia

BACKGROUND

In low- and middle-income countries, chest radiographs are most frequently interpreted by non-radiologist clinicians.

OBJECTIVE

We examined the reliability of chest radiograph interpretations performed by non-radiologist clinicians in Botswana and conducted an educational intervention aimed at improving chest radiograph interpretation accuracy among non-radiologist clinicians.

MATERIALS AND METHODS

We recruited non-radiologist clinicians at a referral hospital in Gaborone, Botswana, to interpret de-identified chest radiographs for children with clinical pneumonia. We compared their interpretations with those of two board-certified pediatric radiologists in the United States. We evaluated associations between level of medical training and the accuracy of chest radiograph findings between groups, using logistic regression and kappa statistics. We then developed an in-person training intervention led by a pediatric radiologist. We asked participants to interpret 20 radiographs before and immediately after the intervention, and we compared their responses to those of the facilitating radiologist. For both objectives, our primary outcome was the identification of primary endpoint pneumonia, defined by the World Health Organization as presence of endpoint consolidation or endpoint effusion.

RESULTS

Twenty-two clinicians interpreted chest radiographs in the primary objective; there were no significant associations between level of training and correct identification of endpoint pneumonia; concordance between respondents and radiologists was moderate (κ=0.43). After the training intervention, participants improved agreement with the facilitating radiologist for endpoint pneumonia from fair to moderate (κ=0.34 to κ=0.49).

CONCLUSION

Non-radiologist clinicians in Botswana do not consistently identify key chest radiographic findings of pneumonia. A targeted training intervention might improve non-radiologist clinicians' ability to interpret chest radiographs.

Comparative effectiveness of a mnemonic-use approach vs. self-study to interpret a lateral chest X-ray

The chest X-ray is the most commonly performed medical imaging study; however, the lateral chest film intimidates many physicians and medical students. The lateral view is more difficult to interpret than the frontal view but provides important information that is either not visible or not as evident on frontal view, and inability to read it may lead to missed diagnoses and more expensive imaging. The objective of this study was to assess a novel mnemonic-based approach to teaching medical students to proficiently read a lateral film using a prospective pilot study. A clinical faculty radiologist taught two groups of second-year medical students to read a lateral chest X-ray. One group learned a novel mnemonic-based method (MUM), and the other cohort performed directed web-based self-study (STMM). Each cohort was given a pre- and postassessment, and their performance was analyzed. A total of n = 29 students participated with n = 14 being taught the mnemonic method. The MUM group significantly (P = 0.001) improved their score vs. the STMM group This study demonstrates students can quickly and effectively learn to read a lateral chest film using this novel mnemonic.

Evaluation of a chest radiograph reading and recording system for tuberculosis in a HIV-positive cohort

AIM

To assess the impact of introducing a chest radiograph reading and recording system (CRRS) with a short training session, on the accuracy and inter-reader variability of tuberculosis (TB) interpretation of chest radiographs (CXRs) by a group of non-expert readers in a human immunodeficiency virus (HIV)-positive cohort.

MATERIALS AND METHODS

A set of 139 CXRs was reviewed by a group of eight physicians pre- and post-intervention at two clinics in Shan State, Myanmar, providing HIV/TB diagnosis and treatment services. The results were compared against the consensus of expert radiologists for accuracy.

RESULTS

Overall accuracy was similar pre- and post-intervention for most physicians with an average area under the receiver operating characteristic curve difference of 0.02 (95% confidence interval: -0.03, 0.07). The overall agreement among physicians was poor pre- and post-intervention (Fleiss κ=0.35 and κ=0.29 respectively). The assessment of agreement for specific disease patterns associated with active TB in HIV-infected patients showed that for intrinsically subtle findings, the agreement was generally poor but better for the more intrinsically obvious disease patterns: pleural effusion (Cohen's kappa range = 0.37-0.67) and milliary nodular pattern (Cohen's kappa range = 0.25-0.52).

CONCLUSION

This study demonstrated limited impact of the introduction of a CRRS on CXR accuracy and agreement amongst non-expert readers. The role in which CXRs are used for TB diagnosis in a HIV-positive cohort in similar clinical contexts should be reviewed.

Digital platform for improving non-radiologists' and radiologists' interpretation of chest radiographs for suspected tuberculosis - a method for supporting task-shifting in developing countries

BACKGROUND

Shifting X-ray interpretation to non-radiologists can help to address radiologist shortages in developing countries.

OBJECTIVE

To determine the change in accuracy of non-radiologists and radiologists for the radiographic diagnosis of paediatric tuberculosis after a short skill-development course.

MATERIALS AND METHODS

Participants interpreted 15 paediatric chest radiographs before and after a 30-minute course using three possible responses: (1) diagnostic for tuberculosis, (2) abnormal but inconclusive for diagnosis of tuberculosis and (3) normal. We compared proportions of correct diagnoses, sensitivity, and specificity, before and after the course.

RESULTS

We included 256 participants comprising 229 non-radiologists (134 radiographers, 32 paediatricians, 39 Médecins Sans Frontières clinicians and 24 physicians including paediatricians) and 27 radiologists. Mean change proportions of correct diagnosis ranged from -27% to 53% for individuals and 9% to 20% for groups. All groups showed a statistically significant improvement. Mean change in diagnostic sensitivity ranged from -38% to 100% for individuals and from 16% to 41% for groups. All groups showed a statistically significant improvement. Mean change in specificity ranged from -57% to 57% for individuals and from -15% to -4% for groups. The decrease was statistically significant for physicians, paediatricians and radiographers.

CONCLUSION

The course resulted in increased correct diagnoses and improved sensitivity at the expense of specificity.

Ending neglect: providing effective childhood tuberculosis training for health care workers in Tanzania

SETTING

Health care facilities in Dar es Salaam, Pwani, and Arusha, Tanzania.

OBJECTIVE

To assess health care worker (HCW) knowledge and practices 1 year after specialized training in childhood tuberculosis (TB).

DESIGN

Using a standardized survey, we interviewed a convenience sample of HCWs providing both general and specialized care to children.

RESULTS

We interviewed 117 HCWs in TB clinics, maternal and child health clinics, human immunodeficiency virus (HIV) clinics, out-patient departments, and pediatric in-patient wards at 12 facilities. A total of 81 HCWs (62% of nurses, 74% of clinicians) reported having attended the national childhood TB training course. Most HCWs responded correctly to questions on childhood TB diagnosis, treatment, and TB-HIV co-management, regardless of training history. Most HCWs reported that they routinely obtain chest radiographs, HIV testing, and a TB contact history when evaluating children for TB. Less than half of HCWs reported routinely obtaining sputum for mycobacterial culture or performing a tuberculin skin test. Three times as many trained as untrained HCWs reported having ever prescribed isoniazid preventive therapy (IPT) to a child (P < 0.05).

CONCLUSION

In general, levels of childhood TB knowledge were high and practices were in accordance with national guidance. Specific gaps in diagnosis, treatment and use of IPT were identified for future focused training.

New Diagnostics for Childhood Tuberculosis

The challenge of diagnosing childhood tuberculosis (TB) results from its paucibacillary nature and the difficulties of sputum collection in children. Mycobacterial culture, the diagnostic gold standard, provides microbiological confirmation in only 30% to 40% of childhood pulmonary TB cases and takes up to 6 weeks to result. Conventional drug susceptibility testing requires an additional 2 to 4 weeks after culture confirmation. In response to the low sensitivity and long wait time of the traditional diagnostic approach, many new assays have been developed. These new tools have shortened time to result; however, none of them offer greater sensitivity than culture.