Positive Culture For Mycobacterium Tuberculosis Research Articles

Mirage de tuberculose in the 21st century.

The occurrence of transient culture positivity for Mycobacterium tuberculosis (MTB), known as mirage de tuberculose, poses significant challenges in understanding its spectrum and implications. Here, we report a case of transient culture positivity, oscillating between detectable and non-detectable MTB cultures with minimal radiological features and review the literature on this phenomenon. The scarcity of scientific literature on this subject stems from the inherent impossibility of systematically studying mirage de tuberculose. Ethical and public health concerns prevent withholding treatment to monitor spontaneous reversion to negative cultures. Based on the literature, we estimate that mirage de tuberculose occurs in approximately one-third of individuals infected with MTB who exhibit no symptoms. Despite the inherently limited nature of these findings, they suggest that the significance of mirage de tuberculose may be greater than currently perceived. Managing cases of mirage de tuberculose presents formidable challenges from a public health perspective. Striking a balance between prompt treatment initiation to prevent transmission and the risk of unnecessary treatment requires careful consideration. In conclusion, mirage de tuberculose remains a poorly understood clinical entity with very limited literature available. Advancing research and interdisciplinary collaborations are essential to unravel the intricacies of this phenomenon and develop effective strategies to address its public health challenges.

Second Nationwide Tuberculosis Outbreak Caused by Bone Allografts Containing Live Cells - United States, 2023.

During July 7-11, 2023, CDC received reports of two patients in different states with a tuberculosis (TB) diagnosis following spinal surgical procedures that used bone allografts containing live cells from the same deceased donor. An outbreak associated with a similar product manufactured by the same tissue establishment (i.e., manufacturer) occurred in 2021. Because of concern that these cases represented a second outbreak, CDC and the Food and Drug Administration worked with the tissue establishment to determine that this product was obtained from a donor different from the one implicated in the 2021 outbreak and learned that the bone allograft product was distributed to 13 health care facilities in seven states. Notifications to all seven states occurred on July 12. As of December 20, 2023, five of 36 surgical bone allograft recipients received laboratory-confirmed TB disease diagnoses; two patients died of TB. Whole-genome sequencing demonstrated close genetic relatedness between positive Mycobacterium tuberculosis cultures from surgical recipients and unused product. Although the bone product had tested negative by nucleic acid amplification testing before distribution, M. tuberculosis culture of unused product was not performed until after the outbreak was recognized. The public health response prevented up to 53 additional surgical procedures using allografts from that donor; additional measures to protect patients from tissue-transmitted M. tuberculosis are urgently needed.

Tuberculous peritonitis: an analysis of case series of 49 consecutive patients

Objectives: The incidence of tuberculous peritonitis has been reported between 0.1% and 0.7% among all tuberculosis types. This study, it was aimed to evaluate the cases with tuberculous peritonitis, which has an important place in the differential diagnosis of patients with ascites, clinically, biochemically, microbiologically, and histopathologically. Methods: : Forty-nine patients with a definite clinical, radiological, and histopathological diagnosis of tuberculous peritonitis, which formed the basis of our study, were analyzed retrospectively. Results: The mean age of patients with tuberculous peritonitis was found to be 39.45 ± 19.02 years. Purified-protein derivative (PPD) was positive in 23 (72%) of 32 patients with tuberculous peritonitis whose PPD results were recorded, in 9 (28%) PPD results were evaluated as anergic or negative. QuantiFERON-TB Gold In-Tube (QFT-GIT) test was sent in 10 of the patients, the result was positive in 9 (90%) patients and negative in 1 (10%) patient. There were 32 patients in whom tuberculosis polymerase chain reaction (PCR) was studied from ascitic fluid, 7 (22%) of the patients were PCR positive and 25 (78%) negative. Mycobacterium tuberculosis culture positivity was found in 18 (69%) of 26 patients who were biopsied. In total, 29 (59%) of the patients had M. tuberculosis culture positivity. Conclusions: Tuberculous peritonitis constitutes a public health problem in endemic regions of the world and tuberculous peritonitis should be considered in patients presenting with ascites. Despite all diagnostic difficulties, necessary tests, especially peritoneal biopsy, should be performed for early diagnosis, and it should not be forgotten that early initiation of treatment is very important in terms of morbidity and mortality of the disease.

