As the latest sexually transmitted infection figures are released by the Health Protection Agency, Ford Hickson looks at the big picture concerning HIV.
People living with HIV in Britain
There are now about 50,000 people living with HIV in Britain, almost a third of who have not yet had their infection diagnosed.
The number of people living in Britain with HIV is increasing every year because more people are joining this group than are leaving it.
People join the group in two ways: people with
HIV migrate to Britain from abroad (imported infections); and people living in Britain pick up HIV (domestic infections).
Both of these ways into the HIV positive population of Britain have been increasing in recent years.
Because HIV is still incurable, people only leave the group by moving away from Britain or by dying.
Because of advances in treatment, the number of people dying from HIV has gone down dramatically in recent years and so fewer people are leaving Britain's HIV positive population.
About 3% of people living with HIV in Britain are children under 15 years of age, equally split between boys and girls. Of the adults, 70% are men.
The two communities that are bearing the brunt of HIV in Britain are the gay community and the African community.
Although only about 1% of the total population of Britain are adult gay men, almost half of the people living with HIV are gay men.
This means gay men are about 90 times more likely to be living with HIV than other people.
Similarly, although African people account for about 1% of the population in Britain, 33% of the people living with HIV are African.
This means African people in Britain are about 50
times more likely to be living with HIV than other ethnic groups.
New diagnoses of imported infections
HIV surveillance systems in Britain only distinguish imported from domestic infections if the route of transmission was
sex between women and men.
This means we are underestimating the number of
migratory infections by treating all infections in gay men and drug users as domestic.
Even so, the number of diagnoses of imported HIV has increased dramatically over recent years.
Over half of the people diagnosed with HIV last year
had moved here with the virus, predominantly from Africa.
The specific countries people with HIV migrate from suggests that civil unrest and displacement are driving people from their homes, not simply that life in Britain is attracting them.
The largest contributor to the recent increase in Britain has been Zimbabwe, a country in economic and political turmoil with a very high HIV prevalence (about a third of the population are HIV positive) and a very high rate of emigration (more than a quarter of
Zimbabwean nationals now live abroad).
New diagnoses of domestic infections
Diagnoses of domestic HIV infections have also been increasing since 2000, after a slow decline throughout the 1990s.
However, an analysis of the figures shows in last three years there have been more diagnoses of imported than domestic infections.
If we look at how domestic infections are acquired we see that the largest group continues to be gay and bisexual men, and that diagnoses among them have
increased over the last few years.
Although far fewer infections are heterosexually
acquired in Britain, these have also increased.
Only infections acquired through sharing injecting equipment have declined in the last ten years.
Sexually acquired infections are increasing among men who have sex with men, among women who have sex with men and among men who have sex with women.
All HIV transmission involve someone with HIV and someone without it.
The people who will be involved in sexual HIV transmission next year will be people with HIV and the people who have sex with them.
The majority of people with HIV in Britain are gay or African or both.
The majority of people who will have sex with them will be gay or African or both.
It is clear that unless we focus our efforts on the needs of gay men and Africans in Britain, we have little hope of reducing this national crisis.