Effects of Short- vs Prolonged-Course Antimicrobial Therapy in Patients With Uncomplicated Pseudomonal Bloodstream Infections

Human blood cells, computer illustration.
Investigators conducted a study that compared the effects of short- vs prolonged-course antimicrobial therapy on 30-day mortality outcomes and the risk for recurrent infection in patients with pseudomonal bloodstream infections.

The following article is a part of conference coverage from the IDWeek 2021, being held virtually from September 29 to October 3, 2021. The team at Infectious Disease Advisor will be reporting on the latest news and research conducted by leading experts in the field. Check back for more from the IDWeek 2021.

Short-course antimicrobial therapy may be as effective as prolonged-course therapy for the treatment of patients with uncomplicated bloodstream infections (BSI) caused by Pseudomonas aeruginosa, according to research presented at IDWeek, held virtually from September 29 to October 3, 2021.

Between May 2016 and September 2020, investigators evaluated patients with uncomplicated pseudomonal BSI at a tertiary care hospital to compare the rate of recurrent BSI and 30-day mortality between those treated with short- (7-11 days) vs prolonged-course (12-21 days) antimicrobial therapy. To compare the 2 treatment regimens, the investigators performed a propensity score analysis with the inverse probability of treatment weighting (IPTW) method.

Among a total of 1477 patients evaluated, 290 met the inclusion criteria, 97 (33%) underwent short-course therapy, and 193 (67%) underwent prolonged-course therapy. In regard to the risk for recurrent BSI and 30-day mortality, the investigators found no significant differences between patients in the prolonged-therapy vs short-course therapy (n=10 vs n=32) groups (11% vs  16%; IPTW-adjusted hazard ratio (HR), 0.61; 95% CI, 0.30−1.24; P =.17).

Compared with patients who received short-course therapy (n=10), the investigators observed that those who received prolonged-therapy (n=38) had a significantly increased risk for recurrent pseudomonalBSI within 180 days of treatment completion (10% vs 20%; IPTW-adjusted HR, 0.48; 95%CI, 0.24-0.96; P =.04). In addition, the resistant acquisition in subsequent P aeruginosa isolates was found to occur with increased frequency among patients in the prolonged-course therapy group vs those in the short-course therapy group, though the different was not statistically significant (20% vs 32%; P =.70).

These finds suggest that “short-course antimicrobial therapy could be as effective as prolonged-course therapy for uncomplicated [pseudomonal]bloodstream infections,” the investigators concluded.


Moonsuk B, Yun-Seo J, Seongman B. Short- versus prolonged-courses of antimicrobial therapy for patients with uncomplicated Pseudomonas aeruginosa bloodstream infection. Presented at: IDWeek; September 29 to October 3, 2021. Poster 519.

Visit Infectious Disease Advisor’s conference section for coverage of IDWeek 2021.