# Opioid Overdose Patients in Central Missouri, United States, Have High Rates of Hepatitis C Infection and Limited Testing History

## TL;DR

Opioid overdose patients in central Missouri have high rates of hepatitis C infection, with limited prior testing, suggesting a need for universal screening.

## Contribution

This study identifies a high prevalence of undiagnosed hepatitis C among opioid overdose patients in emergency departments.

## Key findings

- 16.7% of patients had a history of positive hepatitis C virus (HCV) tests.
- Patients aged 55-64 were more likely to test positive for HCV and less likely to be untested.
- Females were more likely to have ever received an HCV test compared to males.

## Abstract

Background: Cases of newly identified hepatitis C virus (HCV) infection increased 3.8-fold between 2010 and 2017 due to increasing injection drug use. Furthermore, multiple HIV outbreaks have been attributed to injection drug use. This retrospective cohort study assessed the prevalence of and testing history for HIV and HCV among opioid overdose patients in the emergency department.

Methods: Each encounter including an opioid overdose at three emergency departments between January 2021 and May 2022 was reviewed. Emergency department note, most recent primary care note, and laboratory results from January 2000 to May 2022 were reviewed for the history of HIV and HCV testing. Fisher’s exact test was used to identify associations of HIV and HCV status with age or gender.

Results: There were 134 encounters for 120 patients. A total of 72 were male and 48 were female. A total of 48 had a history of HCV testing. A total of 54 had a history of HIV testing. A total of 20 tested positive for HCV antibodies. One tested positive for HIV. Eight had detectable HCV viral loads, six had undetectable HCV viral loads, and six had no quantitative testing. One had a detectable HIV viral load. A total of 16.7% of both males and females had a history of a positive HCV test. Females were more likely to have ever received an HCV test compared to males (p=0.013, odds ratio (OR)=.68 (confidence interval (CI): 1.293-5.836)). Patients aged 55-64 were more likely to test positive than any other age group (p=0.018, OR=3.889 (CI: 1.391-11.81)), and were the least likely to be untested (p=0.037, OR=0.1905 (CI: 0.03914-0.9334)).

Conclusion: There is a substantial burden of HCV among opioid overdose patients in central Missouri, United States, emergency departments, particularly among male patients and those aged 55-64. Universal HCV screening for individuals being observed following an overdose could detect many undiagnosed HCV infections.