Mycobacteremia in tuberculosis patients with HIV infection

Background: Mycobacteremia in HIV positive tuberculosis patients is associated with extra-pulmonary tuberculosis and disseminated tuberculosis. Objective: To study the occurrence of mycobacteremia among HIV-infected patients with tuberculosis (both pulmonary and extra-pulmonary forms) using radiometric BACTEC method. Methods: HIV positive patients admitted to the Government Hospital of Thoracic Medicine with a clinical diagnosis of tuberculosis were screened. HIV serology was reconfirmed using ELISA (two different tests) at Tuberculosis Research Centre. Five ml of venous blood was collected on the day of admission to the ward before start of anti-tuberculosis therapy. Results: Of the 105 patients screened, 85 were were found to be eligible for analysis. Patients were aged between 20-40 years, with a male preponderance (5:1). Pulmonary tuberculosis was the predominant form of tuberculosis (85%), while 15 % had associated extra-pulmonary involvement. Eight-four percent of the patients had CD4 counts of less than 200 cells/mm3, with 42% being below 50 cells/mm3. Four of the 85 patients were blood culture positive; three were identified as M.tuberculosis and one as Mycobacterium phlei. Conclusions: Mycobacteremia was detected in 4% of HIV positive patients with tuberculosis. All of them were immunosuppressed with CD4 counts of <50 cells/m3. More work needs to be done in India to understand the risk factors and outcome of patients with mycobacteremia

Consistency of standard laboratory strain Mycobacterium tuberculosis H37Rv with ethionamide susceptibility testing

Drug susceptibility pattern of standard Mycobacterium tuberculosis strain H37Rv showed discrepancy in minimum inhibitory concentration method for ethionamide and consistent results were obtained for the other second line drugs namely, kanamycin and ofloxacin. It is, therefore, necessary to revisit the susceptibility testing method for ethionamide for effective clinical management of patients with drug resistant tuberculosis

Stratifying low level Isoniazid resistance using additional intermediate drug concentration

AbstractIsoniazid (INH) susceptibility testing for 100 Mycobacterium tuberculosis performed by conventional minimum inhibitory concentration (MIC) method was stratified using additional drug concentrations. Introduction of additional drug concentrations did not greatly improve the discriminatory capacity, but can be used in specialized studies pertaining to cross resistance between structural analogues of INH

Optimization of the conventional minimum inhibitory concentration method for drug susceptibility testing of ethionamide

AbstractEvaluation of newer methods and optimization of existing methods for the susceptibility testing of second-line drugs, especially ethionamide, are essential when treatment of multidrug-resistant tuberculosis (MDR-TB) is warranted. The ideal method must clearly demarcate sensitive from resistant strains. Hence, optimization of the conventional minimum inhibitory concentration (MIC) method was attempted using diluted inoculum. The optimized MIC method was evaluated using 206 Mycobacterium tuberculosis strains isolated from new and previously treated tuberculosis patients and were compared with the conventional MIC method and proportion sensitivity (PST) method. The sensitivity and specificity of the optimized MIC method in comparison with the PST method was 74% and 90%. Assessment of the optimized MIC method with the conventional MIC method gave a sensitivity of and specificity of 73% and 98%. Overall agreement between the methods was found to be ⩾80%. Endowed with the ability to identify the resistant strains precisely, the optimized MIC method can be used for screening resistance to ethionamide

Effect of temperature on storage of ethionamide during susceptibility testing

Objective: Ethionamide being thermolabile in nature, effect of temperature on the drug and its stability in liquid andsolid media during susceptibility testing procedures was assessed to understand the inconsistency in DST formats.Methods: Working solution of ethionamide and Lowenstein- Jensen (LJ) media incorporated with ethionamide werepreincubated at 4°C and 37°C prior to DST methods was incubated till 4 weeks at different temperatures and utilizedfor DST in MGIT 960.Results: Degradation of ethionamide working solution was observed at 37°C after 3 weeks of incubation. Ethionamideincorporated LJ media can be stored without compromise on susceptibility up to 5 weeks. But, a week of prior incubationat 37°C has deleterious effect on the DST profile. Ethionamide was found to degrade at 37°C after different timepoints when stored as solution or as LJ media.Conclusion: Use of DST formats that provide results within 2 weeks can be recommended for ethionamide susceptibilitytesting. J Microbiol Infect Dis 2013; 3(3): 128-132Key words: Degradation; Ethionamide; LJ medium; MGIT 960; Mycobacterium tuberculosi

Participant recruitment into a community-based diabetes prevention trial in India: Learnings from the Kerala Diabetes Prevention Program.

