scholarly journals Time to Detection of Growth for Mycobacterium tuberculosis in a Low Incidence Area

Author(s):  
Rechana Vongthilath-Moeung ◽  
Antoine Poncet ◽  
Gesuele Renzi ◽  
Jacques Schrenzel ◽  
Jean-Paul Janssens

BackgroundDiagnosis of Mycobacterium tuberculosis (MTB) infection can be confirmed by Xpert assays within hours. However, when sample size does not allow performing both culture and Xpert, or if Xpert is negative, then formal diagnosis of MTB relies on culture and time to detection of growth (TDG) becomes critical for clinical management.ObjectivesTo determine TDG in Xpert negative samples, or in samples in which Xpert could not be performed, in a low-incidence area for MTB.MethodsRetrospective analysis (2015-2020) of a database including all cultures for mycobacteria in a University Hospital covering approximately 500’000 inhabitants. Analysis was restricted to culture positive (C+) samples for MTB for which 1/Xpert was negative or could not be performed because of limited sample volume, and 2/collected from subjects treated less than 24 hours. TDG was analyzed according to microscopy, origin of sample (pulmonary or not) and presence of cavitation.ResultsAmong 837 C+ samples for MTB, 236 samples (80% of respiratory origin) from 147 patients fulfilled study criteria; 78 samples (49 patients, 33%) were acid-fast bacilli (AFB) positive. Median (IQR) TDG was 25 (17; 40) days for all samples. TDG exceeded 28 days in 43% of samples and was significantly shorter in AFB+ vs AFB- samples, and samples from cavitary vs non cavitary or extra-thoracic disease.ConclusionsIn Xpert negative samples, or samples for which Xpert could not be performed, TDG exceeded 4 weeks in 43% of samples. AFB+ and samples from cavitary lung disease had a significantly shorter TDG.

Author(s):  
Kalpana Thangavelu ◽  
Imola Jamir ◽  
Kalaiarasan Ellappan ◽  
Krishnapriya Krishnakumariamma ◽  
Pallam Gopichand ◽  
...  

Introduction: Prevalence of Extrapulmonary Tuberculosis (EPTB) due to Mycobacteriumtuberculosis and Non-Tuberculous Mycobacteria (NTM) are on the rise especially in a developing country like India. Smear Microscopy (SM) is commonly used for detection of mycobacteria. Due to the paucibacillary nature in the extrapulmonary specimens SM pose a problem in detection. Though molecular methods are increasingly used now-a-days but there are possibilities that these reactions may get inhibited due to the presence of inhibitors in the extrapulmonary specimens. Aim: To compare Mycobacterium Growth Indicator Tubes (MGIT 960) with Lowenstein Jensen (LJ) medium for the detection of mycobacteria. Materials and Methods: The current prospective study was conducted on 1879 extrapulmonary specimens collected from a tertiary care hospital during the study period from July 2018 to March 2020. Specimens were subjected to Ziehl Neelsen (ZN) staining and Auramine Phenol (AP) staining. Culture was done in both LJ media and MGIT 960 culture. Positive mycobacterial cultures were subjected to MPT64 Immunochromatographic Test (ICT). Data were analysed using the Statistical Package for Social Sciences (SPSS®) for Windows® release 21.0 (SPSS Inc., Chicago, IL, USA). Results: A total of 129 (6.9%) and 105 (5.6%) mycobacteria was isolated by MGIT 960 and by LJ culture respectively among 1879 extrapulmonary specimens. MGIT 960 identified 118 (91.5%) as Mycobacterium tuberculosis complex and 11 (8.5%) as NTM among the total mycobacteria isolated. Out of 105 mycobacteria grown by LJ culture, 95 (90.5%) and 10 (9.5%) were identified as Mycobacterium tuberculosis and NTM, respectively. The rate of contamination associated with MGIT 960 and LJ culture was 4.6% and 4.3% respectively. The Time to Detection (TTD) was found to be significantly shorter for isolation of Mycobacterium tuberculosis by MGIT 960 culture compared to LJ culture. Conclusion: In the current study, authors compared MGIT 960 with solid LJ culture for recovery of both Mycobacterium tuberculosisComplex and NTM from extrapulmonary specimens and authors found increased recovery by MGIT 960 compared to LJ culture and also shorter duration of detection for Mycobacterium tuberculosis by MGIT 960 with comparable contamination rates.


