New diagnoses among over 50s double in England, Wales and Northern Ireland

Almost half of older patients with HIV are diagnosed late, according to a study published in the August 24^th edition of AIDS.

The study was conducted using data gathered in England, Wales and Northern Ireland between 2000 and 2007. The investigators defined older as aged 50 or above. The number of adults in this age bracket living with HIV in these countries tripled in this time period, and new diagnoses doubled. Moreover, almost half of older adults who were newly diagnosed with HIV acquired their infection when they were aged over 50.

“Adults aged 50 years and over account for a significant number of persons living with HIV in developed countries and it is important that global and national surveillance outputs include older age groups,” write the investigators.

A separate study published in HIV Medicine demonstrated that the proportion of new HIV diagnoses involving older adults in Europe differed according to geographical region. The paper also outlined the burdens that living with HIV in older age can entail.

HIV in older adults in England, Wales and Northern Ireland

Between 1997 and 2007 there was a three-fold increase in the number of people living with HIV in the UK. During this period there was also a sharp rise in the number of older adults living with the infection.

However, it is unclear whether this increase is because patients with HIV are living longer because of antiretroviral therapy, or due to an increase in new HIV diagnoses in this age group.

In order to gain a better understanding of this issue, researchers from the Health Protection Agency analysed surveillance data gathered between 2000 and 2007.

This showed that adults aged 50 and over accounted for 8% of all new HIV diagnosis between 2000 and 2007.

However, this increased from 8% of new diagnoses in 2000 to 9% in 2007. In addition, the absolute number of older patients newly diagnosed with HIV more than doubled from 299 in 2000 to 710 in 2010. The median age at the time of diagnosis was 55. Almost three-quarters of new diagnoses in this older age group involved individuals aged between 50 and 59.

Gay and other men who have sex with men accounted for 40% of diagnoses in the over 50s. A third of new diagnoses were in heterosexual men, and 25% involved heterosexual women.

Almost all (94%) of older gay men were of white ethnicity. Compared to younger heterosexual men diagnosed with HIV, older patients were more likely to be of white ethnicity (25 vs 14%) and to report their probable region of infection as Asia (18 vs 6%). Older women diagnosed with HIV were also more likely than the under 50s to be of white ethnicity (21 vs 9%).

A total of 8255 older adults accessed HIV care between 2000 and 2007. These individuals represented 16% of all HIV-positive patients seen in this period.

Between 2000 and 2007, AIDS was diagnosed in 20% of older adults. Most (91%) of these diagnoses were made within three months of diagnosis with HIV. During this same time period, only 10% of younger patients with diagnosed with HIV, but like the older patients, 90% of these diagnoses were made soon after the initial HIV diagnosis.

The investigators defined late HIV diagnosis as a CD4 cell count of below 200 cells/mm³ at the time of diagnosis. Older patients were more likely than younger patients to have a CD4 cell count below this level at the time of their diagnosis (48 vs 33%, p < 0.001).

A total of 538 (13%) older patients died between 2000 and 2007. Older patients diagnosed with a CD4 cell count below 200 cells/mm³ were 14 times more likely to die than younger patients who had a CD4 cell count below this threshold at the time of their diagnosis (14 vs 1%, p < 0.001).

Moreover, older patients diagnosed late were approximately two and a half times more likely to die within a year of diagnosis than younger patients who were diagnosed with a CD4 cell count below 200 cells/mm³.

The overall mortality rate amongst older patients was 25 per 1000 person-years. In contrast, the mortality rate for younger patients was 12 per 1000 person-years.

Based on CD4 cell count at the time of diagnosis, the investigators calculated that 48% of older patients were infected with HIV when they were aged 50 and over. The proportion of patients infected with HIV in older age remained stable over the period of the study.

Three-quarters of individuals aged over 50 at the time of their infection were men, and 54% were gay men.

HIV amongst older adults in Europe

In separate research, investigators used World Health Organization data to estimate the proportion of new HIV diagnoses involving older patients in western, central and eastern Europe.

Their analysis showed that in 2007 a total of 13% of new diagnoses in western Europe involved patients aged 50 and above. The figures for central and eastern Europe were 10% and 3% respectively.

The researchers also outlined some of the issues that an HIV diagnosis involves for older patients. These included:

• Stigma related to both HIV and older age.

• The diseases of ageing and their synergy with HIV.

• Lack of targeted prevention resources.