Positive Acid-fast Bacilli Smear Research Articles

Beyond Symptoms: Radiologic identification of asymptomatic Mycobacterium avium complex pulmonary infections

BackgroundAlthough international nontuberculous mycobacterial pulmonary disease (NTM-PD) guidelines highlight symptom presence at diagnosis, the clinical characteristics of asymptomatic Mycobacterium avium complex pulmonary infection (MAC-PI) patients remain understudied. We clarified the clinical characteristics and course of asymptomatic MAC-PI patients. MethodsWe retrospectively analyzed 200 consecutive patients with MAC-PIs and adequate available data who newly met the microbiological and radiological criteria for NTM-PD at Fukujuji Hospital from January 2018 to June 2020. We compared the clinical characteristics and course of asymptomatic patients with symptomatic patients and evaluated factors influencing treatment initiation through multivariate analysis. Results111 patients were symptomatic and 89 were asymptomatic at diagnosis. While the proportion was significantly lower than that in the symptomatic group (28.8 %), 15.7 % of asymptomatic group patients had cavitary lesions (P = 0.042). In the asymptomatic group, treatments were initiated in 38 (42.7 %) patients, and cavitary lesions, a positive acid-fast bacilli smear, and younger age were independent risk factors for treatment initiation. Among 22 (57.9 %) patients who experienced disease progression necessitating treatment during follow-up, 13 (34.2 %) displayed radiological progression without any worsening of symptoms. Agents used for treatment were consistent across the groups, with no significant differences in culture conversion, microbiological recurrence rates, or spontaneous culture conversion rates. ConclusionRoutine health checkups and radiological examinations can detect clinically important MAC-PIs even in the absence of symptoms. Considering that the clinical course of asymptomatic MAC-PI patients is largely similar to that of symptomatic patients, timely and appropriate management and intervention are essential for all MAC-PI patients.

Association of indicators of extensive disease and rifampin-resistant tuberculosis treatment outcomes: an individual participant data meta-analysis

BackgroundIndicators of extensive disease—acid fast bacilli (AFB) smear positivity and lung cavitation—have been inconsistently associated with clinical rifampin-resistant/multidrug-resistant tuberculosis (RR/MDR-TB) outcomes. We evaluated the association of these indicators with end-of-treatment...

The Clinical Implications of Serum Carbohydrate Antigen 19-9 Levels in Patients with Nontuberculous Mycobacteria Pulmonary Disease.

Serum carbohydrate antigen 19-9 (CA19-9) levels can increase in nontuberculous mycobacteria pulmonary disease (NTM-PD), and the levels correlate with disease activity. We compared the clinical characteristics of NTM-PD patients with and without elevated CA19-9 levels and evaluated its association with antibiotic response in a retrospective study of NTM-PD patients diagnosed between January 1994 and December 2020. We analyzed 1112 patients who had serum CA19-9 measured: 322 with elevated CA19-9 and 790 with normal CA19-9. The erythrocyte sedimentation rate and C-reactive protein levels were significantly higher in the elevated CA19-9 group (p < 0.001 and p = 0.029, respectively). The 1-year culture conversion rate after antibiotics did not differ between the elevated (n = 206) and normal (n = 377) CA19-9 groups (80% vs. 72%, p = 0.055). Analysis of a subset of 434 patients revealed that current smoking, bronchiectasis, acid-fast bacilli smear positivity, and the M. abscessus strain significantly reduced microbiological cure rates. Serum CA 19-9 levels did not have a significant association with microbiological cure in a multivariate analysis. These findings suggest that the role of serum CA19-9 in predicting antibiotic treatment outcomes is limited, and that elevated CA19-9 does not necessarily indicate a poor outcome.

Early Microbiologic Markers of Pulmonary Tuberculosis Treatment Outcomes.

