The Clinical and Molecular Characteristics of Community-Associated Bacteremia in Persons who Inject Drugs at a New York City Tertiary Care Facility During the Opioid Epidemic.

BACKGROUND

(SA) bacteremia is a morbid complication of injection drug use (IDU), yet little is known about the biological and clinical factors that drive morbidity due to these infections in persons who inject drugs (PWID).

METHODS

We reviewed all cases of community-associated bacteremia (SAB) over a 2-year period at a large tertiary care medical center in New York City. We identified 29 PWID with community-associated SAB, who were matched randomly in a 4:1 (control:case) ratio to 112 comparisons with SAB but no IDU. Whole-genome sequencing and phylogenetic analysis were performed on SAB isolates to identify genetic and molecular similarities.

RESULTS

The PWID group was younger, more unstably housed, and more frequently diagnosed with endocarditis. Genotyping results showed comparable proportions of SA sequence types (STs) between PWID and comparisons, and ST8 accounted for a plurality of infections. Phylogenetic analysis showed 2 related pairs of SA isolates, only 1 of which occurred among PWID. The highest proportion of endocarditis episodes occurred in patients with SA isolates belonging to ST5, ST7, and ST97, but we were unable to identify significant associations between complications and specific SA virulence factors.

CONCLUSIONS

Among PWID, we did not identify specific clusters of SA, which was clonally diverse. Possible explanations include nonoverlapping IDU networks and the fact that New York is a syringe-exchange state, which may reduce the risk of shared exposures to PWID demonstrate higher rates of infective endocarditis than controls and should be targeted for early multidisciplinary intervention.