1025. Microbial Epidemiology of Infectious Endocarditis in the Intravenous Drug Abuse Population: A Retrospective Study in East Tennessee.
Session: Poster Abstract Session: Bacteremia and Endocarditis
Friday, October 5, 2018
Room: S Poster Hall
(IE) is one of the most serious infections affecting intravenous drug users
(IVDU). IVDU have a higher incidence of IE compared to the general population.
There are a limited number of reports on the epidemiology of this infection
from the South Eastern United States. We determined the prevalence, and the
microbial epidemiology, of IE cases at our institution. We then compared this
to data from other geographical regions. This was done to help aid physicians
with choosing empiric treatment regimens, for IE, pending culture results.
Methods:A retrospective cohort
of 299 cases of IE was analyzed between January 2013 and July 2017 at a
university hospital in East Tennessee. Demographic, microbiologic, intravenous
substance use status, radiographic, and echocardiographic data were collected.
Results:Of the 299 cases, 184
(61.5%) were IVDU, and 115 cases (38.5%) were non-IVDU. IVDU and non-IVDU
positive cultures rates were similar at 87% and 86% respectively. Methicillin-Resistant
Staphylococcus aureus (MRSA) was more likely to occur in IVDU (OR 2.8,
p<0.001), and was the most common pathogen at 77 out of the 184 cases (42%).
While 23 of the 115 (20%) cases grew MRSA in the non-IVDU population.
Methicillin-Sensitive Staphylococcus aureus was the second most common
bacteria for IVDU with 36 out of 184 cases (19.6%). IVDU patients were more
likely infected with Pseudomonas aeruginosa (OR 3.384, p=0.027), which
occurred in 20 of the 184 cases (10.9%). IVDUs also experienced more right
heart involvement versus left sided involvement (OR 2.19, p=0.004).
Conclusion:S. aureus was
the most common pathogen for IE in IVDU followed by P. aeruginosa. Data
from this study solidifies that in IVDU, or if there is suspicion of intravenous
drug use, first line broad-spectrum antibiotics with excellent MRSA and P. aeruginosa
coverage is essential to empirically cover for IE. Extra attention for right
sided heart involvement should also be made on IVDU with imaging modalities.
William Lorson, DO1, Avi Das, MD1, R. Eric Heidel, PhD2 and Mahmoud Shorman, MD, FIDSA1, (1)Department of Medicine, The University of Tennessee Graduate School of Medicine, Knoxville, TN, (2)Department of Surgery, The University of Tennessee Graduate School of Medicine, Knoxville, TN