Rationale: Earlier biomarkers of pulmonary tuberculosis (PTB) treatment outcomes are critical to monitor shortened anti-TB treatment (ATT). Objectives: To identify early microbiologic markers of unfavorable TB treatment outcomes. Methods: We performed a subanalysis of 2 prospective TB cohort studies conducted from 2013 to 2019 in India. We included participants aged ⩾18 years who initiated 6-month ATT for clinically or microbiologically diagnosed drug-sensitive PTB and completed at least one follow-up visit. Sputum specimens were subjected to a baseline Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay, acid-fast bacilli (AFB) microscopy and liquid and solid cultures, and serial AFB microscopy and liquid and solid cultures at weeks 2, 4, and 8. Poisson regression was used to assess the impact of available microbiologic markers (test positivity, smear grade, time to detection, and time to conversion) on a composite outcome of failure, recurrence, or death by 18 months after the end of treatment. Models were adjusted for age, sex, nutritional status, diabetes, smoking, alcohol consumption, and regimen type. Results: Among 1,098 eligible cases, there were 251 (22%) adverse TB treatment outcomes: 127 (51%) treatment failures, 73 (29%) recurrences, and 51 (20%) deaths. The primary outcome was independently associated with the Xpert MTB/RIF assay (medium-positive adjusted incidence rate ratio [aIRR], 1.91; 95% confidence interval [CI], 1.07-3.40; high-positive aIRR, 2.51; 95% CI, 1.41-4.46), positive AFB smear (aIRR, 1.48; 95% CI, 1.06-2.06), and positive liquid culture (aIRR, 1.98; 95% CI, 1.21-3.23) at baseline; Week 2 positive liquid culture (aIRR, 1.47; 95% CI, 1.04-2.09); and Week 8 positive AFB smear (aIRR, 1.63; 95% CI, 1.06-2.50) and positive liquid culture (aIRR, 1.54; 95% CI, 1.07-2.22). There was no evidence of Mycobacterium tuberculosis growth in the Mycobacterium Growth Indicator Tube at Week 4 conferring a higher risk of adverse outcomes (aIRR, 1.25; 95% CI, 0.89-1.75). Conclusions: Our analysis identifies Week 2 respiratory mycobacterial culture as the earliest microbiologic marker of unfavorable PTB treatment outcomes.

Risk factors for microbiological persistence after 6 months of treatment for Mycobacterium intracellulare and its impact on the drug-resistance profile.

Patients with Mycobacterium intracellulare pulmonary disease are more likely to experience poor treatment outcomes if they have been observed with microbiological persistence after 6 months of treatment. This study aims to identify the risk factors for microbiological persistence and describe the changes in the minimum inhibitory concentration (MIC) during antimycobacterial treatment. This retrospective case-control study enrolled patients diagnosed with M. intracellulare pulmonary disease between April 2017 and September 2021 at Shanghai Pulmonary Hospital. Patients with positive cultures after 6 months of treatment (positive group) were matched by age and sex in a 1:1 ratio to patients with negative conversion (negative group). Totally, 46 pairs of patients were analyzed. Risk factors for microbiological persistence at month 6 were smoking, previous tuberculosis treatment, chronic lung diseases, a positive baseline acid-fast bacilli smear, and adverse drug reactions; the risk was reduced by a regimen containing ethambutol, ≥3 effective drugs, and a higher pre-treatment absolute lymphocyte count. Regarding the drug-resistance profile, the negative group had a higher proportion of susceptibility to clarithromycin (100.0% vs 84.8%, P = 0.012). Most isolates were susceptible or intermediate to amikacin in both groups (93.5% and 84.8%, respectively). Nine patients (16.4%, 9/55) had a change in the drug-resistance profile, including four who changed from clarithromycin susceptible to clarithromycin resistant, and the other three reversed. Two pairs of isolates had a change in resistance to amikacin. In conclusion, risk factors for microbiological persistence were identified, and the change in MIC values during antimycobacterial treatment indicated the need for monitoring to enable timely adjustment of the regimen.IMPORTANCENontuberculous mycobacteria pulmonary disease (NTM-PD) has been recognized as an important public health issue because of its increasing incidence globally, low cure rate, and high recurrence rate. NTM-PD has innate resistance to many first-line anti-tuberculous drugs, which limits the treatment options. Mycobacterium intracellulare is reportedly the most important pathogenic NTM and accounts for the highest proportion of NTM-PD in China. A previous study suggested that poor microbiological response after 6 months of treatment is predictive of treatment failure. The present study investigated the risk factors associated with persistent positive sputum cultures by treatment month 6 in patients with M. intracellulare pulmonary disease and the variation in minimum inhibitory concentration patterns in clinical settings. This information might help to identify patients at higher risk of treatment failure and enable the timely provision of necessary interventions.

