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NAM aidsmap

18th Conference on Retroviruses and Opportunistic Infections, Boston, 27 February-2 March 2011


News and conference coverage from NAM

This is our final bulletin from CROI 2011. We hope you have found our news coverage useful. You can find all our coverage at www.aidsmap.com/croi2011, including the news reports and bulletins.

We are always looking for ways of improving and developing our resources – so if you have any comments that you would like to make about this bulletin, then please get in touch, we would love to hear from you. Contact us at info@nam.org.uk.

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HIV and cardiovascular disease

Long-term infection with HIV is associated with an increased risk of thickening of the carotid artery – an important early warning sign of cardiovascular disease.

A number of studies have shown that people with HIV have an increased risk of cardiovascular diseases such as heart attack and stroke.

There’s uncertainty about the causes, but they may include the side-effects of some anti-HIV drugs, traditional risk factors such as smoking, diet, age, and the inflammatory effects of HIV infection.

However, it’s been difficult to untangle the exact causes because these risk factors are so prevalent in people with HIV.

Therefore French researchers designed a carefully controlled study that involved HIV-positive patients who were taking treatment; patients who weren’t yet on therapy; and HIV-negative people. They were well matched for other characteristics, and none smoked.

The researchers monitored thickness of the carotid artery. This gives an indication of hardening of the arteries, an important symptom of cardiovascular disease.

Thickening of this artery was strongly associated with longer duration of infection with HIV.

Another risk factor was a poor anti-inflammatory response by the immune system.

Separate US research showed that infection with HIV increases the risk of heart attack by 40% and the risk of any cardiovascular disease by 20%.

It involved almost 250,000 patients; approximately 10% were HIV-positive.

A low CD4 cell count and age both increased the risk of cardiovascular disease.

HIV prevention: treatment as prevention

Results from a large study have provided some more insights into the infectiousness of people with HIV.

Three substudies of the Partners in Prevention trial examined HIV transmission risks in over 3000 heterosexual couples where one partner is HIV-positive and the other HIV-negative (often called ‘serodiscordant’ relationships).

New findings show that the level of viral load in the blood is linked to infectiousness.

The higher a patient’s viral load, then the higher the risk of transmission.

For patients with a viral load below 1000 copies/ml, the risk of transmission per sex act was 1 in 3537.

This increased to a risk of 1 in 1220 if viral load was 10,000 copies/ml, and 1 in 434 when viral load was 100,000 copies/ml.

Findings from the study also look set to further fuel the debate about the infectiousness of people taking HIV treatment.

A few HIV transmissions originated in people who had an undetectable viral load in their genital fluids.

However, there were no transmissions when a patient had an undetectable viral load in their blood.

Preventing HIV: PrEP and microbicides

New studies suggest that two promising methods of HIV prevention could cut new infections in Africa.

Pre-exposure prophylaxis (PrEP) involves an HIV-negative person taking antiretroviral treatment to prevent them becoming infected with the virus. A study involving gay men has shown that it can cut the rate of infections.

A modelling study predicted that expanding HIV treatment in Africa could mean 700,000 fewer infections in the continent by 2022.

If PrEP was also provided, then 830,000 new infections would be prevented, and this could increase to 1.25 million if treatment reached all those who needed it, and adherence was good.

Separate research showed that microbicides have the potential to cut infection rates by a third.

Other studies examined the cost-effectiveness of PrEP.

These showed that cost-effectiveness was dependent upon the effectiveness of the treatment and the circumstances in which it was used.

In relationships where one partner was HIV-positive and the other HIV-negative, PrEP could be cost-effective if the HIV-positive partner wasn’t taking antiretroviral treatment.

Preventing mother-to-child transmission

Six months of nevirapine therapy in babies can reduce the risk of mother-to-child HIV transmission by 75% when compared to six weeks of nevirapine, research conducted in South Africa, Tanzania, Uganda and Zimbabwe has shown.

HIV can be transmitted from a mother to her baby in breast milk, so breastfeeding is not recommended for HIV-positive women in many countries. However, in resource-poor countries, formula feeding is often not a feasible or safe alternative to breastfeeding.

The large study involved 1522 babies, born to 1505 HIV-positive mothers, and who were being breast fed. None of the mothers in the study were taking HIV treatment and their babies were breast fed for six months.

They were randomised to receive extended infant nevirapine prophylaxis or a placebo after six weeks of treatment for all infants with nevirapine.

Transmission rates were significantly lower among the infants who received nevirapine. Rates of adverse events were similar between the two arms of the study.

Other research showed that infant prophylaxis that consisted of nevirapine, 3TC and AZT resulted in 50% fewer transmissions than AZT alone.

Infant HIV treatment in resource-limited settings

Studies have provided some insights into the role of nevirapine in infant HIV therapy in poorer countries. Current World Health Organization (WHO) guidelines recommend lopinavir/ritonavir for infants exposed to nevirapine around the time of birth, and nevirapine for the rest.

One study showed that treatment based on lopinavir/ritonavir had some advantages over therapy that included nevirapine.

Viral load was more likely to be suppressed with lopinavir/ritonavir treatment; furthermore rates of discontinuation were lower, and there were also fewer deaths.

However, nevirapine was associated with bigger increases in CD4 cell count and better growth.

WHO guidelines are likely to be reviewed in the light of these findings.

Another study looked at the best way to use treatment in infants who had been infected with HIV despite being given a single dose of nevirapine to prevent transmission.

This study found that starting with lopinavir/ritonavir and then switching to nevirapine could be made effective if viral load testing was carried out six and twelve months after switching – this identified all cases of failure.

HIV treatments directory

The HIV treatments directory is your guide to all medical aspects of HIV & AIDS. An invaluable reference resource to complement your current expertise, the directory is a perfect aid to support you and your staff working in the HIV sector.

Contents include:

  • Comprehensive information on illnesses and symptoms, starting and changing treatment, side-effects and drug interactions
  • A to Z of antiretroviral drugs
  • Full reference details for thousands of original drug trials and studies

Be the first to receive the brand new edition for 2011 and pre-order your copy today for a discounted price of £58 (usual price £64.95). Just email info@nam.org.uk with your delivery address and credit/debit card details or call us on +44 (0)20 7837 6988 and quote offer code T69.

Please note: orders to Europe will incur £5 postage, all other countries £10 postage.

To limit credit control issues we regret that we cannot invoice organisations outside the UK

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