Isolated native tricuspid valve endocarditis due to group A β-hemolytic Streptococcus without drug addiction

Streptococcus pyogenes Infective Endocarditis-Association With Injection Drug Use: Case Series and Review of the Literature

BACKGROUND

Streptococcus pyogenes, or Group A Streptococcus (GAS), is not considered a typical cause of infective endocarditis (IE), but has anecdotally been observed in unexpectedly high rates in people who inject drugs (PWID) at our institution.

METHODS

All cases of possible or definite GAS IE per Modified Duke Criteria in adults at an academic hospital between 11/15/2015 and 11/15/2020 were identified. Medical records were reviewed for demographics, comorbidities, treatment, and outcomes related to GAS IE. The literature on cases of GAS IE was reviewed.

RESULTS

Eighteen cases of probable (11) or definite (7) GAS IE were identified; the mean age was 38 years, and the population was predominantly female (56%) and Caucasian (67%), which is inconsistent with local population demographics. Sixteen cases were in people who inject drugs (PWID; 89%); 14 were also homeless, 6 also had HIV (33%), and 2 were also pregnant. Antibiotic regimens were variable due to polymicrobial bacteremia (39%). One patient underwent surgical valve replacement. Four patients (22%) died due to complications of infection. The literature review revealed 42 adult cases of GAS IE, only 17 of which were in PWID (24%).

CONCLUSIONS

The 16 cases of possible and definite GAS IE in PWID over a 5-year period in a single institution reported nearly doubles the number of cases in PWID from all previous reports. This suggests a potential increase in GAS IE particularly in PWID and PWH, which warrants further epidemiologic investigation.

Mitral Valve Infective Endocarditis due to Streptococcus pyogenes: A Case Report

Infective endocarditis (IE) due to group A β-hemolytic streptococcus (Streptococcus pyogenes) has rarely been reported in the literature. We herein report a Streptococcus pyogenes native mitral valve endocarditis in a young patient and a review of the literature. The patient had a native mitral valve endocarditis with vegetation; his hemodynamic stability and a short course of antibiotic treatment prevented urgent surgery on the mitral valve. He was previously treated with cefixime and azithromycin for four days and then, upon hospital admission, with vancomycin plus amoxicillin-clavulanate. After the diagnosis of IE due to Streptococcus pyogenes, treatment with gentamicin (3 mg/kg daily) and ampicillin (12 g/day) was implemented. The patient underwent weekly echocardiographic evaluations during antibiotic treatment to document the resolution of the vegetations. He was discharged to home in good clinical conditions after a four-week course of antibiotic treatment.

An Ineffective Differential Diagnosis of Infective Endocarditis and Rheumatic Heart Disease after Streptococcal Skin and Soft Tissue Infection

We herein report the case of a 68-year-old woman with a skin and soft tissue infection at her extremities. The blood culture results were positive for Streptococcus pyogenes, and we started treatment using ampicillin and clindamycin, although subsequent auscultation revealed a new-onset heart murmur. We therefore suspected rheumatic heart disease and infective endocarditis. The case met both the Jones criteria and the modified Duke criteria. Transesophageal echocardiography revealed vegetation on the aortic valve, although the pathological findings were also compatible with both rheumatic heart disease and infective endocarditis. The present findings suggest that these two diseases can coexist in some cases.