New HIV diagnoses among adults aged 50 years or older in 31 European countries, 2004–15: an analysis of surveillance data

Background The HIV burden is increasing in older adults in the European Union (EU) and European Economic Area (EEA). We investigated factors associated with HIV diagnosis in older adults in the 31 EU/EEA countries during a 12 year period. Methods In this analysis of surveillance data, we compared data from older people (aged ≥50 years) with those from younger people (aged 15–49 years). We extracted new HIV diagnoses reported to the European Surveillance System between Jan 1, 2004, and Dec 31, 2015, and stratified them by age, sex, migration status, transmission route, and CD4 cell count. We defined late diagnosis as CD4 count of less than 350 cells per μL at diagnosis and diagnosis with advanced HIV disease as less than 200 cells per μL. We compared the two age groups with the χ2 test for difference, and used linear regression analysis to assess temporal trends. Findings During the study period 54 102 new HIV diagnoses were reported in older adults. The average notification rate of new diagnoses was 2·6 per 100 000 population across the whole 12 year period, which significantly increased over time (annual average change [AAC] 2·1%, 95% CI 1·1–3·1; p=0·0009). Notification rates for new HIV diagnoses in older adults increased significantly in 16 countries in 2004–15, clustering in central and eastern EU/EEA countries. In 2015, compared with younger adults, older individuals were more likely to originate from the reporting country, to have acquired HIV via heterosexual contact, and to present late (p