Background: Data on participant recruitment into diabetes prevention trials are limited in low- and middle-income countries (LMICs). We aimed to provide a detailed analysis of participant recruitment into a community-based diabetes prevention trial in India. Methods: The Kerala Diabetes Prevention Program was conducted in 60 polling areas (electoral divisions) of the Neyyatinkara taluk (subdistrict) in Trivandrum district, Kerala state. Individuals (age 30-60 years) were screened with the Indian Diabetes Risk Score (IDRS) at their homes followed by an oral glucose tolerance test (OGTT) at community-based clinics. Individuals at high-risk of developing diabetes (IDRS score ≥60 and without diabetes on the OGTT) were recruited. Results: A total of 1007 participants (47.2% women) were recruited over nine months. Pilot testing, personal contact and telephone reminders from community volunteers, and gender matching of staff were effective recruitment strategies. The major recruitment challenges were: (1) during home visits, one-third of potential participants could not be contacted, as they were away for work; and (2) men participated less frequently in the OGTT screening than women (75.2% vs. 84.2%). For non-participation, lack of time (42.0%) was most commonly cited followed by 'I am already feeling healthy' (30.0%), personal reasons (24.0%) and 'no benefit to me or my family' (4.0%). An average of 17 h were spent to recruit one participant with a cost of US$23. The initial stage of screening and recruitment demanded higher time and costs. Conclusions: This study provides valuable information for future researchers planning to implement community-based diabetes prevention trials in India or other LMICs. Trial registration: Australia and New Zealand Clinical Trials Registry: ACTRN12611000262909

Revisiting the susceptibility testing of Mycobacterium tuberculosis to ethionamide in solid culture medium.

BACKGROUND & OBJECTIVES Increase in the isolation of drug resistant phenotypes of Mycobacterium tuberculosis necessitates accuracy in the testing methodology. Critical concentration defining resistance for ethionamide (ETO), needs re-evaluation in accordance with the current scenario. Thus, re-evaluation of conventional minimum inhibitory concentration (MIC) and proportion sensitivity testing (PST) methods for ETO was done to identify the ideal breakpoint concentration defining resistance. METHODS Isolates of M. tuberculosis (n=235) from new and treated patients were subjected to conventional MIC and PST methods for ETO following standard operating procedures. RESULTS With breakpoint concentration set at 114 and 156 µg/ml, an increase in specificity was observed whereas sensitivity was high with 80 µg/ml as breakpoint concentration. Errors due to false resistant and susceptible isolates were least at 80 µg/ml concentration. INTERPRETATION & CONCLUSIONS Performance parameters at 80 µg/ml breakpoint concentration indicated significant association between PST and MIC methods

Efficacy and safety of once-daily nevirapine- or efavirenz-based antiretroviral therapy in HIV-associated tuberculosis: a randomized clinical trial

Background: Nevirapine (NVP) can be safely and effectively administered once-daily but has not been assessed in human immunodeficiency virus (HIV)–infected patients with tuberculosis (TB). We studied the safety and efficacy of once-daily NVP, compared with efavirenz (EFV; standard therapy); both drugs were administered in combination with 2 nucleoside reverse-transcriptase inhibitors. Methods: An open-label, noninferiority, randomized controlled clinical trial was conducted at 3 sites in southern India. HIV-infected patients with TB were treated with a standard short-course anti-TB regimen (2EHRZ3/4RH3; [2 months of Ethambutol, Isoniazid, Rifampicin, Pyrazinamide/4 months of Isoniazid and Rifampicin] thrice weekly) and randomized to receive once-daily EFV at a dose of 600 mg or NVP at a dose of 400 mg (after 14 days of 200 mg administered once daily) with didanosine 250/400 mg and lamivudine 300 mg after 2 months. Sputum smears and mycobacterial cultures were performed every month. CD4+ cell count, viral load, and liver function test results were monitored periodically. Primary outcome was a composite of death, virological failure, default, or serious adverse event (SAE) at 24 weeks. Both intent-to-treat and per protocol analyses were done, and planned interim analyses were performed. Results: A total of 116 patients (75% [87 patients] of whom had pulmonary TB), with a mean age of 36 years, a median CD4+ cell count of 84 cells/mm3, and a median viral load of 310?000 copies/mL, were randomized. At 24 weeks, 50 of 59 patients in the EFV group and 37 of 57 patients in the NVP group had virological suppression (P = .024). There were no deaths, 1 SAE, and 5 treatment failures in the EFV arm, compared with 5 deaths, 2 SAEs, and 10 treatment failures in the NVP arm. The trial was halted by the data and safety monitoring board at the second interim analysis. Favorable TB treatment outcomes were observed in 93% of the patients in the EFV arm and 84% of the patients in the NVP arm (P = .058). Conclusions: Compared with a regimen of didanosine, lamivudine, and EFV, a regimen of once-daily didanosine, lamivudine, and NVP was inferior and was associated with more frequent virologic failure and death