When we think of viral hepatitis and injection drug users (IDUs), we usually think of hepatitis C. But hepatitis A also poses a significant threat to IDUs. Here's why:
Hepatitis A can be transmitted through blood, so sharing needles and injection equipment (cookers, cotton, water) could put IDUs at risk for hepatitis A
A study in Baltimore from the mid-1990s found that 66% of IDUs had been infected with hepatitis A (see PDF of article from Clinical Infectious Diseases). More recently a Vancouver study found evidence of past hepatitis A infection in 43% of IDUs (full text of article from Canadian Medical Association Journal; PDF here)
The Centers for Disease Control (CDC) reports that 5% of all new cases of hepatitis A in the United States occur among IDUs – but since half of all new cases have no reported risk, this figure may underestimate the rate of new infections in IDUs.
Hepatitis A is rarely fatal. But if you already have hepatitis C, getting hepatitis A can cause fatal liver failure (see abstract in New England Journal of Medicine).
The good news is that hepatitis A is almost totally preventable through vaccination. Injection drug users and people with hepatitis C should be vaccinated for hepatitis A.
The largest hepatitis A outbreak ever recorded in the United States happened last year when at least 660 people who ate contaminated green onions at a Chi-Chi’s restaurant in Pittsburgh got sick. Four people have died from liver failure as a result (see news stories here and here).
Hundreds of others got sick from contaminated green onions at other restaurants in Georgia, North Carolina, and Tennessee. The green onions came from four Mexican farms, which have since been shut down (news story here).
Hepatitis A is fairly common in the United States; about a third of all Americans have been infected at some point. Contaminated food is a major source of hepatitis A, which is largely associated with fecal-oral transmission (see CDC fact sheet). Household contact and oral-anal sex (rimming) can also transmit hepatitis A.
Hepatitis A can cause jaundice, fatigue, nausea, fever, diarrhea, loss of appetite, and abdominal pain. Between 11% and 22% of adults who get hepatitis A need to be hospitalized. Hepatitis A is very rarely fatal -- less than 1% of all cases overall, but more likely in people over 40.
There's no specific treatment for hepatitis A, though sometimes immune globulin (a batch of antibodies to hepatitis A) is given for recent (<2 weeks) exposures, where it is at least 85% in preventing hepatitis A. Alternately, some evidence supports the use of hepatitis A vaccine (see below) following exposure, and vaccination is sometimes used to control outbreaks (with or without immune globulin). Various medications can be used to manage symptoms.
Everyone ultimately clears hepatitis A infection, typically after a few weeks or, in some cases, several months. But during acute infection, the virus becomes detectable in feces and in blood before any symptoms or clinical signs of infection. This period is when hepatitis A is transmissible. One study found that the hepatitis A virus remains present at detectable levels in the blood for an average of about three months (full text; PDF), though periods exceeding a year have been reported (abstract).
Several outbreaks of clustered cases among networks of IDUs have been documented, but it’s not clear how much of hepatitis A transmission among IDUs occurs directly through needle and injection equipment sharing. Using contaminated sources of water (for instance, from toilets) to prepare drugs for injecting could also be a source of infection. Other environmental factors could also increase transmission through poor hygiene in shooting galleries, shelters and jails, crowded apartments, etc.
The hepatitis A vaccine is highly effective, offering nearly 100% protection. The vaccine is given in two shots, at least six months apart. Even getting just one shot provides up to 90% protection. Some key points:
The hepatitis A vaccine now comes in a combination with the hepatitis B vaccine, given in a 3-shot series (i.e., today, a month from now, and six months from now)
If you miss a scheduled shot in the vaccine series, you don’t need to start over from the beginning (see Interrupted hepatitis vaccine schedules, Miriam Alter, Cleveland Clinic Journal of Medicine, June 2003 – one-page PDF)
If you’ve already had hepatitis A, you don’t need to be vaccinated – you’re immune to getting it again. But the vaccine is safe, even if you’re already immune. You generally don’t need to be tested to see if you’re already immune before getting the vaccine.
Vaccination for hepatitis A provides protection for over 10 years, and likely at least 20 years. For now there’s no recommendations on getting periodic booster shots (see Hepatitis A booster vaccination: is there a need? Van Damme et al. for the International Consensus Group on Hepatitis A Virus Immunity, Lancet, September 2003 – summary here)
People with HIV, especially those with low CD4 T cell counts, may not respond as well to hepatitis A vaccination. A recent study reported that out of 103 people with HIV receiving hepatitis A vaccinations, only half were effectively protected from infection, as measured by antibody levels (abstract; PDF of poster presentation). People with HIV can have their antibody levels checked to see if they’re protected, and may need a second round of hepatitis A vaccination.
It’s easy to get confused about the differences between the hepatitis viruses. In our recent trainings and education sessions at needle exchange/harm reduction programs, both participants and staff have a lot of questions about these differences.
This confusion extends to information people get from their health care providers – a lot of people report being told that they have, or once had, hepatitis but it’s gone, or it’s not serious, or they only have traces of it in their blood. People often don’t know which form of hepatitis they had or have, and whether they’ve been vaccinated.
For a one page chart listing the differences between hepatitis viruses (A through E), see page 11 of the training manual for Understanding Hepatitis C: A Training for Service Providers (80 page PDF), a curriculum for the New York City Department of Health and Mental Hygiene (NYC DOHMH) by the AIDS Community Research Initiative of America (ACRIA); see also the accompanying participant manual (PDF)
Below are some additional resources, fact sheets, and reference material.
Resources and Further Reading
from the CDC:
Hepatitis A Vaccine: What You Need to Know (CDC fact sheet, 2-page PDF)
CDC Hepatitis A links and resources - brochures, statistics, vaccine information, etc.
Immunization Action Coalition - a valuable source of information and resources on vaccinations and a leading advocate for expanding adult immunization -- see their one-page PDF calling for hepatitis A and B vaccinations for high-risk groups, including IDUs. Their hepatitis A section is here.
Hepatitis A virus infections in injecting drug users, NS Crowcroft, editorial in Communicable Disease and Public Health [CDPH], June 2003) – PDF
Changing epidemiology of hepatitis A: should we be doing more to vaccinate injecting drug users? Perrett et al., CDPH, June 2003 – summary
Outbreak of hepatitis A infection among intravenous drug users in Suffolk and suspected risk factors. Sundkvist et al., CDPH, June 2003 – summary
Clinical Practice: Prevention of Hepatitis A with the Hepatitis A Vaccine. Craig and Schaffner, New England Journal of Medicine, January 2004 – extract