Methicillin-resistant Staphylococcus aureus transmission in a low-prevalence healthcare setting

The aim of this study was to assess the nosocomial transmission of methicillin-resistant Staphylococcus aureus[MRSA] and the predictive role of colonization pressure [CP] in a low-prevalence healthcare setting. A retrospective analysis of MRSA infection rates from 2004 to 2009 at the Saudi Aramco Dhahran Health Center, Saudi Arabia, was performed. MRSA patient-days, susceptible patient-days, nosocomial incidence and CP were calculated for each month from January 2008 to December 2009. During the study period, 878 cases of MRSA colonization/infection were identified. Of these cases, 777 [88.4%] and 101 [11.5%] were community-acquired MRSA [CA-MRSA] and healthcare-associated MRSA [HA-MRSA] cases, respectively. A decrease in the number of HA-MRSA cases and an increase in the number of CA-MRSA cases were observed during the study period. The incidence of nosocomial infection per 1000 susceptible patient-days was 1.17 in 2008 and 0.7 in 2009. The monthly colonization pressure ranged from 0.1 to 1.62 throughout the 2-year period. Nosocomial transmission was observed in 13 months of the 24-month study period. No association between the CP of the preceding month and the incidence of nosocomial transmission in the subsequent month was observed. In a setting of low MRSA prevalence, CP does not appear to be a useful predictor of nosocomial transmission or incidence

Prevalence and antimicrobial susceptibility pattern of extended-spectrum beta-lactamase-producing enterobacteriaceae in the United Arab Emirates

To investigate the prevalence and antibiotic susceptibility pattern of extended-spectrum beta-lactamases [ESBL]-producing Enterobacteriaecae among patients in the United Arab Emirates. A total of 130 Enterobacteriaceae comprising of Escherichia coli [n = 83], Klebsiella pneumoniae [n = 45] and Klebsiella oxytoca [n = 2] was studied. Of these 130 isolates, 64 were from urine. ESBL screening was by disc diffusion and confirmatory tests for ESBL phenotype were conducted using BD Phoenix[TM] ESBL System and cephalosporin/clavulanate combination discs. Susceptibility to a panel of antibiotics was evaluated. Of the 130 isolates, 53 [41%] were identified as having ESBL phenotype; of these, 32 [60%] were E. coli, 20 [36%] K. pneumoniae and 2 [4%] K. oxytoca. ESBL phenotype was seen in 100% of endotracheal tubes isolates, 20 [31%] from urine, 7 [58%] from blood and 4 [80%] from catheter tips. Amikacin susceptibility was 100%. Over 90% of ESBL isolates showed resistance to aztreonam and cephalosporins. All Klebsiella isolates were carbapenem sensitive. One ESBL isolate showed intermediate resistance to imipenem and meropenem [both MIC 8 micro g/ml], cefotetan [MIC 32 micro g/ml] and piperacillin/ tazobactam [MIC 32 micro g/ml]. MIC for the carbapenems was lower in non-ESBL isolates [0.034 micro g/ml] than ESBL isolates [0.071 micro g/ml]. Resistance to gentamicin, ciprofloxacin and piperacillin/tazobactam was higher in ESBL than non-ESBL isolates [p < 0.05]. A high prevalence of ESBL-producing bacteria exists among in-patients in the United Arab Emirates. Amikacin and carbapenems remain the most effective drugs, but the presence of carbapenem-resistant ESBL-producing E. coli and occurrence of multidrug resistance are of concern. Continued surveillance and judicious antibiotic usage are recommended

Impact of educationl interventions on the quality of blood culture specimens

Blood cultures [BC] are among the most important specimens for detection of etiologic agents in severe infections. At Salmaniya Medical Complex [SMC], the number of BCs increased from 10580 in 2002 to 13123 for 2004. The specimens likely to be contaminated averages 4.5 percent of the total BC processed with consumption of human and financial resources. We assessed the impact of an educational intervention aimed at decreasing false positivity to internationally accepted levels [<3 percent]. During October-November 2004, BC received at the Microbiology Laboratory at SMC were examined for appropriateness. During the ensuing two investigational months [December 2004- January 2005] an educational intervention was carried out which included phone calls, personal visits in the Wards, practical and theoretical sessions with the health care workers, distribution of Guidelines and attachment of online messages to reports. In the post-intervention period [February -March 2005], the appropriateness parameters were reassessed. Fifty-nine percent of BC received was inappropriate with no significant changes before and after the educational intervention. Although we were able to decrease the number of volume-appropriate bottles likely contaminated and reduce the number of cultures likely contaminated, the figures were still above the international benchmark value. We observed an increase in the number of bottles containing less than the minimal requirement of 3ml of blood. Education per se is not effective in reducing contamination and costs. To succeed the best approach will be to rely on dedicated phlebotomists team which can be a cost effective solution saving between USD720,00 and 1.3 million annually