CATIE News

17 December 2019 

Factors associated with hepatitis C infection among men who take PrEP

  • Sexual transmission of hepatitis C has been observed among men who have sex with men
  • A study of 429 men taking PrEP identified factors associated with hepatitis C infection
  • Hepatitis C was linked to the number of sex partners and sex acts, and drug use during sex

Research has found that when used as directed, pre-exposure prophylaxis (PrEP) is highly effective at reducing the risk of HIV infection. PrEP consists of a pill containing two anti-HIV medicines – tenofovir DF and FTC – sold as Truvada; it is also available in generic formulations.

Testing must be done for HIV and other sexually transmitted infections (STIs) before initiating PrEP and at regular intervals after PrEP initiation. Health assessments should also be done at regular intervals and vaccination against hepatitis A and B viruses in people who do not have immunity to them can be helpful.

Hepatitis C virus

Shortly after the turn of the 21st century, hepatitis C virus (HCV) began to be transmitted among some gay, bisexual and other men who have sex with men (MSM). This virus can infect the liver and cause chronic injury to this vital organ. Research suggests that HCV may be passed from one partner to another in a number of ways, including the following:

  • when equipment for injecting or snorting drugs is shared (e.g., in “chemsex” or “party and play”)
  • in practices that could lead to rectal bleeding (e.g., fisting)
  • during condomless intercourse
  • in situations of group sex, particularly if condoms or gloves are not changed with each new partner
  • when sex toys are not disinfected before being used with a new partner
  • during intercourse in the presence of ulcers or sores caused by STIs

HCV and PrEP

To investigate acute (recent onset) HCV infection among PrEP users, scientists in Montreal and several cities in France revisited data collected over several years in a landmark clinical trial called IPERGAY. This trial demonstrated the effectiveness of PrEP in preventing HIV infection and its findings have been incorporated into PrEP guidelines. In additional analysis of the data from this trial, the scientists focused on medical records, participant surveys and analyses of stored blood samples from 429 MSM.

In an article published in the January 1, 2020 issue of the journal AIDS, the scientists found that 14 MSM were diagnosed with acute HCV infection over the course of two years. According to the scientists, people with acute HCV infection “reported a significantly higher number of sexual acts and/or partners, and more frequent recreational drug use [at the start of the study].”

The scientists reported that tests of participants’ blood samples for HCV-specific proteins and genetic material “were positive within [an average of] two months before the detection of antibodies [to HCV].” The scientists suggested that in the future, healthcare providers could consider using tests for HCV proteins and/or HCV’s genetic material to screen MSM at high risk for HCV infection.

Study details

Participants enrolled in IPERGAY were adult MSM who were HIV negative. They made regular visits to the study clinic (usually every two months), where they provided blood samples and answered detailed questionnaires about their sex lives and their engagement in substance use. Every six months participants were screened for chlamydia, gonorrhea and syphilis.

Screening for HCV was done with the following tests:

  • a test for HCV antibodies in blood samples at the start of the study and every 12 months thereafter
  • a test for elevated levels of liver enzymes in blood samples every two months (these elevations can occur because of liver inflammation caused by HCV infection)

Acute infection

The scientists defined the date of acute HCV infection as the date of the first positive test result for HCV antibodies. For participants who had a positive antibody test result, the scientists screened their previously collected blood samples for HCV-related proteins (antigen) and this virus’ genetic material (RNA).

Results

During the study 14 participants around the age of 30 years were diagnosed with acute HCV infection.

