What is hepatitis?
Hepatitis is an inflammation of the liver. It can be caused by a variety of toxins (such as drugs or alcohol), autoimmune conditions, or pathogens (including viruses, bacteria, or parasites) . Viral hepatitis is caused by a family of viruses labeled A, B, C, D, and E; each has its own unique route of transmission and prognosis (see table). Hepatitis B (HBV) and hepatitis C (HCV) are the most common viral hepatitis infections transmitted through the risky behaviors that drug users often engage in. Approximately 800,000–1.4 million people are living with HBV and 2.7–3.9 million people are living with HCV in the United States.
Left untreated, hepatitis can lead to cirrhosis (progressive deterioration and malfunction) of the liver and a type of liver cancer called hepatocellular carcinoma (HCC). In fact, HBV and HCV infections are the major risk factors for liver cancer worldwide―an estimated 22,000 people are expected to die from this disease in 2013 in the United States alone, a number that has been steadily increasing over the past several years and now exceeds deaths linked to human immunodeficiency virus (HIV; see figure below) . During the next 40–50 years, 1 million people with untreated chronic HCV infection will likely die from complications related to their HCV .
What is the relationship between drug use and viral hepatitis?
Drug and alcohol use places individuals at particular risk for contracting viral hepatitis. Engaging in risky sexual behavior that often accompanies drug use places individuals at risk for contracting HBV, and less frequently HCV. Injection drug users (IDUs) are at high risk for contracting HBV and HCV from shared needles and other drug preparation equipment, which exposes them to bodily fluids from other infected people. Because of the compulsive nature of addiction, IDUs repeatedly engage in these unsafe behaviors, which can make them “super-spreaders” of the virus. A recent study reported that each IDU infected with HCV is likely to infect about 20 others and that this rapid transmission of the disease occurs within the first three years of initial infection. Drug and alcohol use can also directly damage the liver, increasing risk for chronic liver disease and cancer among those infected with hepatitis. This underscores that early detection and treatment of hepatitis infections in IDUs and other drug users is paramount to protecting both the health of the individual and that of the community.
What other health challenges do IDUs with hepatitis have?
Injection drug users (IDUs) with hepatitis often suffer from several other health conditions at the same time, including mental illness and HIV/AIDS thus requiring care from multiple healthcare providers. Drug abuse treatment is critical for IDUs, as it can reduce risky behaviors that increase the chance of transmitting hepatitis. Research has shown that patients with hepatitis receiving medication-assisted therapy for their opioid addiction can be safely treated with antiviral medications . To enhance HCV care, NIDA is examining coordinated care models that utilize case managers to integrate HCV specialty care with primary care, substance abuse treatment, and mental health services so that these patients get treatment regimens that address all of their health care needs.
What treatments are available for viral hepatitis?
Medications are available for the treatment of chronic HBV and HCV infection. For chronic HBV infection, there are several antiviral drugs (adefovir dipivoxil, interferon alfa-2b, pegylated interferon alfa-2a, lamivudine, entecavir, and telbivudine). People who are chronically infected with HBV require consistent medical monitoring to ensure that the medications are keeping the virus in check and that the disease is not progressing to liver damage or cancer.
There are also antiviral medications available for HCV treatment; however, not everyone needs or can benefit from treatment. Until recently, only two antiviral medications (pegylated interferon and ribavirin) were available to treat HCV infection. Although both are effective, serious side effects including depression and suicidal thoughts are experienced by some patients. Now, there are two new safer, direct-acting antiviral (DAA) medications available (bociprevir and telaprevir), which are administered by injection with pegylated interferon. This new treatment lasts between 12-48 weeks depending on the individual and cures HCV infection, unlike treatment for HIV which lasts a lifetime and does not rid the body of HIV. Research on HCV antivirals continues, and several new promising medications that avoid the adverse events associated with pegylated interferon and can be administered orally (not injected) are in development.
Some people are able to clear the HCV virus (that is, rid it from their bodies) without medications. Recently, NIDA researchers have identified genes that are associated with spontaneous clearance of HCV. These genes also enable people who are unable to clear HCV on their own to respond more favorably to treatment medications. This new information can be used to determine which patients can benefit most from HCV treatment. More studies must be done, but this is a first step to personalized medicine for the treatment of HCV.
How do I know if I am infected with viral hepatitis?
The number of new HBV and HCV infections has been declining in recent years, but the number of people living with chronic hepatitis infections is considerable, and deaths associated with untreated, chronic hepatitis infections have been on the rise. This is because most people don’t know they are infected until the disease has begun to damage their liver, highlighting why screening for viral hepatitis is so important.
Initial screening for HBV or HCV involves antibody tests, which show whether you have been exposed to the hepatitis virus, although not necessarily whether you are still infected. A positive antibody test should then be followed up with a test that measures the amount of virus in your blood. If this follow-up test is positive, then you should seek advice from a physician that specializes in viral hepatitis treatment. Because screening for hepatitis is so critical for linking people who test positive to the care they need, NIDA is studying new rapid HCV antibody tests that can be used in drug treatment settings.
The CDC now recommends that people who use drugs be tested for hepatitis (HBV and HCV) as part of routine medical care. To determine if you are at risk for contracting hepatitis, the CDC has created an online assessment tool to help you find out.
- More about HBV testing: http://www.cdc.gov/hepatitis/B/bFAQ.htm#bFAQ23
- More about HCV testing: http://www.cdc.gov/knowmorehepatitis/Media/FactSheets.htm
- Locate a testing center near you: http://www.cdcnpin.org/scripts/search/OrgSearch.aspx
- Hardtke-Wolenski, M., et al., Genetic predisposition and environmental danger signals initiate chronic autoimmune hepatitis driven by CD4+ T cells. Hepatology, 2013.
- Rein, D.B., et al., Forecasting the morbidity and mortality associated with prevalent cases of pre-cirrhotic chronic hepatitis C in the United States. Dig Liver Dis, 2011. 43(1): p. 66-72.
- Ly, K.N., et al., The increasing burden of mortality from viral hepatitis in the United States between 1999 and 2007. Ann Intern Med, 2012. 156(4): p. 271-8.
- Magiorkinis, G., et al., Integrating phylodynamics and epidemiology to estimate transmission diversity in viral epidemics. PLoS Comput Biol, 2013. 9(1): p. e1002876.
- Bruce, R.D., et al., A review of pharmacological interactions between HIV or hepatitis C virus medications and opioid agonist therapy: implications and management for clinical practice. Expert Rev Clin Pharmacol, 2013. 6(3): p. 249-69.