HIV treatment as prevention

A small study suggests that a combination of the anti-HIV drugs etravirine (Intelence) and ritonavir-boosted darunavir (Prezista) might be a good option for use as HIV treatment as prevention for gay men.

US researchers found that both drugs rapidly achieved good concentrations in semen and rectal tissue and could therefore help prevent the transmission of HIV.

There’s currently a lot of interest in the use of HIV treatment in prevention. The aim of HIV treatment is to reduce the amount of virus in the blood to very low levels (often described as ‘undetectable’, as it is below the level that can be detected by routine viral load testing). As well as keeping people well, effective HIV treatment which suppresses viral load in this way also reduces the risk of HIV being passed on during sex. Research in heterosexual couples showed that suppression of viral load with treatment reduced the risk of transmission by 96%.

Although using condoms is an excellent way of preventing HIV, other methods of prevention are being explored. The same anti-HIV drugs that are used to treat HIV can also be used as pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP), in people who are HIV negative.

Rates of HIV transmission remain high in men who have sex with men. To know if treatment as prevention could work effectively for this group, it is important to understand how well anti-HIV drugs reach semen and rectal tissue, as well as blood.

In this study, doctors monitored concentrations of darunavir/ritonavir and etravirine in the semen and rectal tissue of twelve HIV-negative men. Drug levels were monitored over an eight-day period.

Both drugs were rapidly detected in semen and rectal tissue, and concentrations accumulated over the course of the study. Researchers think that the drugs were present in semen at levels that would effectively suppress viral load.

The researchers were encouraged by their findings and call for further research examining the effect of these drugs on viral load in semen and rectal tissue.

The World Health Organization has also set out a plan for the worldwide use of HIV treatment as prevention.

To reduce the risk of transmission, WHO recommends that HIV treatment should be used by all HIV-positive people who have an HIV-negative partner, regardless of their CD4 cell count.

In UK treatment guidelines, people with an HIV-negative partner are one of the groups recommended to consider early treatment.

For more information, read or download our factsheet on HIV treatment as prevention, or visit the HIV treatment as prevention section of our online Preventing HIV resource for more detailed information on studies to date.

HIV and hepatitis C

Doctors in Europe and the US disagree about the pace of liver damage in HIV-positive men who have recently been infected with hepatitis C.

There’s an epidemic of sexually transmitted hepatitis C in HIV-positive gay men in many countries.

A few years ago, researchers in the US found evidence that hepatitis C caused rapid hardening of the liver (fibrosis).

Doctors in Europe have also looked at liver damage in HIV-positive men recently infected with hepatitis C.

They used a test called Fibroscan to monitor liver stiffness in 38 people. Liver stiffness has been shown to be a good predictor of fibrosis.

Their results showed rapid progression of liver stiffness in the first few months after infection with hepatitis C. But this then slowed, and the pace of disease became similar to that seen in people with longer-term hepatitis C infection.

Hepatitis C treatment has the best chance of working if it is used in the first year or so after a person is first infected with hepatitis C.

While European doctors recognise the importance of early treatment, more effective anti-hepatitis C drugs are in development, which increase the chance of a cure. The doctors therefore think that people who don’t need to take treatment straight away and would prefer not to, can safely wait for more effective therapy to become available.

But the US doctors who first found evidence of rapid fibrosis in co-infected men do not agree that the pace of liver damage slows.

They performed liver biopsies on 29 men with HIV and hepatitis C. This test is considered the ‘gold standard’ by many doctors, but it can cause pain and discomfort.

Results of these biopsies showed that longer duration of hepatitis C infection was associated with a worsening of fibrosis.

The US doctors think that the test used by the European researchers led to them over-estimating the extent of the liver damage caused during the early stages of infection and therefore masks ongoing progression of liver damage.

Liver function and health is intensively monitored in all co-infected people. This helps people with HIV and hepatitis C and their doctors make decisions about treatment and care.

For more information on HIV and hepatitis C, read or download our HIV & hepatitis booklet.