Unilateral lower lung field opacities on chest radiography: a comparison of the clinical manifestations of tuberculosis and pneumonia

Microbiological aspects and clinical impact of lower lung field tuberculosis: An observational cohort study in Peru

OBJECTIVES

Approximately 40% of tuberculosis (TB) cases remain undiagnosed globally. Lower lung field TB (LLF TB) presents atypically and is often misidentified as other lung diseases, leading to diagnostic delays in resource-limited settings. It may contribute to increased TB transmission and mortality. We aimed to identify microbiological determinants of LLF TB and evaluate treatment responses to optimize care.

METHODS

We conducted an observational cohort study in Lima, Peru, enrolling adults with microbiologically confirmed pulmonary TB (PTB) diagnosed by GeneXpert MTB/RIF assay or sputum culture. Mycobacterium tuberculosis (MTB) lineage was determined using whole-genome sequencing. Due to the delayed chest radiograph changes in LLF TB compared to non-LLF TB, we measured changes in the St. George's Respiratory Questionnaire (SGRQ) score at 2-month treatment mark and evaluated World Health Organization-specified final treatment outcomes. We used logistic regression to evaluate the associations between LLF TB and microbiological determinants and treatment outcomes. We used linear regression to assess whether the change in SGRQ scores over the first 2 months of treatment varied by LLF TB status.

RESULTS

Among 1316 PTB patients, 84 (6%) had LLF TB. Compared to non-LLF TB patients, LLF TB patients were more likely to be smear-negative (adjusted odds ratio [aOR] [95% CI] = 2.04 [1.28-3.23], P = 0.002) and to be infected with Lineage 2 (aOR [95% CI] = 1.95 [95% CI: 1.07-3.41; P = 0.024]). People with LLF TB had less improvement in SGRQ scores after 2 months of treatment (adjusted score difference [95% CI] = -6.29 [-10.99 to -1.59], P = 0.009), while they experienced better final outcomes compared to non-LLF TB patients, though this difference did not reach statistical significance (aOR = 0.43 [95% CI: 0.13-1.05], P = 0.103).

CONCLUSION

Patients with LLF TB are more likely than those with upper lung lesions to be sputum-negative on conventional tests, to be infected with Lineage 2, and to show less clinical improvement after treatment.

Development and validation of a 3D-convolutional neural network model based on chest CT for differentiating active pulmonary tuberculosis from community-acquired pneumonia

PURPOSE

To develop and validate a 3D-convolutional neural network (3D-CNN) model based on chest CT for differentiating active pulmonary tuberculosis (APTB) from community-acquired pneumonia (CAP).

MATERIALS AND METHODS

Chest CT images of APTB and CAP patients diagnosed in two imaging centers (n = 432 in center A and n = 61 in center B) were collected retrospectively. The data in center A were divided into training, validation and internal test sets, and the data in center B were used as an external test set. A 3D-CNN was built using Keras deep learning framework. After the training, the 3D-CNN selected the model with the highest accuracy in the validation set as the optimal model, which was applied to the two test sets in centers A and B. In addition, the two test sets were independently diagnosed by two radiologists. The 3D-CNN optimal model was compared with the discrimination, calibration and net benefit of the two radiologists in differentiating APTB from CAP using chest CT images.

RESULTS

The accuracy of the 3D-CNN optimal model was 0.989 and 0.934 with the internal and external test set, respectively. The area-under-the-curve values with the 3D-CNN model in the two test sets were statistically higher than that of the two radiologists (all P < 0.05), and there was a high calibration degree. The decision curve analysis showed that the 3D-CNN optimal model had significantly higher net benefit for patients than the two radiologists.

CONCLUSIONS

3D-CNN has high classification performance in differentiating APTB from CAP using chest CT images. The application of 3D-CNN provides a new automatic and rapid diagnosis method for identifying patients with APTB from CAP using chest CT images.

A Vietnamese woman with a 2-week history of cough

A 52-year-old nonsmoker Vietnamese woman without any past medical history presented at the emergency department in May 2018 for a 2-week history of cough.