Impact of Treatment on Long-Term Survival of Patients With Mycobacterium avium Complex Pulmonary Disease.

Whether antimicrobial treatment improves long-term survival in patients with Mycobacterium avium complex pulmonary disease (MAC-PD) is unclear. We analyzed survival in patients aged ≥18 years who were treated for MAC-PD at a tertiary referral center in South Korea between 1 January 2009 and 31 December 2020. Treatment exposure was divided into 4 time intervals: <6, ≥6 to <12, ≥12 to <18, and ≥18 months. Time-varying multivariable Cox proportional hazards models were used to calculate the all-cause mortality risk in each time interval. The model was adjusted for major clinical factors related to mortality including age, sex, body mass index, presence of cavities, erythrocyte sedimentation rate, positive acid-fast bacilli (AFB) smear, clarithromycin resistance, and comorbid conditions. A total of 486 patients treated for MAC-PD were included in the analysis. A significant inverse correlation was observed between mortality and duration of treatment (P for trend = .007). Long-term treatment (≥18 months) was significantly associated with reduced mortality (adjusted hazard ratio, 0.32 [95% confidence interval, .15-.71]). In subgroup analyses, patients with cavitary lesions (adjusted hazard ratio, 0.17 [95% confidence interval, .05-.57]) or positive AFB smears (0.13 [.02-.84]) at baseline maintained this significant inverse relationship between treatment duration and mortality. Long-term antimicrobial treatment should be actively considered in patients with progressive MAC-PD, especially in the presence of cavities or positive AFB smears indicative of high mycobacterial burden.

Treatment outcomes of multidrug-resistant TB with selective use of new drugs.

SETTING: This was a nationwide cohort study.OBJECTIVE: To assess the treatment outcomes in patients with multidrug-resistant TB (MDR-TB) who underwent treatment guided by a national TB expert review committee in South Korea.DESIGN: We enrolled all patients with MDR-TB submitted for approval for the use of new TB drugs, including bedaquiline and delamanid, from 2016 to 2019. Patients were classified into two groups: those on new TB drugs and those not on new TB drugs. We compared the final treatment outcomes between the groups and analysed the prognostic factors.RESULTS: Of a total of 785 patients, respectively 754 (96.1%) and 31 (3.9%) were classified into the "new TB drugs" group and "no new TB drugs" group. The new TB drugs group had a higher acid-fast bacilli smear positivity rate and higher resistance rate to second-line injectable drugs or fluoroquinolones. Of all the patients, 97.8% achieved culture conversion (97.7% vs. 100%), and 80.4% achieved treatment success (80.2% vs. 86.7%); there was no difference between the two groups.CONCLUSIONS: New drugs are currently recommended for use in all MDR-TB treatment regimens, and the use of new drugs, as determined by an expert committee, in mainly quinolone-susceptible MDR-TB, did not compromise the treatment success rate.

Surgical Intervention for Endobronchial Tuberculosis with Total Bronchial Occlusion: A Case Report

Introduction. Endobronchial Tuberculosis (EBTB) is a specific TB form affecting the tracheobronchial tree with microbial and histopathological evidence. Early diagnosis is essential to provide timely treatment and prevent complications but also proves difficult due to the low positive rate of acid–fast bacilli (AFB) staining of sputum smears and non–specific clinical and radiological findings. Case Illustration. We reported a 19–year–old man with a productive cough suspected of pulmonary tuberculosis, with a positive GeneXpert test and negative AFB smear. He received anti–tuberculosis drugs for six months. Although the symptoms initially seemed to improve, the patient complained of dyspnea during moderate activities in the sixth month. Chest x–ray showed complete atelectasis of the left lung. Further investigation with thorax computed tomography and confirmation with bronchoscopy revealed total occlusion of the left main bronchus. Left pneumonectomy was successfully conducted. Conclusion. Endobronchial tuberculosis may progress to an advanced stage despite adequate anti–tuberculosis drugs. Therefore, early diagnostic strategies are required to prevent the progression of the disease, particularly due to the insidious nature of its pathophysiological process