2000 ◽  
Vol 38 (3) ◽  
pp. 1227-1230 ◽  
Author(s):  
L. Heifets ◽  
T. Linder ◽  
T. Sanchez ◽  
D. Spencer ◽  
J. Brennan

Two manual liquid medium systems, the Mycobacteria Growth Indicator Tube (MGIT) and MB Redox tube systems, were evaluated in comparison to the radiometric BACTEC-460 semiautomated system for recovery ofMycobacterium tuberculosis from sputum specimens. The highest level of recovery, from a total of 77 culture-positive specimens, occurred with the BACTEC-460 system (92.2%), followed by the MB Redox tube (80.5%) and the MGIT (63.6%) systems. The shortest time to detection was observed also among the cultures in BACTEC-460: a mean of 12 days to a growth index (GI) of 10 and 15 days to a GI of 500. The mean times for the other systems were 16 days for the MB Redox tube system and 17.4 days for the MGIT system. The proportion of cultures grown after more than 3 weeks of incubation was only 2.8 or 8.4% in BACTEC-460 (for a GI of 10 or 500) but 17.7% in MB Redox and 22.5% in MGIT. Despite these differences in comparison to the BACTEC-460 system and some differences between the MGIT and MB Redox tube systems, either of the two manual liquid medium systems presents a reasonable alternative to the BACTEC-460 system, especially for laboratories with a limited workload, and a valuable element in the laboratory protocol, in conjunction with solid media, for obtaining rapid detection of growth from about 80% of culture-positive specimens and for better overall recovery of M. tuberculosis.


2019 ◽  
Vol 3 (s1) ◽  
pp. 38-38
Author(s):  
Safa Kaleem ◽  
Christa B. Swisher

OBJECTIVES/SPECIFIC AIMS: 1. Determine positive predictive value, negative predictive value, sensitivity, and specificity of Neuro ICU nurse interpretation of real-time bedside qEEG. 2. Determine difference in time to detection of first seizure between Neuro ICU nurse qEEG interpretation and EEG fellow reads of cEEG. 3. Determine what qualities of seizures make detection by neuro ICU nurses more or less likely – e.g. duration of seizures, type of seizures, spatial extent of seizures. METHODS/STUDY POPULATION: Recruit neuro ICU nurses taking care of 150 patients admitted to the Neuro ICU at Duke University Hospital who are initiated on cEEG monitoring. Nurses will be consented for their participation in the study. Neuro ICU nurses will evaluate the qEE RESULTS/ANTICIPATED RESULTS: From literature estimates of a 20% seizure prevalence in critical care settings, we hope to have 30 patients with seizures and 120 without. Based on prior study in the Duke Neuro ICU, we hypothesize that Neuro ICU nurses will have sensitivity and DISCUSSION/SIGNIFICANCE OF IMPACT: This is the first prospective study of neuro ICU nurse interpretation of real-time bedside qEEG in patients with unknown NCSE/NCS presence. If nurse sensitivity, specificity, and positive predictive value are clinically useful, which we deem would be so at a sensitivity of 70% or greater, with acceptable false alarm rate, nurse readings of qEEG could significantly decrease the time to treatment of seizures in the Neuro ICU patient population, and perhaps could improve patient outcomes.


2010 ◽  
Vol 5 (1) ◽  
pp. 13-20
Author(s):  
S Acharya ◽  
P Ghimire ◽  
DK Khadka ◽  
S Nepali

