Streptococcus pyogenes Bacteremia at a Large Teaching Hospital

Abstract

Objectives The aims of the study were to review Streptococcus pyogenes bacteremia (SPB) at our 570-bed teaching hospital from 2018 to 2022 and to report epidemiology, source of SPB, comorbidities, treatment, and mortality. Methods This was deemed to be an institutional review board–exempt quality improvement project of our internal medicine residency. We reviewed records of adults (≥16 years) with SPB admitted to hospital during 5-year period from 2018 to 2022. Age, gender, date and source of bacteremia, comorbidities, antimicrobial therapy, and mortality were recorded for each patient. Comparisons to data from our 2007–2016 study were performed using Fisher's exact test with 2-tailed P value. Results There were 102 episodes of SPB during the 5-year period: 64 men (62.7%) and 38 women (37.3%). Incidence was 4.39/104 hospital discharges (HD) in 2018, 6.79/104 HD in 2019, 6.67/104 HD in 2020, 6.16/104 HD in 2021 and 5.83/104 HD in 2022. Age range was 21–94 years with mean = 56.5 years. Sources of bacteremia: skin/soft tissue infection in 52/102 (51.0%), pneumonia in 15/102 (14.7%), bone/joint infection in 13/102 (12.7%), and primary infection in 8/102 (7.8%) episodes. Other sources were as follows: endometritis (3 patients), intra-abdominal infection (3 patients), mastoiditis (2 patients), endocarditis (1 patient), and miscellaneous (4 patients). Diabetes mellitus (36.2%), injection drug use (IDU) (29.8%), chronic obstructive pulmonary disease (24.5%), and chronic liver disease (23.4%) were the most common comorbidities. The mortality rate was 15.7%. All patients received appropriate/timely initial antimicrobial therapy. Conclusions SPB was more frequent in this 5-year period than during the preceding 10-year period. Skin/soft tissue infection (51.0%) and bone/joint infection (12.7%) were expected sources of SPB but pneumonia (14.7%) was an unexpectedly frequent cause. There was more episodes of bacteremia IDU-related, 29.8% in this study, than the 7.4% in our prior study (P = 0.0004). Mortality was higher (15.7%) than in our prior study (10.3%) but this difference did not achieve statistical significance (P = 0.3663). SPB is not uncommon, is frequently associated with IDU, causes pneumonia more often than expected, and has a 15.7% mortality rate.