ICU-Associated Acinetobacter baumannii Colonisation/ Infection in a High HIV-Prevalence Resource-Poor Setting Ntobeko B. A. Ntusi 1 , Motasim Badri 2 , Hoosain Khalfey 2,3 , Andrew Whitelaw 4 , Stephen Oliver 4 , Jenna Piercy 3 , Richard Raine 3 , Ivan Joubert 3 , Keertan Dheda 2,3 * ¤ 1 The Cardiac Clinic, Department of Medicine, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa, 2 Lung Infection and Immunity Unit, Division of Pulmonology & Clinical Immunology, Department of Medicine, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa, 3 Department of Critical Care, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa, 4 Department of Microbiology and National Health Laboratory Service, Groote Schuur Hospital and University of Cape Town, Cape Town, South Africa Abstract Background: There are hardly any data about the incidence, risk factors and outcomes of ICU-associated A.baumannii colonisation/infection in HIV-infected and uninfected persons from resource-poor settings like Africa. Methods: We reviewed the case records of patients with A.baumannii colonisation/infection admitted into the adult respiratory and surgical ICUs in Cape Town, South Africa, from January 1 to December 31 2008. In contrast to colonisation, infection was defined as isolation of A.baumannii from any biological site in conjunction with a compatible clinical picture warranting treatment with antibiotics effective against A.baumannii. Results: The incidence of A.baumannii colonisation/infection in 268 patients was 15 per 100 person-years, with an in-ICU mortality of 26.5 per 100 person-years. The average length of stay in ICU was 15 days (range 1–150). A.baumannii was most commonly isolated from the respiratory tract followed by the bloodstream. Independent predictors of mortality included older age (p = 0.02), low CD4 count if HIV-infected (p = 0.038), surgical intervention (p = 0.047), co-morbid Gram-negative sepsis (p = 0.01), high APACHE-II score (p = 0.001), multi-organ dysfunction syndrome (p = 0.012), and a positive blood culture for A.baumannii (p = 0.017). Of 21 A.baumannii colonised/infected HIV-positive persons those with clinical AIDS (CD4,200 cells/mm 3 ) had significantly higher in-ICU mortality and were more likely to have a positive blood culture. Conclusion In this resource-poor setting A.baumannii infection in critically ill patients is common and associated with high mortality. HIV co-infected patients with advanced immunosuppression are at higher risk of death. Citation: Ntusi NBA, Badri M, Khalfey H, Whitelaw A, Oliver S, et al. (2012) ICU-Associated Acinetobacter baumannii Colonisation/Infection in a High HIV- Prevalence Resource-Poor Setting. PLoS ONE 7(12): e52452. doi:10.1371/journal.pone.0052452 Editor: D. William Cameron, University of Ottawa, Canada Received June 26, 2012; Accepted November 14, 2012; Published December 27, 2012 Copyright: ß 2012 Ntusi et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: NN receives funding from the SA MRC (South African Medical Research Council) and the Discovery Academic Foundation. KD is supported by the SA DST (Deptartment of Science and Technology) (SARChI), SA MRC, EU (FP7) and the EDCTP (European-Developing Countries Clinical Trial Partnership). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: keertan.dheda@uct.ac.za ¤ Current address: Groote Schuur Hospital, Observatory, Cape Town, South Africa Introduction Traditionally, Acinetobacter baumannii has been considered to be an opportunistic pathogen of low pathogenicity [1], but the emergence of serious community-acquired A.baumannii infection has demonstrated that this organism can be highly virulent with a propensity to cause invasive disease in non-critically ill patients. [2] Nosocomial transmission is responsible for the vast majority of A.baumannii infections, [3] and is related both to the ability of the organism to survive in the environment and the organism’s resistance to the major groups of antibiotics, resulting in a selective advantage in settings such as ICUs, where broad-spectrum antibiotic use is commonplace. The incidence of nosocomial infections due to Gram negative infections in South Africa has previously been reported to be between 24 and 36%. [4,5] When A.baumannii is isolated from patient-derived biological samples distinction is often made between colonisation and active infection (associated features of sepsis and/or a positive blood culture). [6] Globally, there has been a general trend of increasing incidence of infection due to A.baumannii. [7] For instance, in France nosocomial infection due to A.baumannii was rare in the 1970s and had increased to a prevalence of 9% by 2005. [8] Similarly, in North America, the prevalence of nosocomial infection due to A.baumannii increased from 4% in 1986 to 7% in 2003. [9] Patients at risk are often critically ill with multiple co-morbidities, concurrent infections, and on prolonged courses of antibiotics, often making it difficult to distinguish between colonisation and infection. [10] Moreover, colonisation is a risk factor for sub- sequent infection [6]. Rational planning of health care policy and interventional measures are required to tackle ICU-associated A.baumannii infection in resource-poor settings. However, there are inadequate data on which to plan interventional strategies and base recommendations. Firstly, the frequency, risk factors and associ- ated mortality of A.baumannii in African ICUs have not been PLOS ONE | www.plosone.org 1 December 2012 | Volume 7 | Issue 12 | e52452