[Emerging Acinetobacter baumannii infections and factors favouring their occurrence]

Abstract

During the last decade, Acinetobacter baumannii (AB) has been increasingly responsible for infections occurring in three particular contexts (in terms of patients and environment). Community AB pneumonia is severe infections, mainly described around the Indian Ocean, and which mainly concern patients with major co-morbidities. AB is also responsible for infections occurring among soldiers wounded in action during operations conducted in Iraq or Afghanistan. Lastly, this bacterium is responsible for infections occurring among casualties from natural disasters like earthquakes and tsunamis. Those infections are often due to multidrug-resistant strains, which can be implicated in nosocomial outbreaks when patients are hospitalized in a local casualty department or during their repatriation thereafter. The source of the contaminations which lead to AB infections following injuries (warfare or natural disasters) is still poorly known. Three hypotheses are usually considered: a contamination of wounds with environmental bacteria, a wound contamination from a previous cutaneous or oropharyngeal endogenous reservoir, or hospital acquisition. The implication of telluric or agricultural primary reservoirs in human AB infections is a common hypothesis which remains to be demonstrated by further specifically designed studies.