The effect of previous SARS-CoV-2 infection on systemic immune responses in individuals with tuberculosis.

The impact of previous SARS-CoV-2 infection on the systemic immune response during tuberculosis (TB) disease has not been explored. An observational, cross-sectional cohort was established to evaluate the systemic immune response in persons with pulmonary tuberculosis with or without previous SARS-CoV-2 infection. Those participants were recruited in an outpatient referral clinic in Rio de Janeiro, Brazil. TB was defined as a positive Xpert-MTB/RIF Ultra and/or a positive culture of Mycobacterium tuberculosis from sputum. Stored plasma was used to perform specific serology to identify previous SARS-CoV-2 infection (TB/Prex-SCoV-2 group) and confirm the non- infection of the tuberculosis group (TB group). Plasmatic cytokine/chemokine/growth factor profiling was performed using Luminex technology. Tuberculosis severity was assessed by clinical and laboratory parameters. Participants from TB group (4.55%) and TB/Prex-SCoV-2 (0.00%) received the complete COVID-19 vaccination. Among 35 participants with pulmonary TB, 22 were classified as TB/Prex-SCoV-2. The parameters associated with TB severity, together with hematologic and biochemical data were similar between the TB and TB/Prex-SCoV-2 groups. Among the signs and symptoms, fever and dyspnea were significantly more frequent in the TB group than the TB/Prex-SCoV-2 group (p < 0,05). A signature based on lower amount of plasma EGF, G-CSF, GM-CSF, IFN-α2, IL-12(p70), IL-13, IL-15, IL-17, IL-1β, IL-5, IL-7, and TNF-β was observed in the TB/Prex-SCoV-2 group. In contrast, MIP-1β was significantly higher in the TB/Prex-SCoV-2 group than the TB group. TB patients previously infected with SARS-CoV-2 had an immunomodulation that was associated with lower plasma concentrations of soluble factors associated with systemic inflammation. This signature was associated with a lower frequency of symptoms such as fever and dyspnea but did not reflect significant differences in TB severity parameters observed at baseline.

Real time endobronchial ultrasound transbronchial needle aspiration for the diagnosis of tuberculous intrathoracic lymphadenopathy: Saudi Arabian Western region experience.

To assess the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for presumptive tuberculosis (TB) patients with intrathoracic enlarged lymph nodes in a country with low to moderate TB incidence. Thirty-one patients with clinical features of TB and intrathoracic lymphadenopathy, who had EBUS-TBNA sampling and final confirmation of intrathoracic TB lymphadenopathy, were retrospectively reviewed over an 8-year period. Routine clinical and laboratory evaluations including computerized tomography scans were performed before the EBUS-TBNA. Sociodemographic characteristics, clinical profile, pathological, and microbiological findings were collected. The EBUS-TBNA confirmed TB diagnosis in 26 (83.9%) subjects with a consistent pathological finding or positive culture of Mycobacterium tuberculosis. Pathological analysis had findings consistent with TB in 25 (80.6%) patients. Culture of the EBUS-TBNA sample was positive for Mycobacterium tuberculosis in 12 (38.7%) patients. Other supportive investigations like purified protein derivative (PPD) skin test was positive in 28 (90.3%) participants. Overall, the sensitivity of the EBUS-TBNA alone was 83.9%. No complications were recorded during the procedure. The EBUS-TBNA aspirate culture positivity was significantly related to having a larger size lymph node (p=0.048) only, while PPD positivity was significantly related to baseline and clinical features of the participants. The EBUS-TBNA demonstrated effective utility and safety in the evaluation and diagnosis of intrathoracic TB lymphadenopathy among individuals with compatible symptoms in a country with low-moderate TB-incidence.

Drug Resistance of Mycobacterium tuberculosis Based on Whole-Genome Sequencing in the Yi Ethnic Group, Sichuan Province, China.

