HIV Weekly - 17th April 2013

Hepatitis C in gay men

Hepatitis C virus (HCV) transmissions have been occurring in gay men since the early years of the HIV epidemic, new research shows. Analysis of stored blood samples found evidence of transmissions dating back to the early 1980s.

There are ongoing outbreaks of sexually transmitted hepatitis C among gay men in the UK as well as in a number of other European countries and the United States. Almost all the infections involve HIV-positive men.

These outbreaks became a matter of concern in the early 2000s and little was known about the rate of new transmissions before this.

Researchers in the US therefore examined stored blood samples obtained from over 5000 gay men involved in the MultiCenter AIDS Cohort Study (MACS). They looked at samples collected between 1984 and 2011. None of the men were infected with HCV when they were recruited to the study.

A total of 115 new hepatitis C infections were recorded.

The rate of new infections was eight times higher in men with HIV compared to HIV-negative men. This underlines what’s already known – that the majority of hepatitis C transmissions in gay men involve those with HIV.

Transmissions were recorded as early as 1984.

Hepatitis C is a bloodborne virus and injecting drug use was found to be a major risk factor for infection.

But there was further evidence showing that infections are also linked to unprotected anal sex.

The researchers believe their findings underscore the need for hepatitis C prevention information to be targeted at gay men, especially those with HIV.

Separate research conducted in the UK has shown that the proportion of HIV-positive gay men reporting unprotected anal sex increased from 74% in 2001 to 82% in 2008.

Other known risk factors for sexual transmission of hepatitis C in HIV-positive gay men include sexual practices that could cause bleeding such as fisting, as well as group sex and drug use.

We’ve recently published four illustrated leaflets giving basic information about hepatitis C, including How hepatitis C is passed on during sex.

HIV treatment as prevention

Levels of HIV viral load differ in the genital fluids of men and women, according to new research.

Viral load was higher in the genital fluids of women than men, even in the presence of antiretroviral therapy that suppressed viral load in the blood to undetectable levels.

The study involved people in Brazil, India, Malawi, Peru, South Africa, the United States and Zimbabwe. Viral load in blood and genital fluids was monitored at baseline and again after 48 and 96 weeks of treatment.

After 48 weeks of treatment, genital fluid viral load was undetectable in 84% of women and 96% of men. This difference persisted at week 96.

There was some evidence that viral load differed according to HIV subtype, being higher among people with subtype C, which is common in sub-Saharan Africa.

The investigators suggest their findings may have implications for the use of HIV treatment as prevention.

However, it is open to question whether people taking effective HIV treatment who nevertheless have detectable virus in their genital fluids are actually infectious.

The large HPTN 052 study showed that antiretroviral therapy that suppressed viral load in the blood reduced the risk of transmission by 96%. The study was conducted in settings where subtype C virus is common. If low-level genital tract replication is widespread among women taking antiretroviral therapy, it does not appear to have translated into a real risk of transmission in the only large randomised study of the impact of antiretroviral therapy on sexual transmission conducted to date.

Separate research suggests that treatment will not be enough to end the HIV epidemic among gay men in the United States.

Researchers developed a mathematical model to predict the impact of treatment on future HIV transmissions.

It showed that even if all gay men were promptly diagnosed and started immediate treatment, the rate of new infections would still be higher than the HIV-related mortality rate in gay men.

However, the model did show that a ‘test and treat’ strategy would have a big impact on the number of new infections.

Expanding the number of people taking treatment would also lead to substantial reductions in HIV-related mortality. The model assumed that drug-resistant virus would be a contributory cause to these deaths, but didn’t take account of recent advances in HIV treatment which mean that an undetectable viral load is now a realistic aim for almost everyone.

For more information on HIV treatment as prevention, read our online factsheet, or find out more about previous studies in our Preventing HIV resource.

Prognosis and outcomes

There’s more evidence of the dramatic impact of antiretroviral therapy on prognosis.

Research conducted in South Africa shows that people who started treatment with a CD4 cell count above 200 had a “near normal” life expectancy.

This is one of the first studies from a resource-limited setting to show that HIV treatment can lead to substantial increases in life expectancy.

People who started treatment when their CD4 cell count was above 200 had a life expectancy of approximately 80% of that of matched controls.

It’s likely that many people have a much better prognosis than that suggested by the study.

The research was based on people who started treatment between 2001 and 2010. People living with HIV became eligible for treatment when their CD4 cell count fell below 200 or if they developed symptoms. However, World Health Organization (WHO) guidelines now recommend that people with HIV should start antiretroviral treatment when their CD4 cell count is around 350.

Research conducted in the UK and other European countries shows that most people taking HIV treatment now have a normal life expectancy and can expect to live well into old age.