Sex differences in the impact of diabetes mellitus on tuberculosis recurrence: a retrospective national cohort study

ObjectivesWhether diabetes mellitus (DM) increases tuberculosis (TB) recurrence risk is debatable. We determined the effect of DM on TB recurrence. MethodsThis retrospective nationwide cohort study included patients with TB who successfully completed TB treatment during 2011-2017 and were followed up for TB recurrence until August 2020. We performed subdistribution hazard model analyses stratified by sex to assess DM risk related to TB recurrence after successful treatment. ResultsOf 199,571 participants who had received successful TB treatment, 47,952 (24%) had DM. There were more men (64.4%), positive acid-fast bacilli smears (35.9%), and positive cultures (49.5%) in the DM group. There were 6208 (3.1%) TB recurrences during 5.1 years of follow-up: 38.9% and 26.6% occurred 1 and 1-2 years after treatment completion, respectively. The recurrence rate was higher in the DM group (3.8%) than in the non-DM group (2.9%, P <0.0001). DM was associated with a higher TB recurrence risk, especially in men (adjusted hazard ratio 1.23, 95% confidence interval 1.15-1.32) but not in women (adjusted hazard ratio 0.96, 95% confidence interval 0.85-1.09). ConclusionThe TB recurrence rate after successful treatment was higher in patients with DM than in patients without DM. DM is associated with TB recurrence in men.

Acid-Fast Bacilli Smear Positivity and HBV, HCV, HIV, and Syphilis Co-infections between 2016 and 2019 in Mogadishu, Somalia

Although tuberculosis (TB) is a treatable disease, it continues to be an important health problem affecting societies worldwide. TB is one of the 10 most common causes of death worldwide today, despite the efforts of national organizations and the global struggle efforts of the World Health Organization (WHO), that have continued since its first establishment and exceeded seventy years. Somalia faces many negative factors that hinder the success of TB eradication programs, such as limitation of economic resources, lack of adequate infrastructure systems in the urban and rural regions, inadequacies in sheltering and nutrition, as well as instability, conflicts, and difficulties in accessing health care services. However, the country has been located in a rapidly developing region where socio-economic development and transformation has been experienced in many fields in recent years. This study includes the analysis of Acid Resistant Basil (ARB) smear examination results of patients admitted to a tertiary health center in the region where public health surveillance, screening programs, and treatment interventions have been disrupted for the last 30 years due to the aforementioned reasons. A total of 5,160 ARB test results of 3,909 patients admitted to the hospital with different medical reasons during the 4-year period between July 2016 and November 2019 were included in the study. The mean age was 43.3±21.8 years, with a range of &lt;1 to 97 years and the ARB test positivity rate was found to be %5.63 (220/3,909) in the study group. The positivity rate was 6.70% (158/2,199) in males and 3.99% (62/1,490) in females (p&lt;0.001). The group most affected by the infection (TB) were young and adult men between the ages of 10-40. HBsAg, anti-HCV and anti-HIV tests were also performed for approximately half of the patients who requested ARB test and the co-infection rates for hepatitis B, hepatitis C, and human immunodeficiency virus (HIV) were found as 9.68%, 2.46%, and 0.0%, respectively. These rates are compatible with the seroepidemiological situation of the mentioned viral infections in the region. The results also reveal the low frequency of HIV-TB co-infections in the Somali population, unlike other regions of sub-Saharan Africa. The co-infection rate for syphilis, in which fewer patients were tested, was found to be 2.27%. It was found that ARB positivity rates changed as 5.31%, 6.44%, and 5.63% between 2017-2019 and did not increase or decrease according to years; with the exception of 2016 (11.2%) when a small number of patients were admitted. Early diagnosis and early treatment of active cases are critical for the effectiveness of TB control programs. Despite certain limitations, the data presented in the study can be considered as a reference point for future studies.

The impact of diabetes mellitus on pulmonary TB.