This study investigated drug-resistant tuberculosis (DR-TB) in the Yi ethnic group. The study was designed to identify risk factors for DR-TB and its relationship with HIV/AIDS. To establish the resistance to antituberculosis drugs, whole-genome sequencing (WGS) was performed using culture-positive Mycobacterium tuberculosis samples collected from people of the Yi ethnic group from March 2019 to March 2021. Baseline characteristics were obtained from China's tuberculosis surveillance system. A total of 116 M. tuberculosis strains were included in the final analysis. Lineage 2.2 (75.86%) was the dominant sublineage, followed by lineage 4.5 (18.97%) and lineage 4.4 (5.17%). The rates of rifampicin-resistant (RR-TB), multidrug-resistant (MDR-TB), and preextensively drug-resistant TB (pre-XDR-TB) were 18.97%, 10.34%, and 6.03%, respectively. Drug-resistant strains were not found in the elderly (age ≥ 65 years). The proportions of RR/MDR-TB and pre-XDR-TB cases among re-treatment patients were higher than those among new patients (χ 2 = 12.155, P = 0.003; χ 2 = 22.495, P = 0.001, respectively). The pre-XDR-TB case proportions were higher among female patients than among males and higher among referred patients (χ 2 = 5.456, P = 0.032; χ 2 = 15.134, P = 0.002, respectively). The rates of RR/MDR-TB and pre-XDR-TB did not differ appreciably among groups with different HIV infection statuses nor lineage populations. DR-TB poses a serious challenge to the Yi ethnic group. Re-treatment patients, women, and referred patients were at high risk of MDR/RR-TB or pre-XDR-TB while HIV and lineage 2 had negligible association with drug resistance. Whole-genome sequencing should be used to guide the design of treatment regimens and to tailor public interventions.

Culture filtrate supplementation can be used to improve Mycobacterium tuberculosis culture positivity for spinal tuberculosis diagnosis.

Culture remains the gold standard to diagnose spinal tuberculosis (STB) despite the paucibacillary nature of the disease. Current methods can take up to 42 days to yield a result, delaying the ability to rapidly detect drug resistance. Studies have demonstrated the use of supplementation with culture filtrate (CF) from an axenic culture of Mycobacterium tuberculosis (Mtb) as a source of growth factors to improve culture rates. Our objective was to test a modified culture assay, utilizing CF supplemented media (CFSM), to improve culture positivity rates for suspected STB. Twelve patients with suspected STB were assessed by conventional culture (BACTEC™ MGIT 960), GeneXpert™ and standard histopathological examination. Spinal biopsies were taken from areas of diseased vertebral tissue or abscess, predetermined from MRI. Additional biopsies were obtained to assess CFSM for improved detection and faster culture of Mtb. All cases were diagnosed as STB and treated empirically for tuberculosis based on either bacteriological evidence (GeneXpert™, MGIT and/or CFSM positive), or based on clinical presentation. 5 specimens (45.45%) were positive for Mtb DNA as detected by GeneXpert™ and 1 specimen (8.33%) was cultured using MGIT (time to detection; 18 days). CFSM was able to culture 7 specimens (58.3%), with all CFSM positive specimens yielding a culture within 14 days. Two samples were positive only using the CFSM assay pointing to additional yield for diagnostic workup. Modification of standard culture can improve detection of Mtb and reduce time to positivity in individuals with STB where culture material is a requirement.

Clinical, laboratory, and radiographic aspects of patients with pulmonary tuberculosis and dysglycemia and tuberculosis treatment outcomes.

