Background

The hepatitis C virus is an infection usually transmitted through blood. It is a chronic infection that over time can cause liver damage that can result in death. It is estimated that over 3 million Americans have chronic hepatitis C infections, which cause between 8,000 and 10,000 deaths annually. It is predicted that this death rate will increase four-fold over the next decade, as the numbers of people infected more than 20 years ago reach the point at which serious complications of chronic liver disease, such as cirrhosis and liver cancer, are likely to develop.

Although injecting drug use is the major mode of transmission of hepatitis C, alcoholism is also common among infected persons. To a large extent this relationship may be due to the fact that the same people often abuse both alcohol and drugs. At least one study, however found that alcoholics were more likely to have hepatitis C even when other common causes, such as intravenous drug use, blood transfusions, tattoos, and other risk factors had been taken into consideration.

 

The Current Study

This study is designed to improve understanding of what factors are associated with hepatitis C infection and how the influence of these factors differed among men and women. All clients seen at the Erie County, Pennsylvania Department of Health sexually transmitted disease clinic were screened for hepatitis C and administered a brief questionnaire on alcohol and drug use and other risk factors. A sample of clients over age 18 and clients known to have hepatitis C were invited to participate in the study.

 

Study Findings

Some demographic characteristics were associated with infection:

• Clients positive for hepatitis C tended to be older than the rest of the clinic population by about 14 years.
• Unemployment was associated with infection among females but not among males.
• Rates of HCV were higher among Black males than White and among clients with lower educational levels, but these associations were no longer significant after the effects of drug and alcohol use were taken into consideration.

Drug and alcohol related behaviors also predicted infection:

• As expected, intravenous drug use was the strongest predictor of infection.
• Lifetime alcohol dependence was positively associated with infection in both males and females; the association was stronger among females than males.
• Snorting drugs, higher lifetime frequency of intoxication, and drug psychiatric disorders were also associated with increased rates of HCV, but intravenous drug use and lifetime alcohol dependence explained their relations.

Other behaviors also had an influence:

• Prison experience was significantly associated with infection, particularly among males.
• Other behaviors were initially associated with HCV, such as having 10 or more lifetime sex partners, tattoos, and body piercing, but when intravenous drug use was controlled for, these associations were no longer significant.

 

Conclusions

In this study we replicated earlier findings suggesting that alcoholism is associated with hepatitis C infection, even when intravenous drug use is taken into account, especially in females. It may be that alcoholic drinking weakens the immune system, increasing susceptibility to infection. Alternatively, or possibly in addition, alcoholic drinking may be associated with accidental or intentional injuries that bleed and increase the likelihood of exposure to hepatitis C.

While intravenous drug us is a very potent transmitter of hepatitis C, not all persons with the infection have a history of injecting drugs, and it is important to identify additional risk factors. Prison experience appears to represent such a risk factor, and a series of recommendations have been made to lower the risk in the incarcerated population. Finally, unemployment emerged as a strong risk factor for females, unrelated to the other risk factors such as alcohol dependence, prison experience, or blood transfusions. This association is not explained by poorer health, and we plan to investigate its relation to reports of trading sex for drugs or money.

Interventions such as needle and syringe exchange programs and drug treatment programs that have proven useful in reducing HIV transmission are less effective in preventing the transmission of hepatitis C. Hepatitis C is more infectious than HIV, and it is more prevalent; therefore, drug users are likely to contract hepatitis C early in their injecting careers, before coming into contact with prevention programs. For this reason, researchers are looking for factors among young people that predispose them to inject drugs.

 

Next steps for research and policy implications

We are studying other measures of exposure to blood (such as through violence) and their relation to alcohol and drug use and to hepatitis C infection. We are examining the impact of risky sex behaviors as well as intentional and accidental injuries.

In the future we hope to study the lifetime drinking patterns of patients who have hepatitis C to determine how drinking affects infection rates and how it can be modified to improve the health outcomes of infected people.

The increased knowledge of hepatitis C infection and progression will help in the development of prevention and treatment programs.

 

The Take-Home Message

Hepatitis C is a common and easily transmitted disease that has serious long-term consequences. Identifying and understanding the risk factors for the disease can help us design prevention programs and aim these programs at the most at-risk target groups. We have known for some time that intravenous drug users are particularly vulnerable to this disease. We should also understand that prisoners, alcoholics, and people with other risky behaviors are also more likely to contract the disease. Other behavioral and demographic factors also play a role.

 

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