It appears injection drug use is the most common way hepatitis C is transmitted among those infected with HIV, the virus that causes AIDS, says a recent study from a group of Swiss researchers.1
Scant Data on HCV Prevalence in HIV
Information on how hepatitis C is spread among people infected with HIV is "sparse", wrote the team of researchers at University Hospital Berne in Switzerland. Additionally, facts about whether HCV is transmitted by unprotected sexual intercourse in this population, and how often, are "controversial", they wrote.
"The impetus [for this study] was the stories among researchers about HCV—miniepidemics among HIV-infected men who have sex with men, and the availability of the respective prospective data in our cohort," explained study leader Hansjakob Furrer, MD, in the hospital's division of Infectious Diseases.
In hopes of helping to increase knowledge about this aspect of hepatitis C, the research team pulled records on nearly 8,000 HIV patients who had taken part in an unrelated Swiss study between 1988 and 2004. They looked at the relationship between hepatitis C infection and how each person acquired HIV, their sexual practices, injection drug use, and condom use.
Impact of Injection Drug Use
Furrer and his associates learned that, overall, the prevalence of HCV infection was 33% among these patients. However, 90 percent of them with the viral infection had reported previous injection drug use. The number of cases of HCV among HIV-infected injection drug users was nearly 30 times that of those who reported no such use, the study found. "We suppose that transmission among IDUs [injection drug users] in our cohort is through their handling of injecting instruments," Furrer told Priority Healthcare. "This may be needle-sharing, but could also be sharing other [drug paraphernalia] like filters [or] spoons."
By comparison, the incidence of hepatitis C infection was much lower among those without a history of injection drug use, even in cases involving unsafe sexual practices, such as intercourse without the use of a condom. Among those who reported they did not inject drugs and practiced safe sex, the incidence of hepatitis C infection was the lowest.
"HCV infection incidence in the Swiss HIV Cohort Study was mainly associated with injection drug use," Furrer and his associates wrote. "In HIV infected MSM [men who had sex with men], HCV infection was associated with unsafe sex."
The findings strongly suggest that more education is necessary for men infected with the AIDS virus who practice unsafe sex or HIV-infected people who inject illicit drugs, Furrer stressed. "But we doubt that education alone is sufficient," he said. "And integral programs are difficult to build up."
He explained the findings are "disappointing" because they reflect the inability to educate people with HIV who inject illicit drugs about the risks of transmitting HCV. That's the case, he said, in a country that has high standards of needle exchange and substitution programs.
HCV Heterosexual Transmission
This study mostly focused on homosexual men who have been diagnosed with HIV. According to the Centers for Disease Control and Prevention, while there is a risk of contracting hepatitis C from heterosexual activity, it is very small. The National Institutes of Health puts it at around 0.6% for couples who are in long-term monogamous relationships when only one partner is infected. Those who have multiple sex partners, however, face a somewhat higher risk of contracting hepatitis C from their partner.
As such, those infected with HCV who have multiple sex partners or are in short-term relationships are advised to use condoms to provide additional protection against transmitting the virus.2
Meanwhile, in research published earlier this year on the topic,3 a team of French doctors wrote: "Liver disease is now a leading cause of death among HIV-HCV co-infected patients, and is becoming an important cause of death among HIV-HBV co-infected patients. The risk of death from liver disease is highest in patients co-infected by both HCV and HBV."
Other experts describe HCV/HIV co-infection as an "opportunistic" pathology that could have a "catastrophic" effect on associated disease and death in diagnosed patients. For one, HIV can accelerate the progression of liver fibrosis in those infected with hepatitis C, experts have maintained. Treatment for people with both infections is also expensive, associated with severe side effects, and provides only a "modest cure".4
1. Rauch A, Rickenbach M, Weber R et al. Unsafe sex and increased incidence of hepatitis C virus infection among HIV-infected men who have sex with men: the Swiss HIV Cohort Study. Clin Infect Dis 2005 Aug 1;41(3):395-402. Epub 2005 Jun 21.
2. Hepatitis Neighborhood. How is Hepatitis C Transmitted from Person to Person? Available at: http://www.hepatitisneighborhood.com/content/understanding_hepatitis
/what_is_hepatitisc_123.aspx. Accessed August 25, 2005.
3. Salmon-Ceron D, Lewden C, Morlat P et al. Liver disease as a major cause of death among HIV infected patients: role of hepatitis C and B viruses and alcohol. J Hepatol 2005 Jun;42(6):799-805.
4. Kottilil S, Jackson JO, Polis MA. Hepatitis B & hepatitis C in HIV-infection. Indian J Med Res 2005 Apr;12194):424-50.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.