To compare the clinical characteristics and laboratory results of pulmonary TB (PTB) patients with and without diabetes mellitus (DM) and the relationship between haemoglobin A1C (HbA1c) concentration and mycobacterial load at county level area in Sichuan Province, China. A retrospective study was performed from January 2018 to July 2019 inJianyang People's Hospital, Sichuan Province. Clinical characteristics and laboratory results of newly diagnosed TB patients were collected. Univariable and multivariable logistic regression analyses were performed. The Kruskal-Wallis test was used to compare HbA1c level and mycobacterial load. The final sample included 415 patients with TB, of whom 45 were diagnosed with DM (10.8%). Uni-variable logistic regression showed that PTB patients with concomitant DM were more likely to present with haemoptysis, positive acid-fast bacilli (AFB) smear, cavity, higher erythrocyte sedimentation rate (ESR), higher serum C-reactive protein (CRP), lower serum albumin (ALB), or higher fasting blood glucose (FBG). Multivariate logistic regression analyses showed that AFB smear positivity (OR 15.81, 95% CI 3.09-80.95) and FBG (OR 1.88, 95% CI 1.53-2.31) were independent risk factors of DMPTB. The mycobacterial load was heaviest when the HbA1c was 7.9 mmol/L (95% CI 7.35-11.1) and declined along with HbA1c rising up. But it has not been significantly associated with HbA1c. Patients with PTB over 45 years old, with haemoptysis, positive AFB, cavity, higher ESR, higher CRP, lower ALB or higher FBG are more likely to present with concomitant DM. Patients with PTB with these factors need to be targeted for DM screening. The mycobacterial load has not been significantly associated with HbA1c.

Characteristics, risk factors and outcomes of critically ill patients with active TB.

BACKGROUND: TB continues to impose a significant healthcare burden despite advancement in diagnostics and increased availability of effective antimicrobials. Recent years have seen a resurgence of the disease in association with increasing life expectancy and use of immunosuppressive therapy. Mortality remains high in TB patients requiring admission to critical care units.METHODS: We conducted a retrospective study in two public hospitals to determine factors associated with mortality in patients with TB requiring critical care admission. All patients aged ≥21 years with a diagnosis of active TB involving any organ system at the time of a critical care admission were eligible. The primary outcome measure was 30-day mortality.RESULTS: Over the study period of 4 years, 148 patients were identified. Overall 30-day mortality was 36.5%. Based on multivariate analysis, factors which independently correlated with 30-day mortality include higher APACHE II (Acute Physiology and Chronic Health Evaluation II) score, acid-fast bacilli smear positivity, initiation of anti-TB treatment prior to critical care admission and need for renal replacement therapy.CONCLUSION: TB in critically ill patients continues to be associated with significant mortality. The factors identified to be associated with poor survival outcomes in our study were largely related to greater disease burden and potential for suboptimal treatment.

Clinical Profile of Patients with Tuberculous Arthritis Admitted in a Tertiary Hospital in the Philippines

Background. Tuberculous arthritis is a rare extra-pulmonary manifestation of tuberculosis (TB) that can lead to significant disability when left untreated. This study described the clinical profile of patients with TB arthritis admitted in a tertiary hospital in the Philippines.&#x0D; Methods. We reviewed medical records of 65 patients with TB arthritis admitted in the Philippine General Hospital from 2006 to 2019.&#x0D; Results. Majority of patients were male (41, 63.0%) and the mean age upon diagnosis was 46.7 ± 1.7 years (20– 85). Majority (33, 50.8%) had underlying co-morbidities including hypertension (16, 24.6%), type 2 diabetes mellitus (10, 15.4%), and chronic kidney disease (8, 12.3%). A history of previous TB treatment (10, 15.4%), intake of immunosuppressive drugs (7, 10.8%), and trauma on affected joints (13, 20.0%) were also reported. Majority presented with chronic mono-arthritis (50, 76.9%) involving the knees (27, 41.5%) and hips (21, 32.3%) with a mean duration of symptoms of 20.9 ± 3.9 months. The most frequent initial diagnosis upon admission was septic arthritis (21, 32.3%). Confirmed septic arthritis (10, 15.6%), pulmonary TB (9, 14.3%), and disseminated TB (4, 6.3%) were also observed. Majority were diagnosed based on positive acid-fast bacilli (AFB) smear, polymerase chain reaction (PCR) for Mycobacterium tuberculosis, or synovium biopsy (34, 54.0%). Anemia (43, 68.3%) and elevated inflammatory biomarkers (erythrocyte sedimentation rate, ESR [36, 97.3%] and C-reactive protein, CRP [40, 87%]) were also seen in majority of patients. The most common radiographic findings on x-ray were joint space narrowing (42, 84.0%), soft tissue swelling (22, 44.0%), and erosions (21, 42.0%). The mean length of hospital stay was 23.8 ± 2.8 days (2–113). Majority underwent surgical interventions (35, 55.6%) including debridement (28, 80.0%) and arthrotomy (25, 71.4%). All received anti-tuberculosis treatment upon diagnosis.&#x0D; Conclusion. Majority of patients with TB arthritis in this study were male, with mean age in the 5th decade of life, presenting with mono-arthritis, anemia, elevated inflammatory markers, and radiologic findings of joint narrowing. All patients received medical treatment while more than half underwent surgery. There should be a high index of suspicion for TB arthritis in a patient from an endemic country presenting with chronic mono arthritis in weight-bearing joints to prevent delay in diagnosis and significant joint destruction and disability

