Decreasing Prevalence of Multidrug-Resistant Acinetobacter Baumannii in Rīga East University Hospital

Abstract

There has been an increasing tendency of infections caused by multidrug-resistant organisms (MDRO), including multidrug-resistant Acinetobacter baumannii (MDRAB), in the Rīga East University Hospital (REUH) during the last decade. Over the last two years (2014-2015), this tendency has reversed and the prevalence of MDRAB has decreased considerably. In this study we assessed the prevalence of MDRAB in intensive care units (ICUs), internal medicine, surgery units and analysed antibiotic sensitivity profiles. In addition, we determined if current infection control measures are preventing further increase of infections caused by MDRAB in REUH. Retrospective Acinetobacter baumannii prevalence data were collected for the period from 2009 until 2012. For the time period from the beginning of 2013 until 2015, after implementing such infection control measures as control of compliance to hand hygiene guidelines, a review of central venous catheter insertion protocols and regular search for sources of MDRAB in hospital environment, prospective follow-up of new cases was conducted. Antimicrobial sensitivity profiles were assessed for the period from 2013 until 2015. Data were processed with the statistical software WHONET 5.5. Bacteria identification and antibiotic susceptibility testing were performed by VITEK 2 compact, BioMerieux, France. The prevalence of MDRAB in the period 2009 to 2013 increased from 71 to 217 cases per year, but from between 2013 (time of implementing infection control measures) and 2015 it decreased to 113 cases in 2015. In the three year period (2013-2015), the proportion of MDRAB causing bloodstream infections (BSI) and central nervous system infections (CNSI) was 15.85% from all identified MDRAB cases. Of the 113 MDRAB infections diagnosed in 2015, BSI was found in 16.81% cases (n = 19). Antibiotic resistance testing showed that colistin is the most effective drug against MDRAB. The majority of Acinetobacter baumannii isolates were resistant to Ampicillin/Sulbactam, Piperacillin/Tazobactam, Ceftazidime, Cefepime, Imipenem, Meropenem, Amikacin, Gentamicin, Tobramycin, and Ciprofloxacin. Over the last two years (2014-2015), prevalence of MDRAB infections decreased considerably. In the time period from 2013 to 2014, resistance of Acinetobacter baumannii increased to imipenem, ciprofloxacin and colistin, while decreased slightly to amikacin. Rigorous infection control measures, such as identification and elimination of new MDRAB sources in environment, review of the central venous catheter insertion protocol and improvements in hand hygiene, are crucial for decreasing distribution of and invasive infections caused by MDRAB in the hospital environment.