In recent years, clinicians have seen an uptick in viruses like HIV and hepatitis C virus (HCV) being transmitted through the sharing of needles and other drug paraphernalia. Another infectious complication of injection drug use (IDU) is IDU-related infective endocarditis (IDU-IE), a condition resulting from bacteria introduced into the vein in the process of injection.

After observing an increasing young patients being admitted to Boston-area hospitals with IDU-IE, my colleagues and I sought to determine if the prevalence of these infections seen in our region matched those throughout the country. We also wanted to determine the characteristics of patients infected with IDU-IE. Previous research indicates that rates of HCV are higher in younger populations, a finding that was also linked to an increased likelihood of transmitting the virus via injection drug use.

Assessing National Trends in IDU-IE

Published in Open Forum Infectious Diseases, our study utilized the publicly available Healthcare Cost and Utilization Project National Inpatient Sample (HCUP/NIS) database, which includes age, race, ICD-9 code, and other demographic data for inpatient discharges from community hospitals across the country. We used ICD-9 codes for endocarditis, illicit drug use, and HCV to identify cases of IDU-IE between 2000 and 2013.

Our most important finding was that the epidemiology of IDU-IE has changed in recent years, with an increasing frequency among patients younger than 34, Caucasians, and females. During the study period, the proportion of patients hospitalized for infective endocarditis whose infections were related to injection drug use increased from 7% to 12%. The proportion of hospitalizations for heart infections that were linked to drug use among patients aged 15 to 34 increased from 27% to 42%. Additionally, the proportion of such hospitalizations among Caucasian patients increased from 40% to 69%.

While the majority of IDU-IE cases were among males, females accounted for 53% of IDU-IE cases among patients aged 15 to 34. Although further research is needed to determine the causes behind the changing case composition of IDU-IE, the demographic shift appears to mirror trends that have been observed in the nationwide opioid epidemic.

Start the Discussion about IDU-IE

Our findings reinforce the importance of asking all patients with endocarditis symptoms about drug use. Injection drug users should be counseled on how to prevent IDU-related infections. These discussions should cover how the drugs are prepared, how the skin and needles should be cleaned between uses, and the importance of seeking care if an abscess or cellulitis develops in order to prevent infections from entering the bloodstream and heart valves.

Harm-reduction programs, such as opioid replacement treatment or needle exchanges, can be expensive to develop and maintain. However, recent research suggests that these programs can be cost effective by preventing complications of injection drug use among patients with HIV. Additional prospective clinical studies are needed to determine which interventions are most effective in preventing IDU-IE as well as in reducing healthcare costs through saving lives and other related complications.

Alysse Wurcel, MD, MS, has indicated to Physician’s Weekly that she has no financial interests to disclose.