Epidemic outbreaks of multidrug-resistant (MDR) Acinetobacter baumannii (AB) in intensive care units (ICUs) are increasing. The incidence of MDR-AB bacteremia, which develops as a result of colonization, is increasing through widespread dissemination of the pathogen, and further colonization. Ji Ye Jung and colleagues in the Department of Internal Medicine at Yonsei University College of Medicine in Seoul, Republic of Korea, sought to determine risk factors for MDR-AB bacteremia in patients colonized with MDR-AB in the ICU.
The researchers conducted a retrospective, observational study of 200 patients colonized with MDR-AB in the ICU at Severance Hospital in South Korea during the outbreak period between January 2008 and December 2009.
Of the 200 patients colonized with MDR-AB, 108 developed MDR-AB bacteremia, and 92 did not, according tot eh researchers. APACHE II scores were higher in bacteremic than non-bacteremic patients at the time of ICU admission and colonization (24.0 vs. 21.6; P = 0.035, 22.9 vs. 16.8; P < 0.001, respectively). There was no difference between the two groups in the duration of time from ICU admission to colonization (7.1 vs. 7.2 days; P = 0.923), but the duration of time at risk was shorter in bacteremic patients (12.1 vs. 6.0 days; P = 0.016). A recent invasive procedure was a significant risk factor for development of bacteremia (odds ratio = 3.85; 95% CI 1.45 10.24; P = 0.007). The researchers add that multivariate analysis indicated infection and respiratory failure at the time of ICU admission, maintenance of mechanical ventilation, maintenance of endotracheal tube instead of switching to a tracheostomy, recent central venous catheter insertion, bacteremia caused by other microorganism after colonization by MDR AB, and prior antimicrobial therapy, were significant risk factors for MDR-AB bacteremia.
The researchers concluded that patients in the ICU who are colonized with MDR-AB should be considered for minimizing invasive procedures and early removal of the invasive devices to prevent development of MDR-AB bacteremia. Their works was published in BMC Infectious Diseases.
Reference: Jung JY, et al. Risk factors for multi-drug resistant Acinetobacter baumannii bacteremia in patients with colonization in the intensive care unit. BMC Infectious Diseases 2010, 10:228doi:10.1186/1471-2334-10-228.