Sex doesn't end at 50 – whatever teenagers assume– and neither does the risk of HIV infection. Research published last week at the International Aids conference in Vienna by the UK's Health Protection Agency shows that HIV rates are increasing among people of middle age. The numbers being diagnosed each year more than doubled between 2000 and 2007.
The actual figures may look small – 299 new diagnoses in 2000 and 710 in 2007 – but it is the trend that worries the experts. It's the same in the United States; the proportion of people over 50 among the newly diagnosed has risen from 17% in 2001 to 29% now.
There are two distinct groups of people within the UK figures. About half have had HIV for years without knowing it, but the other half acquired it only recently.
Some of those who have had it for years will have had no idea until they started to get sick. Unfortunately, some of them arrive when their immune system has been so eroded that they have full-blown Aids. The prognosis for them is not so good. Others will not have wanted to go for a test, even though they might know their sexual behaviour puts them at risk. This is unfortunate, because modern antiretroviral drugs that suppress the virus allow people to live long and healthy lives and their own infectivity drops to near zero, so their partners are safer.
But there seems little doubt that changing sexual behaviour among the over-50s is also a factor in these rising HIV rates. "We are seeing a lot more partner changes than in the past," said Dr Valerie Delpech of the Health Protection Agency. "There is a greater rate of divorces and new relationships."
The 50-plus divorcee does not necessarily think of protecting him or herself from HIV when launching into a new relationship, perhaps after years of marriage. In the past, they may not have thought sexual health warnings had any relevance to them.
"But now they are back into discovering new sexual relationships," said Delpech. "This is a really clear message. If you are starting a new relationship, use a condom until both of you have been tested for HIV and sexually-transmitted infections."
She acknowledges this will be a difficult conversation, but points out that the word has got through to 80% of men who have sex with men, who now say they use a condom with a casual partner.
A number of white, middle-aged men became infected abroad, particularly in Asia. There are messages to be learned about taking the same precautions abroad as you would at home, said Delpech – but also darker issues around sex tourism.
