HIV Weekly - 15th August 2012

Money problems lead to poor adherence

Australian researchers have found that having money problems can mean that people interrupt or stop their HIV treatment, or have difficulties travelling to clinic appointments.

For HIV treatment to work properly it needs to be taken correctly. Taking your treatment correctly is often called adherence. The best results are seen in people who take all or nearly all of their treatment doses at the right time and in the right way.

Research conducted in some poorer countries has shown that not having enough money to travel to clinic appointments or to pay for medicines is associated with poor adherence to treatment.

Researchers wanted to see if this was also the case in Australia, a richer country.

Anyone resident in Australia makes a contribution to the cost of their medication. This is called a co-payment and is equal to about 17% of the cost of medication. However, the amount someone has to pay in any one year is capped.

Researchers investigated whether not having enough money to meet these co-payments was linked to interrupting or stopping HIV treatment.

Their research involved 335 patients. Approximately a fifth said they found it difficult to pay for their medication and 6% reported that they didn’t have enough money to travel to the clinic.

Some 14% of participants said they had delayed purchasing treatment because of pharmacy costs and 9% reported that these costs had caused them to stop treatment.

Of those having difficulty paying for treatment or travel, 29% stopped treatment – compared to 4% of people without financial difficulties.

The researchers therefore recommend that routine clinic visits should involve questions about financial worries.

In the UK, if you are entitled to free NHS care, your HIV medication will be dispensed free of charge. If you are on benefits or a low income, help may also be available with the costs of travel for your clinic appointments.

Treatment as prevention

Two new studies have shown that very few new HIV infections originate in people who are taking antiretroviral therapy.

There is a lot of interest in the impact of HIV treatment on infectiousness. Research conducted in heterosexual couples in Africa showed that HIV treatment that reduces viral load to undetectable levels reduces the risk of transmission by 96%.

However, there are ongoing HIV epidemics in many parts of the world and rates of new infections among gay men remain especially high.

Some researchers think this could be because a large number of infections originate in people who have very recently become infected with HIV. These individuals are often unaware that they have HIV and therefore aren’t taking HIV treatment.  

Doctors in Geneva wanted to see if this was the case. They looked at the genetic structure of HIV in blood samples taken from over 1000 people diagnosed before 2000 and in 780 samples taken from people diagnosed between 2000 and 2010. This allowed them to identify linked clusters of transmissions.

Only 2% of people diagnosed before 2000 could be linked to transmissions that occurred between 2008 and 2010. Most of the participants (84%) diagnosed before 2000 were taking HIV treatment and 50% had an undetectable viral load.

In contrast, two-thirds of people who were diagnosed between 2008 and 2010 could be linked to other transmissions that occurred in that period.

“We show that the epidemic is only marginally fed by individuals diagnosed over a decade ago,” comment the researchers. “This may be related to their lower viral load as a consequence of HAART coverage… by contrast, recently infected, untreated individuals are a frequent source of new infections in Geneva.”

In separate research, Dutch investigators found that high rates of risky sex among gay men with undiagnosed HIV infection were sustaining the HIV epidemic and cancelling out the benefits of treatment on infectiousness.

Researchers developed a mathematical model to track the dynamics of the HIV epidemic in gay men between 1980 and 2009. This was matched with information obtained from gay men enrolled in a large cohort study that tracked sexual behaviour and rates of HIV diagnoses.

The researchers found that there was a reduction of risk between the mid-1980s and mid-1990s. This limited the spread of HIV.

However, the rate of new infections then increased. This was due to higher rates of unprotected sex involving men with undiagnosed HIV infection.

“The increase in risk behaviour among untreated individuals is offsetting benefits in terms of reduced incidence offered by enhanced testing and treatment, which reduce transmission,” comment the investigators. 

Other research showed that increased testing and use of HIV treatment will not be enough to contain the HIV epidemic in China.

Researchers modelled the impact of various approaches to prevention on the likely course of the HIV epidemic in China until 2040. They found that increased testing and use of treatment would prevent large numbers of new infections.

However, a combination approach to prevention that also included harm-reduction programmes targeted at high-risk populations was shown to have the biggest likely impact on the future course of the epidemic.