To analyze the association of dysglycemia with clinical, laboratory, and radiographic characteristics of patients with pulmonary tuberculosis (PTB), as well as with their tuberculosis treatment outcomes. This was a longitudinal study involving 140 patients diagnosed with PTB (positive cultures for Mycobacterium tuberculosis or positive Xpert MTB/RIF results from sputum samples). Patients were evaluated at diagnosis (M0), after completing the second month of treatment (M2), and at the end of treatment (MEND). At M0, the patients were classified into three groups: normoglycemia+PTB (NGTB); pre-diabetes mellitus+PTB (PDMTB), and diabetes mellitus+PTB (DMTB), in accordance with glycated hemoglobin levels (< 5.7%, 5.7%-6.4%, and ≥ 6.5%, respectively). Treatment outcomes were classified as favorable (cure or treatment completion) and unfavorable (death, loss to follow-up, or treatment failure). In our sample, 76 patients (61.4%) had dysglycemia, 20 of whom (14.3%) had DM at M0. The patients with dysglycemia, in comparison with those in the NGTB group, more frequently presented with positive sputum smear microscopy (94.2% vs. 75.9%; p = 0.003); cavities (80.2% vs. 63.0%; p = 0.03); bilateral lesions (67.4% vs. 46.0%; p = 0.02); and higher median of affected thirds of the lungs (3.0 vs. 2.0; p = 0.03) on chest radiography. No significant differences regarding outcomes were found among the groups, but tuberculosis lethality was higher in the DMTB group than in the PDMTB and NGTB groups (20% vs. 2.2%). PTB patients with dysglycemia had laboratory and radiographic manifestations indicative of more advanced disease, and the risk of death was higher in the DMTB group. These findings reinforce the recommendation for early screening for DM in patients with newly diagnosed tuberculosis in order to reduce the risk of death during treatment.

Bronchial Washing Using a Thin Versus a Thick Bronchoscope to Diagnose Pulmonary Tuberculosis: A Randomized Trial.

This study was performed to evaluate the efficacy of using a thin bronchoscope for the diagnosis of pulmonary tuberculosis (PTB). Between March 2019 and November 2021, we prospectively enrolled participants with suspected PTB whose sputum acid-fast bacilli (AFB) smear and tuberculosis (TB) polymerase chain reaction (PCR) tests were negative or who could not produce self-expectorated sputum. Participants were randomized to a control group (bronchial washing [BW] using a 5.9-mm conventional bronchoscope guided by chest computed tomography) or an investigational group (BW using a 4.0-mm thin bronchoscope under virtual bronchoscopic navigation guidance). The primary outcome was detection of TB in BW fluid, defined as a positive result in the Xpert MTB/RIF assay. The secondary outcomes included AFB smear and Mycobacterium tuberculosis culture positivity, time to treatment initiation, and bronchoscopy-related complications. In total, 85 participants were included in the final analysis (43 in the control group and 42 in the investigational group). Twenty-three and 29, respectively, were finally diagnosed with PTB. The TB detection rate in BW fluid was higher in the investigational group (72.4% vs 43.5%, P = .035). Mycobacterium tuberculosis culture positivity was also higher in the investigational group (79.3% vs 52.2%, P = .038). No participants required premature bronchoscopy termination because of complications. Of the participants with PTB, the time to treatment initiation was shorter in the investigational group (median, 2.0 days vs 4.0 days, P = .001). BW using a thin bronchoscope increases the TB detection rate in patients with PTB compared to conventional bronchoscopy. Clinical Trials Registration.ȃNCT03802812.

Tuberculosis and diabetes: increased hospitalisations and mortality associated with renal impairment.

Diabetes mellitus (DM) triples a person's risk of active tuberculosis (TB) and is associated with increased mortality. It is unclear whether diabetes status and/or the associated renal dysfunction is associated with poor TB outcomes in New Zealand, which has high diabetes screening. To characterise the population of TB-DM and TB-alone to assess the effect of diabetes status and renal function on hospitalisation and mortality. Clinical records from all adult patients diagnosed with TB in Auckland over a 6-year period (2010-2015) were reviewed. Baseline demographics, clinical presentation and microbiological data were assessed to compare the rates of hospitalisation and mortality between those with TB-DM and TB-alone. Statistical significance was defined as P < 0.05. A total of 701 patients was identified with TB; 120 (17%) had an unknown diabetes status and were excluded, and 135 had co-existing diabetes. The TB-DM and TB-alone groups had similar distribution of TB site and proportions of Mycobacterium tuberculosis culture positivity. Univariate analysis showed TB-DM patients had statistically significantly higher proportions of acute hospitalisation and mortality. Multivariate logistic regression showed only a reduced estimated glomerular filtration rate (eGFR) accounted for the higher rates of hospitalisation, with the odds of hospitalisation increasing by 2% for every unit decrease in eGFR. The odds of mortality increased by 6% for every year increase in age, and the odds of mortality increased by 3% for every unit reduction in eGFR. Diabetes is associated with higher TB hospitalisation and mortality; however, this is likely mediated by increased age and chronic kidney disease.