Can you diagnose this case of a Vietnamese woman with a 2-week history of cough? 
http://ow.ly/9cIG30n21Pu

Tuberculosis-associated Immune Thrombocytopenia: A Case Report

Various hematological manifestations are known to occur with tuberculosis (TB), but its association with immune thrombocytopenia is uncommon and not well recognized. Here, the case of a 39-year-old male who presented with a history of epistaxis and hematuria is described. The patient was found to have diffuse lymphadenopathy both clinically and radiologically. He was diagnosed with immune thrombocytopenia; however, there was a delay in the diagnosis of TB because of the patient's refusal of lymph node biopsy and late recognition of the association between TB and immune thrombocytopenia. Treatment with steroids without antituberculosis medications may have led to reactivation and dissemination of tuberculous infection in this patient. Later, the patient was readmitted with a suspected community-acquired pneumonia and the sputum smear was positive for acid-fast bacilli. Unfortunately, the patient died after he developed sepsis and multiorgan failure. The purpose of this case report is to highlight this rare combination and create awareness among clinicians to consider TB as an underlying etiology of immune thrombocytopenia, especially if there are other associated physical findings such as the presence of lymphadenopathy.

Study of 9 Cases of Tuberculosis Pneumonia in Children at Chu of Brazzaville, Congo

In the Republic of Congo, a country where tuberculosis is endemic, there have not been many reports about tuberculosis pneumonia. This study aimed to describe the epidemiology, clinical features, and outcome of tuberculosis pneumonia in children. This was a retrospective study of 9 cases of children admitted from 2002 to 2015, that is, 0.7 cases per year. The average age was 37 months. The mean delay from the beginning of symptoms to the visit to a medical center was 36 days (range = 4-93 days). Physical examination indicated a pulmonary consolidation in 6 cases. Chest X-ray revealed a unilateral opacity in all cases. Sputum and gastric washing bacilloscopies were positive in all cases, and HIV serology was positive in 2 cases. Therapeutic observance was perfect and the evolution favorable. Tuberculosis pneumonia must be systematically proposed for children under 5 years of age, who present symptoms that are in contrast with the seriousness of chest X-ray injuries.

Does empirical treatment of community-acquired pneumonia with fluoroquinolones delay tuberculosis treatment and result in fluoroquinolone resistance in Mycobacterium tuberculosis? Controversies and solutions

The role of fluoroquinolones (FQs) as empirical therapy for community-acquired pneumonia (CAP) remains controversial in countries with high tuberculosis (TB) endemicity owing to the possibility of delayed TB diagnosis and treatment and the emergence of FQ resistance in Mycobacterium tuberculosis. Although the rates of macrolide-resistant Streptococcus pneumoniae and amoxicillin/clavulanic acid-resistant Haemophilus influenzae have risen to alarming levels, the rates of respiratory FQ (RFQ) resistance amongst these isolates remain relatively low. It is reported that ca. 1–7% of CAP cases are re-diagnosed as pulmonary TB in Asian countries. A longer duration (≥7 days) of symptoms, a history of night sweats, lack of fever (>38 °C), infection involving the upper lobe, presence of cavitary infiltrates, opacity in the lower lung without the presence of air, low total white blood cell count and the presence of lymphopenia are predictive of pulmonary TB. Amongst patients with CAP who reside in TB-endemic countries who are suspected of having TB, imaging studies as well as aggressive microbiological investigations need to be performed early on. Previous exposure to a FQ for >10 days in patients with TB is associated with the emergence of FQ-resistant M. tuberculosis isolates. However, rates of M. tuberculosis isolates with FQ resistance are significantly higher amongst multidrug-resistant M. tuberculosis isolates than amongst susceptible isolates. Consequently, in Taiwan and also in other countries with TB endemicity, a short-course (5-day) regimen of a RFQ is still recommended for empirical therapy for CAP patients if the patient is at low risk for TB.