TB prevalence in Zimbabwe: a national cross-sectional survey, 2014.

BACKGROUND: We conducted the first national TB prevalence survey to provide accurate estimates of bacteriologically confirmed pulmonary TB disease among adults aged ≥15 years in 2014.METHODS: A TB symptoms screen and chest X-ray (CXR) were used to identify presumptive TB cases who submitted two sputum samples for smear microscopy, liquid and solid culture. Bacteriological confirmation included acid-fast bacilli smear positivity confirmed using Xpert® MTB/RIF and/or culture. Prevalence estimates were calculated using random effects logistic regression with multiple imputations and inverse probability weighting.RESULTS: Of 43,478 eligible participants, 33,736 (78%) were screened; of these 5,820 (17%) presumptive cases were identified. There were 107 (1.9%) bacteriologically confirmed TB cases, of which 23 (21%) were smear-positive. The adjusted prevalences of smear-positive and bacteriologically confirmed TB disease were respectively 82/100,000 population (95% CI 47-118/100,000) and 344/100,000 (95% CI 268-420/100,000), with an overall all-ages, all-forms TB prevalence of 275/100,000 population (95% CI 217-334/100,000). TB prevalence was higher in males, and age groups 35-44 and ≥65 years. CXR identified 93/107 (87%) cases vs. 39/107 (36%) using the symptom screen.CONCLUSION: Zimbabwe TB disease prevalence has decreased relative to prior estimates, possibly due to increased antiretroviral therapy coverage and successful national TB control strategies. Continued investments in TB diagnostics for improved case detection are required.

193. Impact of COVID-19 Pandemic on Pulmonary Tuberculosis Evaluations and Diagnosis at a Large Safety Net Hospital in Los Angeles, California

BackgroundThere is significant global concern that the COVID-19 pandemic may negatively impact tuberculosis (TB) control. This is a descriptive analysis of TB evaluations and diagnosis during 2019 (pre COVID-19 period) and 2020 (COVID-19 period) at the largest safety net hospital in Los Angeles County (LAC+USC Medical Center). MethodsThe medical records of patients diagnosed with pulmonary TB from January 1, 2019 to December 31, 2020 were identified through laboratory and electronic medical records. We included all patients with ≥ 1 sputum positive result for Mycobacterium tuberculosis (MTB) culture and reviewed their Xpert MTB/RIF MTB PCR. ResultsTable 1 shows summary of results. During the COVID-19 period, the number of patients evaluated for pulmonary TB decreased by 64% compared to the previous year (Figure 1). The proportion of patients with culture-confirmed TB disease however, was nearly identical (P=0.913) (Table 1). Sputum acid-fast bacilli (AFB) smear positivity increased 52% to 64% during COVID-19 (P=0.324) and disease severity as measured by chest radiograph, was significantly higher during the COVID-19 period (P = 0.031) (Figure 2). Trend of sputum AFB smear and culture samples collected from January 1, 2019 to December 31, 2020. Summary of results of patients diagnosed with pulmonary TB from January 1, 2019 to December 31, 2020 at LAC+USC Medical Center. Results of two-sample test for proportions of 2019 vs 2020 for cavitary lesions, extent of disease, and sputum positive AFB smear microscopy.ConclusionThese preliminary results suggest that when compared to the previous year, the number of pulmonary TB evaluations decreased by 64% during the COVID period. Whereas the proportion of patients diagnosed with TB disease was similar, TB patients during the COVID-19 period had more advanced disease at diagnosis, as measured by sputum smear AFB microscopy and disease severity on chest radiograph (P=0.031). These data suggest potentially consequential interruptions and delays in pulmonary TB diagnosis during the COVID-19 period. Disclosures Susan Bulter-Wu, PhD , Cepheid (Consultant)