Effect of time, temperature and pH on Mycobacterium tuberculosis culture positivity of gastric aspirate: An experimental study

BackgroundThe culture of gastric aspirate (GA) has been used for bacteriological confirmation of pulmonary tuberculosis in children and patients who are unable to expectorate. Sodium bicarbonate neutralization of gastric aspirates is commonly recommended to increase culture positivity. We aim to study Mycobacterium tuberculosis (MTB) culture positivity of GA collected from confirmed case of pulmonary tuberculosis after storing it at different temperature, pH & time. MethodsGA specimens from 865 patients of either sex predominately non-expectorating children/adults with suspected pulmonary TB were collected. Gastric lavage was performed in the morning after an overnight fasting (at least 6hrs fasting). The GA specimens were tested by CBNAAT (GeneXpert) and AFB microscopy & those who were positive on CBNAAT were further processed with MTB culture on Growth Indicator Tube (MGIT™) culture. pH neutralized and non-neutralized CBNAAT positive GA specimens were culture within 2 hours of collection and 24 hours after storage at 4 °C & room temperature. ResultsMTB was detected in 6.8% of collected GA specimens by CBNAAT. Culture positivity of neutralized GA specimens when processed within 2 hours of collection, was higher compared to paired non-neutralized GA specimens. Neutralized GA specimens had higher contamination rate than non-neutralized GA specimens. Storage of GA specimens at $Deg C had better culture yield than those stored at room temperature. ConclusionEarly neutralization of acid in Gastric aspirate (GA) is essential for better culture positivity of M. tuberculosis (MTB). If there is a delay in processing GA, it should be kept at 4 °C after neutralization; however, positivity decreases with time.

Pigmented hypopyon – An approach to management

A 60-year-old Indian male presented with diminution of vision in the right eye for 3 months duration. Subsequent evaluation showed signs of granulomatous anterior uveitis, scleral thinning and brown colored pigmented hypopyon in the right eye. Patient was thoroughly evaluated for all possible associations of pigmented hypopyon. He was found to have positive mantoux test, QTB Gold test, positive culture for Mycobacterium tuberculosis on Middlebrook 7H9 medium and positive MPT64 antigen test confirming the diagnosis of intraocular tuberculosis. He was treated with anti-tubercular treatment and oral steroids and subsequently with dexamethasone intravitreal implant. He had complete resolution of pigmented hypopyon with improvement in visual acuity. This case highlights an approach to management in cases of pigmented hypopyon and also highlights that an aggressive management in such cases is pertinent to saving the eye and vision.

Tuberculosis in sickle cell disease patients

ObjectiveTuberculosis (TB) disease has rarely been reported in patients with sickle cell disease, but it is associated with an increased risk of bacterial infections. In France, sickle cell disease is frequent in populations with the highest prevalence of TB disease. We aimed to highlight clinical aspects of TB disease in patients with sickle cell disease. Patients and methodsOver a 10-year period, we retrospectively included all adults with sickle cell disease who had a positive culture for Mycobacterium tuberculosis managed in the adult sickle cell center of Henri-Mondor hospital. Sickle cell patients with TB disease were matched for comparison to adults without hemoglobinopathy and with documented TB disease in a 1:2 ratio. Logistic regression mixed models were performed. ResultsTwelve patients with sickle cell disease and documented TB disease (median age: 29years; IQR [25–34]) were compared to 24 non-sickle cell patients (median age: 33years; IQR [27.5–38.5]). Baseline characteristics were similar between groups except for sickle cell disease. Ten of the 12 patients with sickle cell disease had pulmonary TB. TB disease characteristics were similar between sickle cell and non-sickle cell patients although sickle cell patients had fewer positive sputum smears for acid-fast bacilli (P=0.003) and fewer lung cavitations (P=0.03). ConclusionsTB disease in sickle cell patients was globally similar to non-sickle cell patients, even though less infectious. Regular follow-up in specialized centers might allow for earlier TB disease diagnosis in sickle cell patients.

