Assessing the Utility of GeneXpert MTB/Rif Assay in a Tertiary Care Centre in Southern India with Established Microscopy and Liquid Culture Facilities.

BACKGROUND: To evaluate the diagnostic accuracy of the Xpert MTB/RIF assay for the detection of M. tuberculosis in pulmonary and extra pulmonary specimens and to compare it with conventional techniques. METHODS: A prospective study was conducted with the introduction of GeneXpert in a tertiary care hospital which relied on microscopy and culture for diagnosis of tuberculosis. All patients for whom geneXpert was ordered by the physician were included in the study. Samples which did not have accompanying microscopy or MGIT culture requests were excluded from the analysis of the results. Sensitivity and specificity of GeneXpert was calculated using liquid culture as the reference test. RESULTS: Xpert MTB/RIF assay was performed on 742 samples of which 116 were positive for Mycobacterium tuberculosis. Rifampicin resistance was seen in 6 samples. The pulmonary samples showed a positivity rate of 16.8% while 17.1% of the extrapulmonary samples were positive by GeneXpert. A comparative analysis of microscopy, liquid culture and GeneXpert could be done for 88 samples. Of the 88 geneXpert positive samples, 42 were positive by smear microscopy and MGIT culture while 46 showed discordant results. Of these, 18 samples were positive by geneXpert but showed no growth in MGIT culture. 15 of these patients had undergone anti-tuberculous treatment (ATT) within the past 12 months. The sensitivity of geneXpert was 89.7% and specificity was 95.1% when compared to liquid culture as a gold standard. Sensitivity for extrapulmonary samples was 85.7% and specificity was 98.05%. CONCLUSION: To conclude, though GeneXpert detects tuberculosis within the shortest possible time, it still suffers from intermediate level sensitivity, which makes culture facilities relevant even in settings that offer an Xpert/Rif assay.

Phenotypic & molecular characterization of AmpC ß-lactamases among Escherichia coli, Klebsiella spp. & Enterobacter spp. from five Indian Medical Centers.

BACKGROUND & OBJECTIVES: AmpC ß-lactamases which are often plasmid mediated hydrolyze all ß-lactam antibiotics except cefepime and carbapenems. We evaluated the presence of AmpC ß-lactamases among Enterobacteriaceae strains recovered prospectively from patients at five Indian tertiary care centres. METHODS: The study included 909 consecutive Gram-negative isolates recovered from clinically significant specimens during June 2007 - May 2008 as part of an ICMR-ESBL study. Among the study isolates, 312 were found to be cefoxitin resistant by disc diffusion test (DDT). Minimum inhibitory concentration (MIC) determination by E test was done against amikacin, levofloxacin, impinem, meropenem, ertapenem, tigecycline and piperacillin-tazobactam. Combined DDT using phenyl boronic acid as inhibitor with cefoxitin was used for phenotypic confirmation of AmpC phenotype. The common Amp C genotypes ACC, FOX, MOX, DHA, CIT and EBC were detected by multiplex PCR. RESULTS: Plasmid mediated Amp C phenotype was confirmed in 114 of the 312 (36.5%) cefoxitin resistant isolates with 255 (81.7%) showing multidrug resistance. Susceptibility to tigecycline was highest (99%) followed by imipenem, meropenem (97%), ertapenem (89%), amikacin (85%), and piperacillin-tazobactam (74.6%). Levofloxacin resistance was 82 per cent. ESBL co carriage was observed among 92 per cent of Amp C producers. Among 114 Amp C producers, 48 could be assigned a genotype, this included CIT- FOX (n = 25), EBC (n = 10), FOX (n = 4), CIT (n = 3), EBC-ACC (n = 2) and one each of DHA, EBC-DHA, FOX -DHA and FOX-EBC-DHA. INTERPRETATION & CONCLUSIONS: Overall, AmpC phenotypes were found in 12.5 per cent isolates, multidrug resistance and ESBL co-carriage among them was high suggesting plasmid mediated spread. The study results have implications in rational antimicrobial therapy and continued surveillance of mechanisms of resistance among nosocomial pathogens.

Surgical site infection rates in six cities of India: findings of the International Nosocomial Infection Control Consortium (INICC).

