Psst! The latest on TasP

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Post by David Menadue30 Nov 2013


Treatment as prevention (TasP) describes HIV prevention methods that use antiretrovirals (ARVs) to decrease the risk of HIV transmission.1 The concept grew out of the 2011 results of the HPTN 052 study, conducted largely in heterosexual serodiscordant couples, which showed that being on treatment reduced the risk of passing on HIV by 96%.

There are studies underway, including Opposites Attract in Australia, to determine the relative risks for serodiscordant gay male couples; but it is thought from small trials conducted so far that the rates may be similar.

A Pre-Exposure Prophylaxis (PrEP) study called iPREX also showed that HIV-negative people could avoid contracting HIV by taking ARVs themselves.

In November 2012 all the peak national HIV organisations in Australia signed onto The Melbourne Declaration calling on government to support a range of treatment as prevention approaches to reach UNAIDS targets of reducing HIV transmissions globally.2

To do this, Australia agrees to embrace three pillars of treatment as prevention: greater access to HIV testing (including rapid testing), earlier access to antiretroviral treatment for people with HIV, and making PrEP available for those at high risk. There has been some success in getting governments to support the measures. In August 2013, the federal government signed up to work towards the target of reducing HIV infections by 50% by 2015.

The NSW government has built its recent HIV Strategy around achieving these goals. However, the recent 10% increase in national HIV cases (the largest rise in 20 years) does not augur well.


There is a growing base of research evidence that treating earlier can reduce the amount of latent HIV held in reservoirs, reduces the amount of inflammation that HIV causes in the body, and may prevent the development of other comorbidities (such as heart disease, cancer and osteopenia) down the track.

Several campaigns have encouraged people with HIV to consider treating earlier.

NAPWHA’s ‘Start the conversation today’ campaign told people that things are different now and to consult their doctor about the changes.

This campaign had an effect on Chris (see his story below) who had just been diagnosed when the ads came out. He talked to his doctor who told him that he did not qualify for treatment, even though he had an HIV-negative partner. 

More recently, ACON launched the ‘Ending HIV’ campaign, with earlier treatment as one of its key messages. According to principal planner Yves Calmette, the campaign has had the greatest visibility of any campaign by the organisation in recent times.

"People are taken by the idea that we can end HIV," he told me. "Many did not believe it before the campaign but were more convinced after watching the video on our website and reading supporting information," Yves says.

ACON’s evaluation did show less understanding about the role of treatments in turning around the epidemic. Nearly 600 people filled in the online survey on the campaign, most of whom were HIV-negative young gay men.

While they understood the value of getting testing regularly, few were sure about whether having an undetectable viral load would help prevent HIV.

"We would like HIV-positive and negative guys to understand these issues and make considered judgments about the implications of this in their sex lives," says Yves.

The ‘Ending HIV’ campaign has been adopted by NSW Health and is currently being run out elsewhere along the eastern seaboard.


One of our biggest impediments to achieving a major reduction in HIV diagnoses is that a significant number of sexually active positive men don’t know they have HIV.

The 2010 Gay Community Periodical Study estimates that the number of gay men not testing regularly is around 13% of the gay male population; although other research suggests this may be considerably higher.3

The licensing of rapid tests will hopefully improve this. ACON and the Victorian AIDS Council has set up community-run facilities, which operate after hours, and a number of GP practices around the country have set up rapid testing facilities as well. Rapid testing means better access with results given in just 30 minutes.

"We’ve been surprised and delighted with the rapid uptake of a [test]," says Michael Badorrek from ACON. The numbers they are seeing has exceeded expectations, particularly those who have never tested for HIV before.

"Clients rate the convenience of the location in Surry Hills, the availability of same-visit results and a more relaxed clinical environment in a service staffed by guys like them as their top three reasons for visiting the site," says Michael.


One of the more controversial pillars of treatment as prevention is the use of PrEP.

Analysis of the iPREX data suggests that PrEP may be as much as 99% effective if taken seven days a week, or 96% effective if taken four times a week.4

The Victorian government approved funding for Monash University and Alfred Health to trial PrEP in Melbourne. Truvada will be offered to participants considered at risk of acquiring HIV. Half of the 200 participants who agree to take Truvada over 12 months will be compared to the half who declined to take it.

