Late testing rates declining in Europe, but largely in gay men

Over Europe as a whole, the proportion of people testing late for HIV decreased between 2002 and 2010, a presentation at the 14th European AIDS Conference in Brussels last week showed, and the average CD4 count on diagnosis increased. However, these changes have mainly been seen in gay men; heterosexual people and, especially, older people are still much more likely than average not to be diagnosed until they have a low CD4 count or are even sick with AIDS-related conditions.  

Late presentation in Europe: the SPREAD study

Marije Hofstra of the European Society for translational Antiviral Research introduced the SPREAD project, which monitors HIV testing in 30 European countries from Ireland to Russia (in the EU, only the UK, France and Hungary are not members). It uses an algorithm to collect a representative sample of the European diagnosed population – in this case, a sample of 8048 people.

She first defined ‘late presenter’. Ideally late presentation should be defined by the period of time between infection and diagnosis, but as this is hard to establish, it is usually defined by a surrogate marker – the CD4 count at time of diagnosis. Hofstra used three overlapping definitions of a late presenter: first, a CD4 count under 350 cells/mm³ at diagnosis; secondly, a CD4 count under 200 cells/mm³; and thirdly presenting with AIDS-related symptoms at any CD4 count. Using these definitions will catch some ‘fast progressors’ who develop low counts soon after infection, and Hofstra estimated from other surveillance figures that 27% of patients with CD4 counts under 350 cells/mm³ in Europe have in fact been infected for less than a year, 7% with CD4 counts under 200 cells/mm³ and 2.5% with AIDS, totalling 1422 patients.

Excluding all participants who had been positive for less than a year resulted in a database of 6266 participants. Of these, 80% were male, 53% gay men, 34% heterosexual and 6% injecting drug users. Their average age was 37. Fifty-six per cent were born in western Europe, 20% in eastern Europe and 9% in sub-Saharan Africa. The average CD4 count on diagnosis in the whole patient sample was 392 cells/mm³ and their viral load 63,000 copies/ml.

Of this group, 55% satisfied the widest definition of being a late presenter between the years 2002 and 2005: by 2008 to 2010, this had reduced to 48%. The proportion with CD4 counts under 200 cells/mm³ had shrunk from 34 to 27% and who had AIDS upon diagnosis from 16 to 12%.

Gay men were less likely to be late presenters throughout: the proportion with CD4 counts below 350 shrank from 45 to 39% over the 2002 to 2010 time period, while in heterosexuals it went down from 66 to 61%. However, while the proportion of gay men diagnosed with AIDS halved from 12 to 6%, it did not decrease in either heterosexuals or drug users; in heterosexuals 17 to 18% had an AIDS-related condition when diagnosed throughout the time period, and in drug users it actually went up, varying non-significantly between 12 and 16%. In multivariate analysis, heterosexuals were 2.14 and injecting drug user 2.21 times more likely to be diagnosed late than gay men.

There was a slight, but significant, tendency for people from central and eastern Europe to be diagnosed late (28% more than in western Europe), and immigrants in all areas were 62% more likely to be diagnosed late.  

The biggest single risk factor, though, was age. People over 50, throughout Europe, were 2.55 times more likely to be diagnosed late than others; between 2008 and 2010, 68% of over-50s were diagnosed with a CD4 count under 350 cells/mm³, 49% under 200 cells/mm³ and 25% with AIDS. Although this proportion had declined since the 2002 to 2005 period, it had not done so significantly. The researchers emphasised the importance of aiming testing programmes at women, people who inject drugs, migrants and, especially, older people.