Swiss Statement Impact

posted: 09/11/2010

The “Swiss Statement,” nearly three years ago, from leading HIV clinicians said that effective HIV treatment is, subject to conditions, enough to stop HIV transmission. There is now considerable evidence from a large Swiss study that while condom use has fallen, HIV infections there have not risen. This is despite the proportion of people reporting sex without a condom with their main partner increasing after the statement.
 

People believe treatment prevents transmission
“In contrast to earlier results from our cohort, …. we now observed an association of a suppressive ART [antiretroviral therapy] and unprotected sexual contacts in MSM [men who have sex with men] and heterosexual women with stable partners, indicating that some groups with HIV infection have adopted the belief that treatment of HIV infection is a sufficient HIV-prevention measure”, write the investigators.
 

Editorial alarm
An editorial in the same issue of Clinical Infectious Diseases sounds an alarm about individuals making decisions about the use of condoms based on having an undetectable viral load. The editorial points out that some HIV transmissions are thought to be from people with an undetectable viral load, and that we don’t know everything about how treatment affects infectiousness.
 

It is equally true to point out, as George House Trust does here, that people who reliably use condoms sometimes also pass on HIV. Condom accidents happen; treatment accidents happen too. And we still don’t know everything about condom use and HIV transmission either. People have the right to choose the sexual risks they take.
 

Swiss Statement
In January 2008 a group of senior HIV doctors in Switzerland published what has become known as the Swiss Statement.
This said that HIV-positive heterosexuals could stop using condoms with their regular HIV-negative partner if:

• their partner agreed
• they were taking HIV treatment
• their blood viral load had been undetectable for at least six months
• they did not have any other sexually transmitted infections.

Controversy surrounded the Swiss Statement. The Swiss Statement was followed by similar statements from French, German and USA HIV clinicians. There is a general consensus that taking HIV treatment substantially reduces the risk of sexual transmission of HIV. Nevertheless, experts believe that there remains a low risk of HIV transmission and advise the use of condoms alongside HIV treatment.

Condom use changes

The Swiss investigators wanted to see whether condom and other behaviour has changed following the statement. They analysed the self-reported condom use of 7309 patients between 2007 and 2009. They split the people into the main HIV risk groups: gay and other men who have sex with men; heterosexual men and women; and injecting drug users.
Other recent Swiss research has shown that about a quarter of gay men are using unreliable HIV risk reduction strategies such as sero-sorting (choosing partners with the same HIV status) or strategic positioning (being insertive in sex rather than receptive). They note that these methods have never been promoted in Switzerland.
 

Four out of five are undetectable
A total of 80% of patients were taking HIV treatment, and 82% of these individuals had an undetectable viral load.
 

One partner people
Most people reported sex with a single partner - 46% of gay men, 80% of heterosexual men, 91% of heterosexual women, and 75% of injecting drug users have one partner.
 

More than one
18% of gay men, 4% of heterosexual men, 1% of heterosexual women and 3% of injecting drug users said they have both regular and casual partners.
 

37% of gay men said they only had casual partners, as did 17% of heterosexual men, 8% of heterosexual women and 22% of injecting drug users.
 

Condoms
Regular condom use was reported by 89% of individuals with a regular HIV-negative partner and by 48% of those whose partner was also HIV-positive. For all four HIV risk groups (gay men, heterosexual women, etc) , rates of steady condom use were lower with regular partners than casual partners (88% vs. 92%). In other words, people were more likely to use condoms to protect casual partners than a main partner.
 

Sex without condoms rose:

• the longer the time since the Swiss Statement
• when people have an undetectable viral load (gay men, and heterosexual women with stable partners)
• among younger people
• with moderate to severe alcohol use (heterosexual women, and injecting drug users with stable partners, and heterosexual men with casual partners)
• with illicit drug use (gay men, and heterosexual women with stable partners, and gay men, and heterosexual men and women with casual partners).

Swiss Statement effect with regular partners
The investigators focused on reported condom use with regular partners. They found that even before the Swiss Statement, the proportion of gay men and heterosexual women reporting unprotected sex with stable partners was already rising. After the statement appeared, condom use fell further among people who have an undetectable viral load.
 

Gay men, heterosexual men and women whose viral load was undetectable were all significantly more likely to have unprotected sex with their main partner after the statement.
 

“The effect of the ‘Swiss Statement’ was most pronounced in groups with stable partners who had an undetectable viral load”, comment the investigators. This is not surprising. The Swiss Statement was a precise and targeted message intended for heterosexual people in stable relationships. The researchers say that people were able to accept the “complex recommendations” of the statement.
 

No rise in infections
The investigators note that the statement and these changes in sexual behaviour have not increased new HIV infections in Switzerland.
 

They conclude that “because ART influences sexual behaviour …., adherence to treatment and plasma viral load should be regularly monitored …., and counselling of couples should be advocated.
Such counselling should be individualised, and account should be taken of drug and alcohol use.
 

Editorial angst
Dr Myron Cohen, author of the editorial, says that there is “every reason to pause and reflect” about the actual impact of HIV treatment on infectiousness. “The protection provided from ART is not absolute and is not absolutely predictable”, he writes.
Cohen notes that there are many unanswered questions about the infectiousness of people taking suppressive HIV treatment. These include the risk of transmission over time; the impact of different HIV treatment combinations on infectiousness; and the risks involved with anal and vaginal sex.
 

The editorial worries about HIV transmissions, as HIV clinicians usually do. People using condoms also sometimes accidentally pass on HIV. There will never be absolute guarantees in HIV prevention. Condom accidents happen; treatment accidents happen too. People have the right to choose the sexual risks they take.

The evidence here is that Swiss women and men, gay and straight, are being sensible. There has been no reported rise in Swiss HIV infections despite less use of condoms and greater reliance on treatment for prevention. Dr Cohen should relax.
 

Source 

Source with references 

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