Analysis of the application of a gene chip method for detecting Mycobacterium tuberculosis drug resistance in clinical specimens: a retrospective study

Most Mycobacterium tuberculosis (Mtb) resistant to rifampicin (RIF) has mutations in the rpoB gene, while most Mtb resistant to isoniazid (INH) has mutations in the katG gene or inhA promoter. We used gene chip technology to detect mutations in these genes to determine the resistance of Mtb to RIF and INH. A total of 4148 clinical specimens with sputum smear positivity for acid-fast bacilli (AFB) were detected. Then, taking the results of the drug sensitivity test (DST) as the reference standard, the detection efficiency of sputum samples from different grades of positive smears was compared in detail. We found that the sensitivity of the gene chip method for detecting sputum samples with a grade ≥ AFB 2 + was higher than that of sputum samples with a grade ≤ AFB 1 + (P < 0.05). When the grade of the sample was ≤ AFB 1 +, the sensitivity of the gene chip method was 72.6% for RIF, 67.3% for INH, and 60.0% for MDR-TB. When the grade of the sample was ≥ AFB 2 +, the sensitivity of the gene chip method was 84.5% for RIF, 78.2% for INH, and 73.9% for MDR-TB. The results show that gene chip technology can be directly used to diagnose drug-resistant tuberculosis in clinical specimens, and the diagnostic efficiency for the detection of sputum specimens with a grade ≥ AFB 2 + is better than that of other sputum specimens.

Outcomes of Resectional Thoracic Surgery for the Treatment of Pulmonary Nontuberculous Mycobacterial Disease in 105 Patients in the United States

Outcomes of Resectional Thoracic Surgery for the Treatment of Pulmonary Nontuberculous Mycobacterial Disease in 105 Patients in the United States

Recurrent Tuberculosis Disease in Singapore.

BackgroundPreviously treated (ie, recurrent) tuberculosis (TB) cases account for approximately 7%–8% of incident TB globally and in Singapore. Molecular fingerprinting has enabled the differentiation of these patients into relapsed or reinfection cases.MethodsPatient demographics, disease characteristics, and treatment information were obtained from the national TB notification registry and TB Control Unit. We performed a retrospective, case-control study to evaluate factors associated with recurrent TB disease in Singapore citizens and permanent residents with culture-positive TB from 2006 to 2013 and who developed a second episode of culture-positive TB up to 2016 using multivariable logistic regression analyses.ResultsNinety-one cases with culture-positive first and recurrent TB disease episodes were identified. Recurrent TB was associated with age ≥60 years (adjusted odds ratio [aOR], 1.98 [95% confidence interval {CI}, 1.09–3.61), male sex (aOR, 2.29 [95% CI, 1.22–4.51]), having concomitant pulmonary and extrapulmonary TB (aOR, 3.10 [95% CI, 1.59–6.10]) and extrapulmonary TB alone (aOR, 3.82 [95% CI, 1.12–13.31]), and was less likely in non-Malays (aOR, 0.52 [95% CI, .27–.99]). DNA fingerprinting results for both episodes in 49 cases differentiated these into 28 relapsed and 21 reinfection cases. Relapse was associated with having concomitant pulmonary and extrapulmonary TB (aOR, 9.24 [95% CI, 2.50–42.42]) and positive sputum acid-fast bacilli smear (aOR, 3.95 [95% CI, 1.36–13.10]).ConclusionsRelapse and reinfection contributed to 57% and 43%, respectively, of recurrent TB in Singapore. Our study highlights the underappreciated association of concomitant pulmonary and extrapulmonary TB as a significant risk factor for disease relapse.