BACKGROUND: Surgical site infections are a threat to patient safety. However, in India, data on their rates stratified by surgical procedure are not available. METHODS: From January 2005 to December 2011, the International Nosocomial Infection Control Consortium (INICC) conducted a cohort prospective surveillance study on surgical site infections in 10 hospitals in 6 Indian cities. CDC National Healthcare Safety Network (CDC-NHSN) methods were applied and surgical procedures were classified into 11 types, according to the ninth edition of the International Classification of Diseases. RESULTS: We documented 1189 surgical site infections, associated with 28 340 surgical procedures (4.2%; 95% CI: 4.0-4.4). Surgical site infections rates were compared with INICC and CDC-NHSN reports, respectively: 4.3% for coronary bypass with chest and donor incision (4.5% vs 2.9%); 8.3% for breast surgery (1.7% vs 2.3%); 6.5% for cardiac surgery (5.6% vs 1.3%); 6.0% for exploratory abdominal surgery (4.1% vs 2.0%), among others. CONCLUSIONS: In most types of surgical procedures, surgical site infections rates were higher than those reported by the CDC-NHSN, but similar to INICC. This study is an important advancement towards the knowledge of surgical site infections epidemiology in the participating Indian hospitals that will allow us to introduce targeted interventions.

Impact of an international nosocomial infection control consortium multidimensional approach on central line-associated bloodstream infection rates in adult intensive care units in eight cities in India.

OBJECTIVE: To evaluate the impact of the International Nosocomial Infection Control Consortium (INICC) multidimensional infection control approach on central line-associated bloodstream infection (CLABSI) rates in eight cities of India. METHODS: This was a prospective, before-and-after cohort study of 35650 patients hospitalized in 16 adult intensive care units of 11 hospitals. During the baseline period, outcome surveillance of CLABSI was performed, applying the definitions of the CDC/NHSN (US Centers for Disease Control and Prevention/National Healthcare Safety Network). During the intervention, the INICC approach was implemented, which included a bundle of interventions, education, outcome surveillance, process surveillance, feedback on CLABSI rates and consequences, and performance feedback. Random effects Poisson regression was used for clustering of CLABSI rates across time periods. RESULTS: During the baseline period, 9472 central line (CL)-days and 61 CLABSIs were recorded; during the intervention period, 80898 CL-days and 404 CLABSIs were recorded. The baseline rate was 6.4 CLABSIs per 1000 CL-days, which was reduced to 3.9 CLABSIs per 1000 CL-days in the second year and maintained for 36 months of follow-up, accounting for a 53% CLABSI rate reduction (incidence rate ratio 0.47, 95% confidence interval 0.31-0.70; p=0.0001). CONCLUSIONS: Implementing the six components of the INICC approach simultaneously was associated with a significant reduction in the CLABSI rate in India, which remained stable during 36 months of follow-up.

Effectiveness of a multidimensional approach to reduce ventilator-associated pneumonia in pediatric intensive care units of 5 developing countries: International Nosocomial Infection Control Consortium findings.

BACKGROUND: Ventilator-associated pneumonia (VAP) is one of the most common health care-associated infections in pediatric intensive care units (PICUs). Practice bundles have been shown to reduce VAP rates in PICUs in developed countries; however, the impact of a multidimensional approach, including a bundle, has not been analyzed in PICUs from developing countries. METHODS: This was a before-after study to determine rates of VAP during a period of active surveillance without the implementation of the multidimensional infection control program (phase 1) to be compared with rates of VAP after implementing such a program, which included the following: bundle of infection control interventions, education, outcome surveillance, process surveillance, feedback on VAP rates, and performance feedback on infection control practices (phase 2). This study was conducted by infection control professionals applying the National Health Safety Network's definitions of health care-associated infections and the International Nosocomial Infection Control Consortium's surveillance methodology. RESULTS: During the baseline period, we recorded a total of 5,212 mechanical ventilator (MV)-days, and during implementation of the intervention bundle, we recorded 9,894 MV-days. The VAP rate was 11.7 per 1,000 MV-days during the baseline period and 8.1 per 1,000 MV-days during the intervention period (relative risk, 0.69; 95% confidence interval, 0.5-0.96; P = .02), demonstrating a 31% reduction in VAP rate. CONCLUSIONS: Our results show that implementation of the International Nosocomial Infection Control Consortium's multidimensional program was associated with a significant reduction in VAP rate in PICUs of developing countries.