February 25, 2016
New infection with hepatitis C virus (HCV), which can cause serious liver disease, rose consistently from 1991 through 2012 in a study of more than 13,000 HIV-positive gay or bisexual men in the United States, Europe, and elsewhere.1 Many new HCV infections could be explained by rough anal sex or party-drug use.
Like HIV, HCV can be passed from person to person during sex or when sharing needles or other injection equipment. As a result, people with HIV run a high risk of HCV infection, and people with HCV run a high risk of HIV infection. HCV attacks the liver, where it can lead to liver cancer or destroy liver cells and prevent healthy liver function. Liver fibrosis gets worse faster in HCV-infected people with HIV than without HIV.
Over the past 10 to 15 years, health workers in the United States, Europe, Australia, and Asia have reported outbreaks of new sexually transmitted HCV infection in HIV-positive gay or bisexual men. Several factors raise the risk of sexual HCV transmission in HIV-positive gay men: (1) high HCV levels resulting from HIV infection, (2) rough sex that leads to bleeding (blood carries HCV), (3) open sores resulting from sexually transmitted diseases, and (4) frequent or long sex because of party-drug use. Strong anti-HCV drugs make it possible to cure HCV infection in most people. But these drugs are expensive, and people cured of HCV infection can get infected again if they continue the same risky behaviors.
To get a better understanding of trends in new HCV infection and reinfection after cure, New York University researchers analyzed findings from studies that measured HCV rates in HIV-positive gay and bisexual men around the world.
The researchers checked electronic databases and medical conference materials for studies that appeared between January 1990 and February 2015. They included studies that measured rates of new acute HCV infection or another HCV infection after HCV cure in HIV-positive gay or bisexual men. The researchers also included studies of risk factors for acute HCV infection or HCV infection after cure, even if those studies did not report rates of new HCV infection. The analysis did not include findings on new HCV infection in people infected while injecting drugs.
The research team used standard methods to combine new HCV infection rates from individual studies. They used the same methods to combine new HCV rates after HCV cure. Combining data in this way gives a stronger overall view of new HCV rates across different populations of gay or bisexual men with HIV.
Then the investigators analyzed the impact of study year (1998 to 2011) on new HCV rates in men with HIV to see if those rates changed over time. They also examined the impact of behavioral factors on new HCV rates in individual studies. They could not combine the behavioral data for further analysis because individual studies reported behavioral findings in different ways. For individual studies, the researchers calculated the population-attributable risk for various behaviors. Population-attributable risk is the proportion of new HCV infections in the study population that can be explained by specific risk behaviors.
The analysis of new HCV infections involved 17 studies, half of them from Europe, four from the United States, three from Asia, and two from Australia. Together, the studies took place from 1984 through 2012. These studies included more than 13,000 HIV-positive gay or bisexual men, all of them living in prosperous countries.
Acute HCV infection developed in 497 of these men. When the researchers combined results of these 17 studies, they calculated a new-HCV rate of 0.53 per 100 person-years. That rate means about 5 of every 1000 men got infected with HCV every year. The new-HCV rate (incidence) rose from 0.42 per 100 person-years in 1991 to 1.09 per 100 person-years in 2010 and to 1.34 per 100 person-years in 2012 (Figure 1).
Figure 1. Analysis of 17 studies of HIV-positive gay or bisexual men determined that the rate of new HCV infection more than tripled from 1991 to 2012, climbing from 0.42 to 1.34 per 100 person-years. A rate of 1.34 per 100 person-years means about 13 of every 1000 men became infected with HCV every year. (HCV illustration from Servier PowerPoint Image Bank.)
Two studies had data on how often HIV-positive gay or bisexual men got infected with HCV after drug therapy had cured an earlier bout of HCV infection. Reinfection incidence measured 9.6 per 100 person-years in a London group and 15.2 per 100 person-years in an Amsterdam group. Combined HCV reinfection incidence in these two studies was 11.4 per 100 person-years, meaning about 11 of every 100 HIV-positive men cured of HCV got infected with HCV again every year. In these two studies, 25% to 33% of men got infected with HCV again within 2 years of being cured.
A few studies in the United States and Europe identified three practices that made HCV infection more likely -- rough anal sex, sex without condoms, and party-drug use (Figure 2). In a New York City study, receptive anal sex (being the bottom) without a condom boosted chances of HCV infection 23 times.2 The population-attributable risk for receptive anal sex without a condom was 22%. In other words, 22% of new HCV infections among HIV-positive gay men in the study area could be blamed on receptive anal sex without a condom. In a study of HIV-positive German men, sex that led to rectal bleeding raised chances of new HCV infection 6.2 times, and the population-attributable risk was 3.8%.3 Frequent receptive fisting without gloves or with shared gloves upped chances of new HCV 5.7 times for a population-attributable risk of 4.9%. In HIV-positive gay or bisexual Swiss men, inconsistent condom use doubled chances of new HCV infection, and the population-attributable risk was 26.7%.4
Figure 2. Analysis of studies involving HIV-positive gay or bisexual men identified three groups of factors that raised chances of new HCV infection. All of the individual factors shown in the bullet lists at right raised chances of HCV infection regardless of whatever other risk factors a man had.
In the HIV-positive New York City men, having sex while high on methamphetamine raised chances of new HCV infection 28.6 times, and the population-attributable risk was 3.9%.2 In the study of German men, using nasally inhaled drugs like cocaine or ketamine more than tripled the odds of new HCV infection, and the population-attributable risk reached 36%.3
This comprehensive worldwide study found a high rate of new HCV infection in HIV-positive gay or bisexual men. And the new-infection rate is rising steadily, more than tripling from 1991 to 2012. The studies analyzed did not include new HCV infections resulting from sharing needles and other drug-injecting equipment. Thus the new HCV cases recorded show that these men were picking up HCV during sex, through blood or semen. In fact, some of the studies specifically linked rough anal sex, sex without condoms, or sex while taking party drugs to a higher chance of new HCV infection.
Analysis of a few studies showed that HIV-positive men cured of their HCV infection by anti-HCV drug therapy got infected with HCV again at a rate 20 times higher than the initial infection rate in the whole group. Two years after being cured of HCV infection, one quarter to one third of these men picked up a new HCV infection. Findings like these show that some HIV-positive gay or bisexual men continue having sex without condoms despite picking up other sexually transmitted diseases like HCV.
Hepatitis B virus (HBV) can also pass from person to person during sex. There is a vaccine to prevent HBV infection -- and everyone with HIV infection who does not already have HBV infection should get the HBV vaccine.5 But there is no vaccine to protect from HCV infection. The only ways to avoid HCV are to avoid sex without condoms, to avoid sharing drug-injecting equipment, and to avoid other risky behaviors. (See "What Sexually Active HIV-Positive People Should Do About HCV.")
HCV infection causes no symptoms for years. The only way to know if you're infected is to get tested. U.S. health authorities recommend that all HIV-positive people should have liver enzyme levels tested when they start care, and sexually active HIV-positive people or drug injectors should have this test every year.5 Anyone with high liver enzymes should be tested for HCV in the blood to see if HCV infection is driving up liver enzyme levels. HCV infection can often be cured by new anti-HCV drugs, but these drugs are extremely expensive.
Besides harming the liver, HCV infection may raise the risk of death in people with HIV, may speed up development of AIDS diseases and non-AIDS diseases, and may affect the response to antiretroviral therapy.7 HIV-positive people who have sex or inject drugs should be aware of HCV infection and should do everything possible to avoid it.
|What Sexually Active HIV-Positive People Should Do About HCV|
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