Given the high prevalence of viral hepatitis among patients with substance use disorders, particularly people who inject drugs (PWID), it is crucial for addiction psychiatrists to understand prevention, detection, and treatment strategies. Early intervention can reduce the incidence of severe liver disease, such as advanced hepatic fibrosis/cirrhosis, liver failure, and cancer. In this article, we will provide an overview of viral hepatitis, provide practical steps to integrate hepatitis screening and monitoring into your practice, and tell you when to seek consultation from a hepatologist.

Understanding viral hepatitis
Hepatitis B (HBV) and hepatitis C (HCV) infections are major drivers of liver-related morbidity and mortality. Symptoms at the onset are typically mild, and many patients are asymptomatic, but more than half experience:

Mild flu-like symptoms 
Liver-specific symptoms (eg, right upper quadrant tenderness, dark urine, or pale stool)
Symptoms typically resolve within four to six weeks, so most patients do not know they were infected. In fact, it is estimated that only 10% of those with HBV and 20% with HCV are aware of their infection (www.tinyurl.com/587y6j5u).

Once infected, some patients clear viral hepatitis on their own, while others develop chronic infections that significantly increase the risks of cirrhosis, hepatocellular carcinoma (HCC), and liver-related death. Chronic HBV infection develops in only about 5% of infected adults, but every five years a fifth of those chronically infected will develop cirrhosis. Once cirrhosis develops, the risks of severe complications like liver failure and HCC are considerably heightened (Fattovich G et al, J Hepatol 2008;48(2):335). 

HCV, on the other hand, is much more likely to progress to chronic infection, often leading to cirrhosis and its associated complications over time (Grebely J et al, Hepatology 2014;59(1):109–120). In both HBV and HCV, the progression to cirrhosis dramatically increases the likelihood of developing HCC, underscoring the importance of early detection and management (Hu KQ, Hepatology 1999;29(4):1311–1316).

Viral hepatitis and drug use
HBV and HCV are bloodborne infections transmitted via blood and sexual contact, putting PWID at particularly elevated risk. The prevalence in this population is very high, with studies estimating that nearly 1 in 10 have HBV and more than half have HCV (Degenhardt L et al, Lancet Glob Health 2017;5(12):e1192–e1207). For those who have injected drugs for more than a decade, up to 90% have been infected with HCV (Edlin BR et al, Curr Hepat Rep 2007;6(2):60–67). 

Drug use can lead to the spread of viral hepatitis via several mechanisms:

Sharing of syringes and other drug paraphernalia (eg, spoons, filters, pipes) serves as the primary transmission source among PWID (www.tinyurl.com/bdcvm7n7). 
High-risk sexual behaviors increase the risk of contracting viral hepatitides. 
Chronic drug use may lead to higher risk of viral transmission, higher cumulative viral load, and accelerated disease progression due to drug effects on the immune system (Blackard JT and Sherman KE, Viruses 2021;13(12):2387).

Your role as a clinician

Screening 

The CDC recommends that all adults be screened for HBV and HCV at least once in their lifetime (Schillie S, MMWR Recomm Rep 2020;69(2):1–17; www.tinyurl.com/yc5wh456). However, patients with ongoing risk factors should be screened every 6–12 months, including individuals who use injectable drugs, men who have sex with men, those with sexual partners who have HBV and HCV, those who have HIV, and immunocompromised individuals. 

To screen for HBV, you should order three tests:

• HBV surface antigen (HBsAg)
• HBV surface antibody (HBsAb)
• HBV core antibody (HbcAb)

Screening for HCV is simpler, with only a single initial lab to order:

• HCV antibody (HCV Ab)
• If HCV Ab is positive, then follow up with an HCV RNA
• See the “Interpretation of HBV and HCV Serologic Markers” table below.

Prevention
Educate your patients on HBV and HCV risks associated with drug use. For example, you can say, “Drug use raises your risk of contracting hepatitis B and C, which can lead to serious liver disease down the line. While abstaining from drugs is always the safest option, there are some ways to lower the risk, even if you are not able to stop using completely right now.” Switching from injection drug use to other routes of administration can lower the risk. Whenever possible, provide patients with sterile syringes and new drug-use equipment. If you don’t have access to those yourself, resources can be located through many public health departments and the North American Syringe Exchange Network (www.nasen.org).
Additionally, HBV has an effective vaccine. Uninfected patients who are not already vaccinated should be offered the vaccine, which is available through primary care, community health centers, and many large chain pharmacies. If your patient is unsure about their vaccination status, the CDC recommends offering them the vaccine anyway (www.tinyurl.com/54f2sd54).

Treatment
Patients who screen positive for HBV or HCV should be referred to a hepatologist for further management. Telling patients what to expect, emphasizing next steps and the importance of the referral, may help improve their treatment adherence. Likewise, assess for any psychosocial barriers to treatment and, whenever possible, address them before making the specialist referral.

For patients with HBV, you can let them know that while there isn’t a definitive cure, hepatologists will closely monitor their liver health, watching for signs of advanced fibrosis, cirrhosis, or liver cancer. Some patients may qualify for treatments like interferon or antiviral therapies, which can help control the virus and reduce the risk of complications. 
For HCV, the conversation is more optimistic—thanks to ­direct-acting antiviral therapy, most patients can now achieve a cure with treatment (Simmons B et al, Clin Infect Dis 2016;62(6):683–694). Reassure your patients that a referral to a hepatologist will allow them to receive expert care tailored to their condition, whether it’s monitoring for HBV or curative therapy for HCV. If a specialist is not available, or if the patient cannot afford one, primary care or family practice doctors can prescribe care as well (Andrews RR, Am Fam Physician 2018;98(7):413–416).

Carlat Verdict: Addressing viral hepatitis in addiction care is essential to improving patient outcomes. Regular screenings, facilitating access to preventive measures like vaccinations and sterile syringes, and referral to hepatology can help prevent the severe complications of viral hepatitis, such as cirrhosis and HCC, improving both the quality of life and longevity for patients with SUDs.