The distribution of major HCV strains (called genotypes) was as follows:

  • genotype 1a – six men
  • genotype 3a – one man
  • genotype 4d – seven men

Behavioural factors

According to the scientists, men who disclosed the following factors at the start of the study were statistically more likely to subsequently develop acute HCV infection than men who did not disclose these factors:

  • “a significantly higher number of sexual partners (17 vs. 8) over the past two months…and a higher number of sexual acts over the past four weeks (18 vs. 10) compared with uninfected [participants]”
  • “oral or snorting drug use during the last sexual act (defined as ‘chemsex’) was also statistically more frequent in HCV-infected patients (57% vs. 11%), especially the consumption of gamma-hydroxybutyric acid or gamma-butyrolactone [GHB/GBL]”

Additional laboratory tests

The scientists investigated whether elevated liver enzymes might be an early sign of acute HCV infection by checking the results of liver enzyme tests done two months before the appearance of HCV antibodies. They found that only 25% of participants who were diagnosed with acute HCV infection had elevated liver enzymes two months earlier.

Also, on average, test results for HCV antigen and/or RNA were positive two months before HCV antibodies appeared. The scientists found the HCV RNA test to be more sensitive (100%) than the antigen test (89%) in screening for acute HCV infection.

Advice for healthcare providers about HCV in PrEP users

The IPERGAY scientists recommended that clinicians screen patients who request or who are using PrEP for the HCV risk factors identified in the present analysis. Such screening, they stated, “appears crucial to identify the most at-risk individual, and to improve HCV screening strategies, prevention interventions and immediate treatment.”

The scientists noted that they are assessing an HCV screening tool (a questionnaire called MOSAIC) developed by doctors in the Netherlands, Belgium and Australia among PrEP users.

Bear in mind

HCV treatment is widely available in Canada and other high-income countries. In general, this treatment is highly effective and can cure more than 95% of cases of HCV infection. Treatment is usually taken once daily by mouth and may need to be taken for as little as eight weeks by some people.

According to the IPERGAY scientists, the use of tests that directly assess the presence of HCV – antigen and RNA – “may allow shortening the delay of acute HCV diagnosis in comparison with HCV antibody-based screening.” They also noted that “an early diagnosis of HCV infection is crucial to prevent the ongoing epidemic. Once diagnosed with acute HCV infection, people can now benefit from specific HCV cure therapy. Rapid introduction of HCV cure therapy following diagnosis is expected to reduce HCV incidence among high-risk MSM on PrEP as it has been observed in HIV-positive individuals.”

Resources

Hepatitis C virus

Hepatitis C Key Messages - TreatmentCATIE

Curing Hepatitis C: What you need to knowCATIE

German researchers dig deep to understand how hepatitis C virus is transmitted sexuallyCATIE News

PrEP

On-demand PEP to prevent HIV infectionCATIE news

Pre-exposure prophylaxis (PrEP) resources and toolsCATIE

Canadian Guideline on HIV Pre-Exposure Prophylaxis and Nonoccupational Postexposure ProphylaxisBiomedical HIV Prevention Working Group of the CIHR Canadian HIV Trials Network

—Sean R. Hosein

REFERENCES:

  1. Gras J, Mahjoub N, Charreau I, et al. Early diagnosis and risk factors of acute hepatitis C in high-risk MSM on preexposure prophylaxis. AIDS. 2020 Jan 1;34(1):47-52.
  2. Newsum AM, Stolte IG, van der Meer JT, et al. Development and validation of the HCV-MOSAIC risk score to assist testing for acute hepatitis C virus (HCV) infection in HIV-infected men who have sex with men (MSM). Eurosurveillance. 2017 May 25;22(21). pii: 30540.
  3. van de Laar T, Pybus O, Bruisten S, et al. Evidence of a large, international network of HCV transmission in HIV-positive men who have sex with men. Gastroenterology. 2009 May;136(5):1609-1617.
  4. Schmidt AJ, Rockstroh JK, Vogel M, et al. Trouble with bleeding: risk factors for acute hepatitis C among HIV-positive gay men from Germany--a case-control study. PLoS One. 2011 Mar 8;6(3):e17781.
  5. Lockart I, Matthews GV, Danta M. Sexually transmitted hepatitis C infection: The evolving epidemic in HIV-positive and HIV-negative MSM. Current Opinion in Infectious Diseases. 2019 Feb;32(1):31-37.