Background: Tuberculosis (TB) is among the most serious infectious cause of global morbidity and mortality. Emergence of Multi-drug resistant tuberculosis (MDR-TB) is posing an increased threat to TB control programs. Drug susceptibility testing (DST) of Mycobacterium tuberculosis (M. tuberculosis) isolates is important for tackling such problems. Setting: National Tuberculosis Centre (NTC), Thimi, Bhaktapur, Nepal. Objectives: Comparative evaluation of two in vitro DST methods in determining susceptibility of M. tuberculosis isolates from patients attending NTC, to front-line anti-TB drugs: (Isoniazid-INH, Rifampicin-RFP, Streptomycin-SM, and Ethambutol-EMB). Methodology: This study was conducted from Sep 2006-Jun 2007. A total of 862 sputum samples (diagnosis or follow up cases) collected from patients (type of patients or their categories was not differentiated in this study) attending NTC bacteriology lab for sputum direct smear microscopy were analyzed using fluorescence microscopy. All smear positive samples, smear negative samples requested for culture were cultured. All culture positive samples confirmed as M. tuberculosis by biochemical tests were processed for DST by both proportion (PR) and resistance ratio (RR) methods. Results: Out of 862 sputum samples analyzed, 226 (26.2%) samples were positive for Acid Fast Bacilli (AFB) by fluorescence microscopy. Among 323 samples 226 smear positive samples and 97 smear negative samples requested for culture), 221 (68.4%) were culture positive, 92 (28.5%) were culture negative and 10 (3.1%) were contaminated. Out of 221 isolates of M. tuberculosis, 57.5% were resistant to one or more drugs by the PR method and 56.6% by the RR method. Similarly, MDR isolates were 29.9% and 29% by PR and RR methods respectively. On correlation analysis using Mc Nemar Chi-square test, no significant difference between the two tests were observed (p>0.05). The results showed high agreement between both methods and agreement rates to INH, RFP, SM and EMB were 93.2%, 93.7%, 93.2% and 94.1% respectively. Similarly, the agreement rates between both methods using kappa analysis showed kappa (k) value of 0.86, 0.85, 0.86 and 0.84 for INH, RFP, SM and EMB respectively, which is believed to be good agreement between both methods (k=0.80 to 1.00: Very good agreement). Conclusion: In conclusion, this study showed that both the Proportion and Resistance ratio methods are equally good for determining drug susceptibility of M. tuberculosis. Keywords: Mycobacterium tuberculosis; Drug Susceptibility Testing; Proportion Method; Resistance Ratio Method. DOI: 10.3126/saarctb.v5i1.3078 SAARC J. Tuber. Lung Dis. HIV/AIDS 2008 Vol.5(1) 13-20


2019 ◽  
Vol 19 (1) ◽  
pp. 38-44
Author(s):  
M Mikolajcikova ◽  
V Ferencikova ◽  
K Fiolkova ◽  
V Sokolikova ◽  
Z Matuskova ◽  
...  

Abstract Introduction: Voice disorders primarily affect workers in professions with increased voice demands, such as teaching personnel in educational system, singers, lecturers, actors or managers. Severe voice disorders often require a permanent change of work position. Methods: Retrospective analysis of a set of patients with occupational voice disorders who were hospitalized at the Clinic of Occupational Medicine and Toxicology, Martin University Hospital (COMaT, MUH) in the years of 2000–2017. Comparison of the data obtained with the National Centre of Medical Information (NCMI) data on the occurrence of occupational voice disorders throughout the Slovak Republic (SR). Comparison with the retrospective analysis of reported occupational voice disorders in the years of 1967-1996. Case report of a patient with an occupational voice disorder. Results: We point to a long-term low incidence of occupational voice disorders. In the years of 2000-2017, 24 cases of occupational voice disorders were reported in Slovakia, of which 20 cases were reported under item 42-1 and 4 cases under item 42-2 in the List of Occupational Diseases. Through the COMaT, MUH 11 cases of occupational voice disorders were reported during these years, of which 9 cases were listed under item 42-1 and 2 cases under item 42-2. From 1967 to 1996 there were 52 occupational voice disorders reported in Slovakia, of which 45 were under item 42-1 and 7 under item 42-2. Conclusions: As there is a tendency to underestimate the voice difficulties among teaching staff, it is necessary to provide better information about the possible consequences, prevention, and treatment of these diseases. All of this should be in the competency of occupational health services.


Author(s):  
Dipak Kumar Chattopadhyay

Introduction: Siderophore, the low molecular weight ferric iron chelator, is secreted extracellularly by Mycobacterium tuberculosis, an obligate aerobe. The pathogenic mycobacteria need iron as co-factor for the extracellularly secreted enzyme Superoxide Dismutase (SOD) for its pathogenicity as well as it requires iron for its metabolic functions like reduction of oxygen for synthesis of Adenosine Triphosphate (ATP), etc. The termination of impulse conduction is endorsed by the rapid hydrolysis of Acetylcholine (ACh) by Acetylcholinesterase (AChE) in the central as well as peripheral nervous system (cholinergic pathway). The inhibitors to Cholinesterase (ChE) might lead to accumulation of ACh, hyper stimulation of nicotinic and muscarinic receptors and also disruption of neurotransmission. Possibility of an inhibitor substance for AChE in Tuberculosis (TB) patients interestingly correlates with the symptom of night sweating in those subjects. Aim: To assay the level of serum ChE in normal control, lung disease control and tubercular subjects;circumvent the serum ChE level as a diagnostic potential in TB at an early stage. Materials and Methods: The study was conducted on total 124 subjects, and were divided into three groups: Group 1: normal control (n=31), Group 2: lung disease control (n=31) and Group 3: patients suffering from TB {3A: pulmonary TB (n=31) and 3B: extrapulmonary TB (n=31)}. Serum ChE activity for all the subjects were measured according to the method of Hestrin S. Serum ChE level was assayed for group 3 subjects after additional one month’s anti-TB drug treatment and also for group 2 subjects after one month with usual treatment. The level of significance was assessed using Student’s t-test. Results: There was a significant inhibition of serum ChE activity in both pulmonary and extrapulmonary TB patients in comparison to that of in normal control as well as lung disease control subjects (p<0.01). With the anti-tubercular drug therapy for one month, there was significant recovery in the serum ChE activity in pulmonary as well as extrapulmonary tubercular subjects (p<0.01). Conclusion: It appears that the high level of hydroxamate type of siderophores (secreted by Mycobacterium tuberculosis for acquiring iron) might form ACh ferric hydroxamate complex binding more strongly with serum ChE resulting in inhibition of serum ChE activity in tubercular subjects. With anti-tubercular drug therapy, there was decrease in serum ACh ferric hydroxamate complex level resulting in recovery of serum ChE activity.


