Nocardia bacteremia: a single-center retrospective review and a systematic review of the literature

Abstract Objectives Nocardia bacteremia is a rare but severe disease associated with high mortality. This systematic review is the largest and most comprehensive review performed over the past 20 years. Methods A single-center retrospective review ofNocardia bacteremia was performed using hospital microbiology records from January 1st 2010 to December 31st 2017. A systematic literature review was also performed to identify cases of Nocardia bacteremia described in the NCBI PubMed database in English between January 1st 1999 and December 31st 2018. Results Four new cases ofNocardia bacteremia are described; and systematic review identified 134 cases with sufficient information available for analysis. Of the 138 cases, median age was 58 years [interquartile range 44-69] and 70% were male. Eighty-one percent were immunocompromised (corticosteroid use (49%), hematological malignancy (20%), SOT (20%), SOM (19%) and HSCT (15%)) and 29% had endovascular devices. Pulmonary infection was the most common concurrent site of clinical disease (67%). Median incubation time to detection of Nocardia bacteremia was 4 days [IQR 3-6]. Blood cultures were the only positive microbiological specimen in 38% of cases. Median total duration of treatment was 75 days [IQR 25-182]. 30-day all-cause mortality was 28% and overall all-cause mortality 40%. Conclusions Nocardia bacteremia is most frequently identified in immunocompromised patients and those with intravascular devices. Although rare, it represents a serious infection with high associated overall mortality.