LARYNGEAL TUBERCULOSIS – A NEGLECTED DISEASE THAT CAN MIMIC LARYNGEAL CARCINOMA

Laryngeal tuberculosis is a form of extra-pulmonary tuberculosis that occurs in only 1% of all tuberculosis cases, with the mortality rate of less than 2%. It can be a complication of pulmonary or some other form of extra-pulmonary tuberculosis (via bronchogenic, haematogenic or lymphagenic spread of bacilli), or the larynx can be the only organ affected after the direct invasion of Mycobacterium tuberculosis. Clinical, laryngoscopic and radiological findings of laryngeal tuberculosis tend to mimic laryngeal cancer, delaying the appropriate treatment. In this paper, we present a case of the laryngeal and pulmonary tuberculosis which was primarily diagnosed and almost treated as laryngeal carcinoma. An 84 years old Caucasian male presented with a 3-months history of hoarseness, odynophagia, dysphagia, cough with expectoration and weight loss. After the laryngoscopy and biopsy of the laryngeal ulceration, a squamous cell carcinoma was suspected. However, chest X-ray and CT scan detected pulmonary infiltrates, while the positive sputum smear for acid-fast bacilli was obtained and the sputum cultures grew Mycobacterium tuberculosis. Detailed histopathological analysis of the biopsies was in accordance with tuberculosis, and no signs of timorous tissue were found. After the end of the proposed antituberculous treatment, the patient reported no symptoms of the diseases, laryngoscopic findings showed no signs of neoplastic tissue, and CT findings showed partial radiological regression. Distinguishing laryngeal carcinoma and tuberculosis can be very challenging, even after obtaining histopathological material. Nevertheless, biopsies should be taken from all suspicious lesions and at multiple sites and Ziehl-Neelson staining of sputum and bioptic tissue is necessary. Otorhinolaryngologists should always consider tuberculosis in differential diagnosis of laryngeal lesions, especially nowadays when the incidence of laryngeal tuberculosis is increasing in developing countries.

English

BACKGROUND Tuberculosis is often more difficult to diagnose and more complicated to treat among people who are human immunodeficiency virus (HIV) positive. This study was conducted to assess the clinical, microbiological, laboratory and radiological spectrum of tuberculosis (TB) in HIV seropositive patients, and explore its possible correlation with their CD4 count. METHODS A total of 104 patients who were western blot positive for HIV and co-infected with tuberculosis were studied in Salem district of Tamil Nadu. A detailed history was obtained and patients were examined clinically. CD4 count, sputum smear for acid fast bacilli (AFB), chest x-ray, and tuberculin test, were done along with other relevant investigations. The relationship between CD4 count, and the type of tuberculosis, sputum smear, chest x-ray, and tuberculin test, were analysed statistically, and P &lt; 0.05 was considered significant. RESULTS Most of the patients were between 30 to 39 years. Males (84.6 %) outnumbered females (15.4 %). Pulmonary tuberculosis alone was seen in 47 patients, while extra pulmonary tuberculosis in 36 cases, and both pulmonary and extra pulmonary occurred in 21 cases. They had a mean CD4 count of 237.7 cells / μL, 135.2 cells / μL and 120.9 cells / μL respectively. Extrapulmonary tuberculosis and combined forms were associated with lower CD4 counts (P-value 0.005). The mean CD4 count of sputum positive, sputum negative, and multiple drug resistant (MDR) tuberculosis were 294.2, 168.3 and 90.2 cells / μL respectively. Lower CD4 count was associated with sputum - ve TB (P &lt; 0.041). Lower CD4 counts were associated with atypical chest X-ray findings (P &lt; 0.006) and negative tuberculin test (P &lt; 0.001). CONCLUSIONS Sputum smear positivity for AFB decreases as CD4 count reduces. Involvement of lungs tend to be atypical in immunocompromised patients. The diagnosis of TB in HIV positive individuals is complex and a high index of suspicion is needed. KEYWORDS HIV, Tuberculosis, CD4 Cell Count, Sputum Smear for AFB, Chest X-Ray