2021 ◽  
pp. 00880-2020
Author(s):  
Salma G. Abdelhady ◽  
Eman M. Fouda ◽  
Malak A. Shaheen ◽  
Faten A. Ghazal ◽  
Ahmed M. Mostafa ◽  
...  

BackgroundChildhood interstitial and diffuse lung diseases (chILD) encompass a broad spectrum of rare pulmonary disorders. In most developing middle eastern countries, chILD is still underdiagnosed. Objective: To describe and investigate patients diagnosed with chILD in a tertiary university hospital in Egypt.MethodsWe analyzed data of consecutive subjects (<18 years) referred for further evaluation at the Children's Hospital, Ain Shams University. Diagnosis of chILD was made in accordance with the chILD-EU criteria. The following information was obtained: demographic data, clinical characteristics, chest CT findings, laboratory studies, spirometry, BAL and histopathology findings.Results22 subjects were enrolled over 24 months. Median age at diagnosis was 7 years (range 3.5–14 years). The most common manifestations were dyspnea (100%), cough (90.9%), clubbing (95.5%) and tachypnea (90.9%). Systematic evaluation led to the following diagnoses: hypersensitivity pneumonitis (n=3), idiopathic interstitial pneumonias (n=4), chILD related to chronic granulomatous disease (n=3), chILD related to small airway disease (n=3), postinfectious chILD (n=2), Langerhans cell histiocytosis (n=2), Idiopathic pulmonary hemosiderosis (n=2), granulomatous lymphocytic interstitial lung disease (n=1), systemic sclerosis (n=1), familial interstitial lung disease (n=1). Among the subjects who completed the diagnostic evaluation (n=19), treatment was changed in 13 (68.4%) subjects.ConclusionSystematic evaluation and multidisciplinary peer review of chILD patients at our tertiary hospital led to changes in management in 68% of the patients. This study also highlights the need for an Egyptian chILD network with genetic testing, as well as the value of collaborating with international groups in improving health care for children with chILD.


PEDIATRICS ◽  
1979 ◽  
Vol 63 (2) ◽  
pp. 198-203
Author(s):  
Marc O. Beem ◽  
Evelyn Saxon ◽  
Margaret A. Tipple

Infants with untreated chlamydial pneumonia shed Chlamydia trachomatis and are symptomatic for many weeks. We used sulfisoxazole, 150 mg/kg/day, or erythromycin ethyl succinate, 40 mg/kg/day, for approximately 14 days to treat 32 patients with chlamydial pneumonia of infancy, and observed them for nasopharyngeal shedding of C trachomatis and changing clinical status. All infants stopped shedding chlamydiae soon after treatment was started. After treatment, three of the 25 infants tested again became culture positive (but did not have clinical relapse). All infants improved clinically. In 24 (83%) of 29 infants, where the onset of improvement could be timed, improvement began within seven days of starting treatment. Progression to complete recovery was observed in 27 of 28 infants examined between two weeks and two months of treatment completion. Neither the existence of concomitant viral infection nor the duration of illness or hospitalization before starting treatment influenced the interval between initiation of treatment and onset of clinical improvement. While these observations do not prove, they are at least compatible with the hypotheses that C trachomatis plays a central etiologic role in this illness and that termination of chlamydial infection is beneficial clinically. Pending the availibility of data from controlled studies, we believe that either of the treatment programs outlined warrant consideration in the clinical management of patients with chlamydial pneumonia of infancy.


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