Anaerobic bacteria make up a large part of the human bacterial flora by colonizing the skin and mucous membranes. However, they can also be opportunistic pathogens and cause serious infections in almost all anatomical sites [1,2]. Worldwide, the proportion of anaerobic bacteraemia is 0.5–15% [1]. In Belgium, it is 3.3%, corresponding to an incidence of 0.51/1000 hospitalized patients [3,4]. Various studies have shown a clear increase of the incidence of anaerobic bacteremia. This increase seems to have multifactorial origins, such as the aging of the population and the presence of co-morbidities [3–6].
