In parallel to the ongoing national opioid crisis, the incidence rate of infective endocarditis (IE) cases has increased markedly among people aged 18 to 29 years with hepatitis C virus (HCV) infection and among people with opioid use disorder (OUD), according to study results published in Clinical Infectious Diseases.
Because IE is associated with injection drug use, researchers conducted a retrospective cohort analysis of commercial and Medicaid health insurance databases to estimate the incidence of IE cases in the United States in 2017 stratified by HIV, HCV, and OUD. The commercial database included diagnosis and procedure codes for 26 million people enrolled in approximately 350 employer-sponsored commercial health insurance plans in all 50 states.
Among those with commercial insurance, researchers estimated annual percentage changes in IE from 2007 to 2017. The Medicaid databases included 13 million enrollees from 10 to 12 states, representing 20% of Medicaid enrollees in the United States in 2017. However, researchers were unable to estimate a temporal trend in IE from 2007 to 2017 among persons with Medicaid insurance because the 10 to 12 states included in the Medicaid database were not identified and might vary from year to year.
A new incident case of IE was defined as one diagnosed at least 90 days since a prior hospitalization for IE. For both the commercial and Medicaid databases, researchers estimated the number of cases and incidence rate of IE stratified by sex, age (restricted to people aged 18-64 years), race/ethnicity, US geographic region, urban or rural location, HIV and HCV infection status, history of OUD, and history of other substance use disorder.
The weighted incidence rate of IE was 13.8 cases per 100,000 persons among persons with commercial insurance, and an unweighted incidence rate of 78.7cases per 100,000 persons among those with Medicaid.
The incidence rate of IE among commercially insured persons increased slightly from 2007 to 2017 with 13.1 cases per 100,000 persons in 2007 and 13.8 cases per 100,000 persons in 2017, with an estimated annual percentage change of 1.0% (95% CI, 0.8%-1.1%). Although the rate of IE among persons aged 50 to 59 years and 60 to 64 years decreased, it was significantly increased in persons aged 18 to 29 years with 3.7 cases per 100,000 persons in 2007 and 6.4 cases per 100,000 persons in 2017 with an estimated annual percentage change of 6.6% (95% CI, 6.1%-7.1%). In addition, this change was larger for men compared with women and for people living in rural locations vs urban locations.
While the incidence rate decreased in people with HIV, the rate increased in those HCV and those with OUD, with the largest increase seen in persons aged 18 to 29 years.
- Among persons aged 18-29 years with HCV infection, IE increased from 337.6 in 2007 to 1028.7 in 2017 (estimated annual percentage change, 15.3%; 95% CI, 13.5%-17.2%).
- Among persons aged 18-29 years with OUD, IE increased from 156.4 in 2007 to 642.9 in 2017 (estimated annual percentage change, 13.8%; 95% CI, 12.6%-15.1%).
Compared with individuals with neither HIV nor HCV infection, the adjusted risk ratio (RR) for IE was 5.70 (95% CI, 5.32-6.10) among commercially insured people with HCV infection and 7.25 (95% CI, 6.76-7.79) among Medicaid-insured persons with HCV infection. Compared with people with no substance use disorder, the adjusted RR for IE was 22.86 (95% CI, 21.73-24.04) among commercially insured people with OUD and 13.80 (95% CI, 12.84-14.83) among Medicaid-insured individuals with OUD.
Findings from this study mirrored the growing opioid crisis in the United States and “underscore[d] the importance of harm reduction strategies such as [syringe services programs] to prevent HIV and HCV transmission and to prevent IE among [people who inject drugs], as well as [medications for opioid use disorder] to prevent overdose and death and the risk of infections,” concluded the researchers.
Wong CY, Zhu W, Aurigemma GP, et al. Infective endocarditis among persons aged 18-64 years with HIV, hepatitis C infection, or opioid use disorder – United States, 2007-2017 [published online April 9, 2020]. Clin Infect Dis. doi:10.1093/cid/ciaa372