Incidence of Nosocomial Blood Stream Infection (BSI) in Intensive Care Units (ICUs) in Cairo and Beni-Suef University Hospitals

Background: Nosocomial infections (NCIs) are more frequently encountered in ICUs than in other hospital areas and represent a major socioeconomic burden. Aim of the Work: The current study aimed to evaluate the rate of nosocomial blood stream infections (BSIs) in both the adult and neonatal ICUs, the causative microorganisms, antimicrobial resistance, outcome of infection, risk factors, and to identify the most common isolates with molecular detection of the resistance gene. Methods: One thousand and ninety one patients (adults & neonates) admitted to the ICUs during the one year study period (March 2011 till February 2012) were monitored daily and those who were suspected to develop nosocomial BSIs, according to the criteria stated by the CDC, were selected for enrollment in the present study. Blood cultures were done and positive blood culture samples were subjected to colony identification to detect the causative organisms and antibiotic susceptibility testing for isolates. Detection of extended spectrum beta – lactamase producers (ESBLs) was conducted among Gram negative isolates by a screening test and confirmed by double-disc synergy test (DDST). Coagulase negative staphylococci (CoNS) isolates were tested by PCR for detection of mecA gene as they were the most common isolates in all ICUs. Two hundred and fifty intravenous catheters (IVCs) were collected and cultured by the standard quantitative catheter segment method to detect primary BSIs. Results: Out of the 1091 patients 117 had nosocomial BSIs. The rate of nosocomial BSI was 10.7% with the highest percentage in the NICU (29.9%), followed by the adult ICU of BeniSuef University Hospital (10.6%) and the lowest rate was recorded in the adult ICU of Cairo University Hospital (5.8%). Out of those positive cases, 46 patients died representing a crude mortality rate of 39% (highest mortality rates were observed with CoNS infections). Analysis of the isolated organisms showed that Gram positive organisms were reported in 84 isolates (62.2%); CoNS was the most prevalent (37%) followed by S. aureus (12.6%). Gram negativebacilli were reported in 46 isolates (34.1%), where K. pneumoniae was the most common (12.6%) followed by Acinetobacterbaumannii (11.1%). Candida albicanswas reported in only 5 isolates (3.7%). Concerning antibiotic susceptibility, Gram positive isolates were mostly sensitive to vancomycin (95%), while Gram negative isolates were mostly sensitive to levofloxacin (63%). CoNS, the most common strain in different ICUs (n=50), were tested for production of mecA gene by antibiotic susceptibility and PCR. PCR results indicated that 66 % (33/50) were mecA gene producers while 96% (48/50) were cefoxitin resistant and resistant to other B-lactam antibiotics by susceptibility testing. Regarding the 250 IVCs cultured, 20 (8%) were culture positive and coincided with results of blood cultures. The highest number of isolates was reported from the NICU and CoNS was the most common isolate (80%). These cases represent BSI with a primary site at the vascular access catheter insertion point. Conclusion: Nosocomial BSIs represent a major problem in ICUs. BSI with multi-drug resistant pathogens (especially CoNS) is difficult to treat and associated with increased mortality. Of all available antimicrobial agents, vancomycin is the most active and reliable treatment option, however over-use may lead to emergence of resistance. Therefore, restricting the use of vancomycin, along with implementation of infection control programs are the most effective means for controlling and decreasing BSIs and spread of CoNS. [Amal Balbaa, Azza Abdulazim, Mahmoud Ali, Nadia Madany and Doaa Mabrouk. Incidence of Nosocomial Blood Stream Infection (BSI) in Intensive Care Units (ICUs) in Cairo and Beni-Suef University Hospitals. J Am Sci 2013;9(11):88-99]. (ISSN: 1545-1003). http://www.jofamericanscience. org. 14