Tuberculosis espinal: diagnóstico y manejo

Spinal tuberculosis accounts for 50 % of all cases of osteoarticular tuberculosis, causing disability (due to neurological complications) and deformity if left untreated. This disease is suspected based on the patient’s medical history, clinical manifestations and radiological findings. It is diagnosed by positive cultures for Mycobacterium tuberculosis, the histopathological characteristics of the condition and/or acid-fast bacilli (AFB)-positive smear tests. The main differential diagnosis of spinal tuberculosis is pyogenic spondylodiscitis. Magnetic resonance imaging is the appropriate imaging test to assess the neurological involvement and study the differential diagnosis of the disease. The main treatment is antituberculous chemotherapy, but surgery can be adjunctive in cases of complicated spinal tuberculosis. The decision of which treatment to implement depends on the neurological deficit and the resulting deformity. Laminectomy alone is contraindicated and arthrodesis implants can be used during the active infection. Despite treatment, 8 % of the patients with neurological deficit do not recover.

A Whole-Genome Sequencing-Based Study to Delineate the Risk and Characteristics of Tuberculosis Transmission in an Insular Population Over 10 Years in Shanghai.

BackgroundTuberculosis (TB) has remained a tough problem in China. This study aims to identify the risk of tuberculosis transmission and to assess its characteristics.MethodsWe performed a molecular epidemiological study for patients with culture-positive Mycobacterium tuberculosis (M. tuberculosis) in Shanghai, from 2009 to 2018. Demographic information was obtained from the Tuberculosis Information Management System. Whole-genome sequencing (WGS) was conducted with a threshold of 12 single-nucleotide polymorphisms (SNPs) to distinguish the genomic cluster. To analyze the characteristics of TB transmission, the contact investigation for clustered cases was performed.ResultsIn total, 94 (27.25%) of the 345 enrolled patients were grouped into 42 genomic clusters, indicating local transmission of M. tuberculosis strains. Compared to a health system delay <14 days, patients with a health system delay ≥14 days [adjusted odds ratios (AOR) = 2.57, 95% confidence interval (CI): 1.34–4.95] were more likely to be clustered. Patients under 65 years old (AOR = 3.11, 95% CI: 1.76–5.49), residents (AOR = 2.43, 95% CI: 1.18–4.99), and Beijing genotype strains (AOR = 3.35, 95% CI: 1.32–8.53) were associated with increased risk of clustering. Interestingly, patients with resistance to isoniazid (AOR = 2.36, 95% CI: 1.15–4.88) had a higher risk of transmission. Sixteen confirmed/probable epidemiological links were identified. Local transmission of imported cases and household transmission were prominent.ConclusionHealth system delay is a crucial factor for TB transmission. Patients with resistance to isoniazid should be priority targets for contact investigation to reduce transmission.

Prevalence of Diabetes Mellitus in Patients with Tuberculosis: A Prospective Cohort Study

BackgroundDiabetes mellitus (DM) and poor glycemic control significantly increase the risk of tuberculosis (TB) and adverse outcomes after TB treatment. However, DM screening is not universally performed. MethodPatients diagnosed with TB were enrolled and tested for fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) within 3 months after TB diagnosis. ResultsA total of 216 patients with TB were included. Median (IQR) age was 60 years (53-73), and 57% were male. The prevalence of DM was 42.6%. Patients with TB with DM were more likely to have other comorbidities (76% vs 52%, p<0.001), a higher proportion of positive sputum acid-fast bacilli (AFB) (27% vs 11%, p=0.001), and a positive culture for Mycobacterium tuberculosis in bronchoalveolar lavage (10% vs 3%, p=0.045) compared to those withour DM. Patients with TB with DM had a lower cure rate at 6 months (30% vs 57%, p=0.001), a higher death rate at 6 months (14% vs 3%, p=0.016), and a higher proportion of treatment complications (22% vs 10%, p=0.014) than those without DM. Having pre-existing underlying impaired fasting glucose (odds ratio [OR] 8.03, p<0.001) and positive sputum AFB (OR 7.41, p<0.001) were associated with newly diagnosed DM cases among patients with TB. ConclusionsThe prevalence of DM in patients with TB in our study's setting was unexpectedly high. Patients with TB with DM had unfavorable outcomes compared with those without DM. We recommend routinely screening for DM in all patients with newly diagnosed TB.