This form of access trial will help us formulate a much-needed PrEP strategy in Australia.


The more unprotected casual sex you have the greater the risk of picking up sexually transmitted infections (STIs), such as gonorrhoea or syphilis. STIs increase a positive person’s viral load, making them more likely to transmit the virus and can make a negative person more vulnerable to infection.

This is why it is still so important to use condoms in casual sex situations. They are still the safest bet for people in regular relationships, too.


Chris is a 35-year-old gay man who was diagnosed with HIV in October last year. At his first test he had a CD4 count of over 900 but a viral load of 444,000. He did his research, spoke to the treatment officer at his local HIV organisation and decided he wanted to go on treatment as soon as possible.

"I saw a local campaign saying that if you wanted to treat HIV to talk to your doctor," Chris told me. He tried three doctors before anyone would give him treatments.

"They argued that it was too early and my case didn’t fit with the current guidelines. One doctor asked why I would want to put up with the treatment side effects. Having read up on the subject I knew the latest drugs have hardly any side effects so I felt I knew more than the doctor."

Chris didn’t want to continue with such a high viral load and felt the virus was doing him damage at those levels. He also had an HIV-negative partner and didn’t want to put him at risk.

Eventually Chris found an enlightened doctor but during the wait his CD4s had dropped to below 500.

He is grateful to be taking his Kaletra and Truvada and doesn’t find taking pills every day a burden.

"Unlike some friends who are putting off treatment as long as they can, I think being on treatment gives me freedom from worry, and happiness in the knowledge that I am not going to die."

Phil regards himself as a sexually adventurous man. He spends a lot of time on sex chat sites and is a regular at a range of sex parties that are advertised on these sites.

"As an HIV-positive man I have to tread carefully with sex in some of these situations. You can go to a party which is advertised for poz men only and find a range of negative guys there. I don’t want to be responsible for infecting anyone else but having a conversation with everyone you meet before sex is also difficult.

"While I am undetectable and not highly infectious I will usually ask about someone’s status before any unprotected sex happens. I don’t want that on my conscience. Some people say you can tell when another person is also positive, but I have been surprised when some of my assumptions were wrong.

"I get regular check-ups from my GP for sexually transmitted infections. It is easy to catch these if you have a lot of sex, whether it is unprotected or not. I know that having an STI makes your viral load go up and I don’t want to share any bugs with other people if I can avoid it."

Phil thinks there needs to be special ‘treatment as prevention’ messages targeted at HIV-positive men like him.

"I am particularly concerned about positive guys who are not on treatments and probably have a very high viral load .They can spread HIV so easily, particularly if they are having unprotected sex with people of unknown status. We all need to do our bit to prevent transmissions."

Julie has been positive for 11 years.

"At first the trauma of my diagnosis and the sense of shame I had about picking up the virus made me a real hermit. I broke off a relationship with my boyfriend at the time, giving him some dumb excuse as to why I didn’t want to see him anymore.

"Then I got to meet a few other HIV-positive women through a peer support group and I was surprised that a lot of them have regular relationships with negative men.

"'Aren’t you afraid of passing on the virus to them?' I asked and was told about treatment as prevention and how taking treatments had reduced infectivity to such low levels that it really reduced the risks of transmission.

"Most of the women still got their partners to use condoms but if there were any issues with condom breakages or occasional slip-ups in their safe-sex routines, they were less worried than they used to be.

"So after that I decided to start dating again. I joined an online dating site and I was surprised that I got very few rejections when I would finally tell someone I was HIV positive. Once I explained what it all meant, I have had some successful dates, including one guy who I have been seeing for three months now."

    2. See
    3. Holt M et al, Gay Community Periodic Surveys National Report 2010, Sydney, Australia, National Centre in HIV Social Research, National Centre in HIV Epidemiology and Clinical Research, UNSW, 2010
    4. Grant RM et al, Pre-exposure chemoprophylaxis for HIV prevention in men who have sex with men, New england Journal of Medicine, 2010, 363:2587-259