A Prospective Cohort Study on the Prevalent and Recurrent Tuberculosis Isolates Using the MIRU-VNTR Typing

The study aims to describe the clustering characteristics of Mycobacterium tuberculosis (M.tb) strains circulating in eastern China and determine the ratio of relapse and reinfection in recurrent patients. We recruited sputum smear-positive pulmonary tuberculosis cases from five cities of Jiangsu Province, China, during August 2013 and December 2015. Patients were followed for the treatment outcomes and recurrence based on a cohort design. M.tb strains were isolated and genotyped using the 12-locus MIRU-VNTR. The Beijing family was identified by the extended Region of Difference (RD) analysis. The Hunter-Gaston Discriminatory Index (HGDI) was used to judge the resolution ability of MIRU-VNTR. The odds ratio (OR) together with 95% confidence interval (CI) were used to estimate the strength of association. We performed a cluster analysis on 2098 M.tb isolates and classified them into 545 genotypes and five categories (I, 0.19%; II, 0.43%; III, 3.34%; IV, 77.46%; V, 18.59%). After adjusting for potential confounders, the Beijing family genotype (OR = 118.63, 95% CI: 79.61–176.79, P = 0.001) was significantly related to the dominant strain infections. Patients infected with non-dominant strains had a higher risk of the pulmonary cavity (OR = 1.39, 95% CI: 1.01–1.91, P = 0.046). Among 37 paired recurrent cases, 22 (59.46%) were determined as endogenous reactivation, and 15 (40.54%) were exogenous reinfection. The type of M.tb strains prevalent in Jiangsu Province is relatively single. Beijing family strains infection is dominant in local tuberculosis cases. Endogenous reactivation appears to be a major cause of recurrent tuberculosis in Eastern China. This finding emphasizes the importance of case follow-up and monitoring after the completion of antituberculosis treatment.

Cavitary Covid Lesions - An Unusual Imaging Feature

On January 30, 2020, the coronavirus disease 2019 (Covid-19), formerly known as the 2019 novel coronavirus (2019-nCoV), was declared as a global health emergency by the World Health Organization. Coronavirus disease 2019 (Covid-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Imaging plays an essential role in the evaluation of Covid-19, with chest computed tomography (CT) being the major modality in diagnosing and managing Covid-19 pneumonia. Common signs of Covid-19 pneumonia on chest CT scan are ground-glass opacities, consolidation, nodules, and linear opacities, halo and reverse halo signs. It can be accompanied by a “crazy-paving” pattern, air bronchograms, pleural hypertrophy, and pleural effusion. Cavitations are known to occur but are rare presentations. There are cases reported in the literature of the development of pulmonary cavity after bacterial infection in the late recovery stage in SARS patients. We present a case report of this rare entity in Covid-19 infection in a previously stable patient

Disappearance of Pulmonary Cavity caused by Fungal Infection

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Tension Pneumothorax as Initial Manifestation of Granulomatosis with Polyangiitis (GPA)

Granulomatosis with polyangiitis (Wegener’s granulomatosis) is a systemic vasculitis that primarily affects small and medium vessels. Its manifestations are usually confined to the upper airway, lower airway and kidney. It can also affect other organs and systems, although this is unusual. We describe the case of a 67-year-old woman who presented with a tension pneumothorax due to rupture of a pulmonary cavity. This pulmonary cavity proved to be secondary to systemic disease which also caused a tumour in her kidney. Biopsy showed non-necrotizing granulomatosis, and even though antineutrophil cytoplasmic antibodies (ANCA) were negative, the diagnosis of granulomatosis with polyangiitis was made.

Pulmonary parenchymal involvement caused by Tropheryma whipplei

We report a 26-year-old man with left chest pain for 4 days. His chest CT showed a cavity in the left upper lung. Tuberculosis was suspected first, but metagenomics next generation sequencing (mNGS) in bronchoalveolar lavage fluid only detected Tropheryma whipplei. Tropheryma whipplei is the pathogen of Whipple’s disease. The most frequently involved organs are the eyes, heart, and central nervous system. Pulmonary parenchymal involvement is rare. To our knowledge, this is the first reported case of pulmonary cavity caused by Tropheryma whipplei. Nineteen cases of pulmonary parenchymal involvement were found by literature search. The most common respiratory symptom was cough, followed by dyspnea/breathlessness and chest pain. The most common finding in chest imaging was pulmonary nodules, followed by interstitial changes and patchy infiltration. Our case and literature review highlighted that Tropheryma whipplei infection should be considered in the differential diagnosis of pulmonary cavity, pulmonary nodules, interstitial changes, and patchy infiltration. mNGS is helpful to improve diagnosis rate.

Identifying predictors to gain sensitivity of nucleic acid amplification tests for Mycobacterium tuberculosis

Background: Tuberculosis (TB) remains one of the primary threatening of human health and its diagnosis remains unsatisfactory in clinic. Nucleic acid amplification tests (NAAT) showed higher sensitivity than culture for the diagnosis of pulmonary TB (PTB). However, NAAT are expensive and not easily deployable at the peripheral level. To improve the sensitivity of NAAT for the PTB diagnosis, the predictive factors that might be utilized to give the optimized choice of NAAT were investigated.Methods: A total of 1263 PTB suspects were enrolled for evaluation. The sensitivity, specificity and accuracy of Mtb detection in sputum and bronchoalveolar lavage fluid (BALF) were compared. Odds ratios and 95% confidence intervals were used to assess variables that associated with positive NAAT in sputum and BALF of PTB suspects.Results: An significantly enhanced sensitivity was observed when performed on NAAT (61.1%) compared with smear (9.0%) and culture of Mtb (47.8%). We found that erythrocyte sedimentation rate (ESR) (+), cavities (+) and IFN-γ release assay (IGRA) (+) are involved in the positivity of Mtb detection through NAAT. Moreover, those who are ESR (+), cavities (+) and IGRA (+), showed 86% diagnostic positivity of Mtb by NAAT.Conclusions: Our study suggested that combination of the results of ESR and IGRA and the presence of pulmonary cavity is helpful to predict the positivity of Mtb detection through NAAT. Those who are ESR (+), cavities (+) and IGRA (+), should perform NAAT for Mtb detection, because they are most likely to be bacteriologically confirmed as TB.

Severe pneumonia with formation of a pulmonary cavity associated with long-term rituximab therapy in multiple sclerosis

Nowadays B-cell depletion via anti-CD20 antibodies is commonly applied in the treatment of multiple sclerosis (MS). Yet, not much is known about infection risks associated with long-term B-cell depletion in the specific context of MS. We present the case of a 45-year-old male patient who developed severe pneumonia following 6 years of rituximab treatment for highly active relapsing-remitting MS. The patient had no additional chronic disease as well as no history of foreign travel. Although the unusual formation of a pulmonary cavity raised suspicion for tuberculosis, repeated testing via bronchoscopy and sputum remained negative. Prolonged antibiotic therapy with piperacillin/tazobactam and amoxicillin/ clavulanate led to complete recovery from symptoms. This case shows the potential risk of serious infections following continuous B-cell depletion in MS and illustrates the importance of future vigilance.