Comparison of Tuberculin Skin Test and QuantiFERON-TB Gold Test in Children

Objective: Interferon-γ release tests (IGRAs) and tuberculin skin testing (TST) are important helpful tests for diagnosing tuberculosis (TB) disease in children. It was aimed to compare the sensitivity and compatibility of QuantiFERON-TB Gold In-tube test (QFT) and TST used in children with TB and Latent tuberculosis infection (LTBI). Material and Methods: A total of 118 patients between September 2018 and January 2020 were included in the study prospectively to determine the case characteristics related to the performance of the tests, and to measure the sensitivity of these tests. Results : A total of 118 patients were included in the study; and 13 (11%) patients presented with pneumonia symptoms and 7 (6%) patients were diagnosed with TB in active TB Contact Screening. TB diagnosis was made 20% microbiologically. Mycobacterium tuberculosis culture positivity was found to be 10%. None of the patients had acid-resistant bacilli positivity. The male / female rate was 74/44 in our study (p = 0.006). The median age was found to be 14 (1.17-19.2 years) in males, and 12 (0.33 -17.9 years) in females. The mean age of the LTBI Group was higher than the TB Group at significant levels (p <0.05), and was similar to the non-infected group (p>0.05). A total of 53.5% of the patients had a history of meeting someone with tuberculosis, and 97 children were vaccinated with BCG (82.2%). TST and QFT positivities were 19.5% and 22%, respectively. The most common radiological finding that was detected was consolidation areas. While there was moderate compliance between TST and IGRA test in patients with TB diagnosis (kappa =0.50, p=0.025), no compliance was found between tests in LTBI patients. In patients who were diagnosed with TB and LTBI, the sensitivity of TST was found to be 51.1%, and the sensitivity of QFT was found to be 60.4%. Conclusion: TST seems to continue as the most preferred method of diagnosis in rural areas with limited resources and poor laboratory infrastructure due to the costs and technical considerations.

Prevalence of extensively drug-resistant tuberculosis in a Chinese multidrug-resistant TB cohort after redefinition

ObjectivesRecently, the definition of extensively drug-resistant TB (XDR-TB) has been revised. In this study, we conducted a descriptive and retrospective study to determine the prevalence of XDR-TB in a Chinese multidrug-resistant TB (MDR-TB) cohort.MethodsBroth microdilution method was performed to determine in vitro susceptibilities of Mycobacterium tuberculosis (MTB) isolates to (FQs), bedaquiline (BDQ) and linezolid (LZD). The putative drug target genes conferring drug resistance were screened by DNA sequencing.ResultsA total of 425 MDR-TB isolates were included from 13 pilots in China. LZD and BDQ resistance were noted in 30 (7.1%) and 10 (2.4%) isolates. On the basis of latest definitions, 114 (26.8%) were MDR-TB, 282 (66.4%) were pre-XDR-TB, and 29 (6.8%) were XDR-TB. Among 311 FQ-resistant isolates, 265 harbored genetic mutations within QRDRs. The most common mutations were observed at codon 94 of gyrA, accounting for 47.2% of FQ-resistant MTB isolates. Only mutations within the Rv0678 gene were found to confer BDQ resistance in our cohort, conferring 40.0% of BDQ resistance. For LZD resistance, 53.3% of LZD-resistant isolates carried genetic mutations in rplC or 23S rRNA. The most frequent mutation was Cys154Arg in the rplC gene. In addition, we recorded two MDR-TB patients with resistance to both BDQ and LZD, of which one patient experienced continuous positive culture of MTB despite inclusion of efficacious moxifloxacin.ConclusionOur results demonstrate that the low prevalence of XDR-TB holds great promise for MDR-TB treatment with WHO-endorsed regimens containing BDQ-LZD combination, whereas the high prevalence of FQ-resistance in MDR-TB patients warrants national attention.

Pre-Treatment Neutrophil Count as a Predictor of Antituberculosis Therapy Outcomes: A Multicenter Prospective Cohort Study.

