How many prison inmates with a history of recent drug use are thought to be infected with hepatitis C (HCV)?
Prisoners overall have a very high rate of past or present injection drug use, which is a major risk factor for HCV infection due to repeated exposures to needles.
We are experiencing an epidemic of injection drug use and HCV among young persons in Massachusetts. About a quarter of all inmates entering the state prison system in Massachusetts that we asked report positive tests for HCV.
How is HCV screened for?
First we have to decide whom to screen for HCV infection. CDC recommends testing of high-risk populations, which include injection drug users, those receiving blood products before 1992, and those born between 1945 and 1965 whose risks are in the distant past and often are unrecognized.
Next we need to know how to screen. Most clinicians know to check an HCV antibody, which indicates exposure to the virus. This is usually a blood test that is sent to a laboratory and thus takes time for results; recently the FDA has also approved a rapid test that can be administered at the point-of-care.
Then, those positive for exposure should be confirmed and tested for active infection that tests for the virus directly via molecular detection.
Why is it important to screen people for HCV?
HCV is generally a silent infection, whether identified during the early or “acute” phase or during the later “chronic phase.” Chronic infection can result in a silent progression to cirrhosis, which then can result in liver cancer and other complications.
Hepatitis C virus is the leading cause of chronic liver disease and cirrhosis in the United States and the main reason why a liver transplantation might be needed. It kills tens of thousands of Americans each year--more people than HIV--and is a leading cause of death of adults born between 1945 and 1965.
Effective treatment that cures this virus is already available, and cure dramatically reduces the risk for these liver complications. There are newer drugs in development that promise even better cure rates with the added bonus of fewer side effects. Whenever we have better treatments for conditions that are asymptomatic, the rationale to screen is even greater.
Is it possible to be infected with HCV and have no symptoms?
Absolutely. With the majority of patients exhibiting no symptoms, identifying patients at high-risk requires knowing their history.
How did your recent research into the systematic screening of intravenous (IV) drug users who are new to the prison system originate?
Over a decade ago, an infectious disease physician, Barbara McGovern, was working in the prison system and was inspired by a study that noted that treating acute HCV was much more effective than treating chronic HCV. She noted that in 25 patients referred for acute hepatitis, 21 had new HCV as the most likely cause.
Our research group at Massachusetts General Hospital was studying how the immune system fights off this virus, as a proportion of people can clear HCV entirely on their own. Understanding this can lead to the basis of a preventive vaccine.
Together, we wanted to test the hypothesis that asking the right questions might lead to a more efficient diagnosis, compared to a strategy that evaluated those with symptoms or elevated liver function tests. The National Institutes of Health helped fund these studies.
What did your research involve?
Our primary goal was to find those in the first six months of HCV infection. We implemented a brief question based approach to find the highest-risk individuals for HCV. First we excluded those who already reported HCV positive tests in the past, as these are likely old infections.
Providers then asked simple questions about whether the patient injected drugs. If they did, we asked when they began and whether there was a change in injecting patterns, such as sharing needles with a new partner.
By focusing on changes in behavior in the past year, we were able to narrow the thousands of inmates into smaller group of high-risk patients for more intensive diagnostic approaches.
What did your research find?
About 1% of incoming inmates were diagnosed with acute HCV infection, normally a rare and difficult diagnosis. We were able to identify acute HCV infection at triple the rate of a previous study period relying mostly on elevated liver function tests.
We also found that young African-Americans in our state were much less likely to report positive HCV tests and inject drugs – this finding has important implications for targeting of preventive measures.
Why don’t many healthcare programs in correctional facilities routinely screen for HCV and are there plans in place to change this?
Correctional facilities are concerned about HCV but often do not have the time or resources to devote to HCV screening. We hope our history-based approach can help them make new diagnoses of HCV in an efficient manner.
There is also rationale to increase screening for HCV in jails, highlighted by a recent editorial in the Journal of the American Medical Association (Spaulding and Thomas JAMA. 2012 Mar 28;307(12):1259-60).
What impact do you think your research will have?
We hope that others will implement this relatively simple screening strategy in medical settings in the incarceration system, which provide an important “window” into the epidemic of HCV. This strategy can also be used in other medical settings highly likely to encounter acute HCV, which include opiate substitution clinics, detoxification centers, and emergency rooms.
We also hope this will inspire more research into why young African-Americans are less likely to inject drugs than their Caucasian counterparts.
Recent research published in the March issue of Hepatology suggested that HCV is rarely transmitted through sex between monogamous heterosexuals. How does the risk of HCV transmission through sexual activity compare to that of IV drug use?
The risk after exposure to a contaminated needle is quoted as 1-3%. That’s much higher than the 1 in 190,000 risk calculated by Dr. Terrault’s informative study.
While each individual exposure to contaminated blood is not very high risk, those using intravenous drugs may expose themselves repeatedly. Often they try to be careful to not expose themselves by using clean needles and equipment but this is hard to maintain.
Thus, perhaps a third of those initiating injection drugs contract HCV in the first year after use, and more contract it the longer they inject. Clearly there is a lot of work that needs to be done to prevent new infections, especially as injection drug use is increasing in many areas of the United States.
Where can readers find more information?
A good place to start is the CDC website, with many useful links regarding HCV epidemiology. http://www.cdc.gov/hepatitis/HCV/index.htm.
Our state’s Department of Public Health has reported our epidemic http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6017a2.htm.
I would like to also point out that we belong to a larger collaborative network of investigators examining acute HCV infection in injection drug users based at the University of California, San Francisco: https://www.ucsf.edu/.
About Dr Arthur Kim
Dr. Kim graduated from Harvard Medical School and trained in internal medicine / infectious diseases at the Massachusetts General Hospital.
His research, currently funded by the National Institutes of Health, has focused on the immunology of HCV infection, particularly in special populations such as those acutely infected or those with HIV infection. He has published several manuscripts in the immunologic, virologic and clinical aspects of HCV in these populations.
Dr. Kim is Assistant Professor of Medicine at HMS and directs the viral hepatitis clinic in the infectious disease division at MGH.
He is currently serving on the Hepatitis Transformative Science Group Subcommittee of the AIDS Clinical Trial Group network.
Fine particulate matter exposure linked to increased hospital admissions for major diseases