Disease and symptoms: Acinetobacter are rarely implicated as a cause of disease in healthy individuals. For this reason, Acinetobacter isolated from clinical specimens was largely ignored until the 1970s when diseases caused by Acinetobacter became increasing recognised (Joly-Guillou 2005). A. baumannii has relatively low virulence compared with other nosocomial pathogens, such as MRSA, and are largely restricted to severely ill patients in critical care environments. In these environments, A. baumannii can cause pneumonia, tracheobronchitis, bloodstream infections, urinary tract infections, cathether-related infections and rarely wound infections (Joly-Guillou 2005). Although the infections caused by A. baumannii are typically “low-grade”, due to the severely ill nature of the patient affected, crude mortality is high typically ranging from 20-60% and attributable mortality is approximately 10-20% (Joly-Guillou 2005; Falagas and Rafailidis 2007).
Treatment and antibiotic resistance: A. baumannii has progressively acquired resistance to many antibiotics. Consequently the carbapenems have become the therapy of choice for serious A. baumannii infection (Joly-Guillou 2005). However, carbapenem-resistance has emerged (conferred by transferable resistance genes such as OXA-23 and -23, VIM, IMP and NDM-1), meaning that old antibiotics with reduced efficacy and increased side effects, such as colistin, have to be used to treat serious A. baumannii. infection (Coelho et al. 2004).
Prevention and control: Screening for colonization with A. baumannii is rarely performed so identification relies on clinically-indicated cultures. Therefore, hand-hygiene, isolation of infected or colonized patients and stringent environmental hygiene are necessary for the effective control of A. baumannii (Karageorgopoulos and Falagas 2008).
A. baumannii is shed into the environment by infected patients and can survive for extend periods on environmental surfaces (Kramer et al. 2006; Thom et al. 2011). Outbreak reports highlight the importance of environmental decontamination in the control of A. baumannii (Catalano et al. 1999; Denton et al. 2004). Admission to a room previously occupied by a patient with A. baumannii increased the chances of A. baumannii acquisition (Nseir et al. 2011). Bioquell hydrogen peroxide vapour (HPV) is effective against A. baumannii in vitro (Otter and French 2009)and is more effective than bleach disinfection for the decontamination of A. baumannii on hospital surfaces (Manian et al. 2011). There is evidence that HPV can be useful for controlling the spread of A. baumannii and other Gram-negative bacteria during outbreaks and in endemic settings (Donegan et al. 2010; Manian et al. 2010; Otter et al. 2010; Gopinath et al. 2011; Kaiser et al. 2011).
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