Drugs for prevention

Studies have shown that the drugs used to treat people with HIV soon after they are diagnosed also make them less infectious. A breakthrough trial involving more than 1,700 couples where one partner had HIV and the other did not, published in May last year, found a 96% reduction in infection of the healthy partner.

PrEP

The US authorities have this week licensed an antiretroviral drug called Truvada for pre-exposure prophylaxis (PrEP). This means it can be taken daily by a healthy person to protect him or herself against infection by a partner with HIV. There are concerns however over side-effects and possible development of resistance if the drug is not taken consistently and under medical supervision.

Circumcision

This has been shown to decrease infections among men, but uptake is not as fast across the regions worst hit by Aids as experts would like.

Home testing kits

The US has also licensed the first home testing kit for HIV. It works on a saliva swab and gives a result within around 20 to 40 minutes. Advocacy groups believe it would help those who are reluctant to go to a clinic but know they are at risk to find out about their HIV status. Around one in five Americans with HIV and a quarter of those in the UK do not know they have the virus.

CD4 count pinprick

New testing and diagnostics devices suitable for the developing world have been invented. The latest is a simple device which uses a dipstick test to assess a person's CD4 count – a measure of the strength of their immune system which the virus erodes and therefore their need for treatment – from a pinprick drop of blood.