BackgroundNeutrophils have been associated with lung tissue damage in many diseases, including tuberculosis (TB). Whether neutrophil count can serve as a predictor of adverse treatment outcomes is unknown.MethodsWe prospectively assessed 936 patients (172 HIV-seropositive) with culture-confirmed pulmonary TB, enrolled in a multicenter prospective cohort study from different regions in Brazil, from June 2015 to June 2019, and were followed up to two years. TB patients had a baseline visit before treatment (month 0) and visits at month 2 and 6 (or at the end of TB treatment). Smear microscopy, and culture for Mycobacterium tuberculosis (MTB) were performed at TB diagnosis and during follow-up. Complete blood counts were measured at baseline. Treatment outcome was defined as either unfavorable (death, treatment failure or TB recurrence) or favorable (cure or treatment completion). We performed multivariable logistic regression, with propensity score regression adjustment, to estimate the association between neutrophil count with MTB culture result at month 2 and unfavorable treatment outcome. We used a propensity score adjustment instead of a fully adjusted regression model due to the relatively low number of outcomes.ResultsAmong 682 patients who had MTB culture results at month 2, 40 (5.9%) had a positive result. After regression with propensity score adjustment, no significant association between baseline neutrophil count (103/mm3) and positive MTB culture at month 2 was found among either HIV-seronegative (OR = 1.06, 95% CI = [0.95;1.19] or HIV-seropositive patients (OR = 0.77, 95% CI = [0.51; 1.20]). Of 691 TB patients followed up for at least 18 months and up to 24 months, 635 (91.9%) were either cured or completed treatment, and 56 (8.1%) had an unfavorable treatment outcome. A multivariable regression with propensity score adjustment found an association between higher neutrophil count (103/mm3) at baseline and unfavorable outcome among HIV-seronegative patients [OR= 1.17 (95% CI= [1.06;1.30]). In addition, adjusted Cox regression found that higher baseline neutrophil count (103/mm3) was associated with unfavorable treatment outcomes overall and among HIV-seronegative patients (HR= 1.16 (95% CI = [1.05;1.27]).ConclusionIncreased neutrophil count prior to anti-TB treatment initiation was associated with unfavorable treatment outcomes, particularly among HIV-seronegative patients. Further prospective studies evaluating neutrophil count in response to drug treatment and association with TB treatment outcomes are warranted.

Differentiating between active and latent tuberculosis with chest computed tomography

PurposeThe purpose of this study was to evaluate the capabilities of chest computed tomography (CT) in distinguishing between active and latent tuberculosis in patients positive for interferon-gamma release assay (IGRA) testing, and to compare the performance of CT with that of quantitative IGRA testing in a low incidence setting. Materials and methodsPatients with latent or active tuberculosis define by an IGRA positive test were retrospectively recruited. Sensitivity, specificity and accuracy were determined for CT variables and quantitative IGRA results. Final diagnosis of active tuberculosis was based on clinical data and microbiological culture. Univariable and multivariable analyses were performed using logistic regression model to identify CT variables associated with the diagnosis of active tuberculosis. ResultsA total of 92 patients with positive IGRA results who underwent CT examination were included. There were 54 men and 38 women with a mean age of 53.5±18 (SD) years (range: 40–68 years). Of them, 22 patients (24%) had positive Mycobacterium tuberculosis culture and 70 (76%) had latent tuberculosis. Among CT variables, consolidation had the greatest sensitivity (77%; 95%CI: 60–95%) and “tree-in-bud” the greatest specificity (97%; 95% CI: 93–100%) for the diagnosis of active tuberculosis. At univariable analysis “tree-in-bud”, splenic calcification and non-calcified lung nodules were the significant variables independently associated with active tuberculosis. At multivariable analysis, the adjusted odds ratio of “tree-in-bud” was 42.91 (95% CI: 5.62–327.42). Using an optimal threshold of 51 spots, quantitative IGRA yielded 64% sensitivity (95% CI: 44–84%) and 61% specificity (95% CI: 50–73%) for the diagnosis of active tuberculosis. ConclusionsIn a low incidence setting, chest CT, especially when “tree-in-bud” pattern is present, is superior to quantitative IGRA testing to identify patients with active tuberculosis among those with positive IGRA testing.