HIV-negative men who have sex with men (MSM) appear to be contracting acute hepatitis C (HCV) through sexual practices, rather than via parenteral transmission, according to a study presented by Katie McFaul, M.D., at ICAAC 2014 in Washington, D.C.
The study identified 44 cases of acute HCV infection in HIV-negative MSM over a four-year period, which McFaul acknowledged may not sound like a high prevalence, but the hospital wasn't looking for HCV in this population.
"If you don't take the temperature, you won't find the fever," McFaul said. "HIV-negative MSM remain at risk of hepatitis C infection because we know that they share similar risk behaviors as HIV-positive MSM."
On the other hand, there may not be a high burden of HCV among HIV-negative MSM in every setting -- or at least not yet, according to another study among HIV-negative MSM from the Lemanic region of Switzerland presented by Matthias Cavassini, M.D., of the University of Lausanne. This study performed rapid screenings of 654 consenting MSM and only found one case of HCV (a prevalence of 0.15%) in an HIV-negative man. However, a survey conducted in the same men found that more than half lacked basic knowledge of HCV -- and sexual practices that could put MSM at risk were commonplace in the cohort -- leading Cavassini to ask, "Is this an accident waiting to happen?"
Most HCV infections are acquired after blood-to-blood contact via parenteral transmission -- either blood transfusions (before screening began), tattooing and body piercing, occupational exposure, medical procedures, and intravenous drug use. As increasing numbers of MSM have been injecting drugs recreationally -- engaging in "slamming" or "chem sex" -- the prevalence of HCV is increasing.
However, sexual transmission of HCV has also been reported among HIV-positive MSM who engage in specific sexual practices, particularly in the past few years. Factors relevant to transmission in this group include traumatic sexual practices (such as fisting and sharing sex toys), sexually transmitted diseases (such as chlamydia and gonorrhea) and increasing numbers of sexual partners including those who engage in drug use.
Given the high and increasing prevalence, screening for HCV in HIV-positive MSM is widely recommended. But as both Cavassini and McFaul pointed out, this is not being done in HIV-negative men and thus HCV prevalence among the HIV-negative MSM population is unknown. However, they are engaging in the same high-risk behaviors as HIV-positive men.
The Swiss Study
In the Swiss study, the participants reported a median of five sexual partners (range 0-400); 52% had been screened for STDs and 11% had an STD diagnosis in the last year.
Of the high-risk factors for HCV:
- 12% had tattoos (often overseas) and 13% had piercings.
- 33% reported using drugs -- the vast majority currently or within the last 12 months, though only a minority were injecting drugs.
- 55% of the participants reported unprotected anal intercourse (47% with casual partners and 26% with anonymous partners).
- 20% of the participants had engaged in traumatic sexual practices (about half with casual and a quarter with anonymous partners).
The sole participant who was identified with HCV reported no high-risk factors for HCV other than unprotected anal intercourse with two partners in the previous year.
Notably, individuals known to be HCV positive were excluded so the prevalence of HCV may be underestimated. However, given that injecting drug use is not very common in this community, it is possible fewer sex partners had the virus, and thus, there is very little transmission at this time. But Cavassini stressed, the combination of low awareness and high-risk behavior could be quite dangerous.
The London Study
McFaul suggested that there could be a heightened risk for MSM in London, however. She and her colleagues conducted a retrospective chart review to identify the HIV-negative MSM who had attended sexual health clinic services from January 2010 to May 2014 who had been diagnosed with acute hepatitis C, as defined by European AIDS Treatment Network (NEAT) criteria and to review the institutions rate of HCV screening.
Forty-four cases of acute HCV were identified by NEAT criteria. Of these individuals, the median age was 37 years old, the median amount of partners in the previous three months was two, the median baseline HCV viral load was about 300,000, and the median ALT (alanine aminotransferase; an indicator of liver damage) levels were 88 iu/L. Genotype was only available in 22 patients: 19 genotype 1, one genotype 3 and two genotype 4.
The patients were tested for HIV at the time of HCV diagnosis, with 35 of the 44 patients getting subsequent HIV testing and remaining negative. The other 9 had no further HIV tests.
The risk behaviors observed with these patients were as follows:
One-third previously had an STD.
The majority of engaged in unprotected anal sex:
- Insertive and receptive, 82%.
- Receptive, 9%.
- Insertive, 2%.
One-third reported engaging in group sex.
One-third engaged in fisting.
One-third engaged in chem sex.
About half reported using recreational drugs at any time.
"Chem sex is something we're seeing a lot more of specifically in London, and that's using recreational drugs during sex. The drugs that are being used include cocaine, ketamine, gamma-hydroxybutyric acid [GHB], mephedrone and crystal methamphetamine. This is something that we're seeing more and more of particularly in our MSM population," McFaul said.
As already noted, clinics don't routinely screen for HCV in HIV-negative men. McFaul found that only 14.8% of the HIV-negative men visiting these sexual health clinics had been screened. Considering that translated to more than 34,000 visits, the incidence of acute HCV transmission is still not great, but the identified cases could be just the beginning.
"HIV-negative MSM remain at risk of HCV because we know that they share similar risk behaviors as HIV-positive MSM. A minority of our cohort report injection and nasal drug use, and we think this supports the hypothesis for sexual transmission in this population as well as in the HIV-positive population. We suggest that hepatitis C screening should be performed at routine sexual health screening, particularly in individuals with risk factors and in environments where there is a high hepatitis C prevalence," McFaul concluded.
Theo Smart is an HIV activist and medical writer who joined ACT UP New York in 1988 and moved to Cape Town, South Africa, in 2000. As a writer and editor, he has more than 20 years of experience writing and editing about HIV treatment for organizations including ACT UP's Treatment & Data Committee, TAG, the PWA Health Group, GMHC, the Physician's Research Network in New York, amfAR, HIV and AIDS Treatment in Practice (HATIP), and NAM/AIDSmap. He covers human rights, the scale up and delivery of HIV and TB care and treatment services, maternal and child health and revitalizing primary health care and health systems strengthening in resource-limited settings. He also follows the development of targeted health services for people who inject drugs, sexual minorities and commercial sex workers in concentrated epidemics.