A new method to assign country of HIV infection among heterosexuals born abroad and diagnosed with HIV.

OBJECTIVE: To apply a new method to ascertain likely place of HIV infection among persons born abroad and diagnosed with HIV in the United Kingdom (UK).
DESIGN: Analyses of heterosexual adults born abroad, diagnosed with HIV in the UK between 2004 and 2010, and reported to the national HIV diagnoses database.
METHODS: Year of infection was ascertained by applying an estimated rate of CD4 cell count decline between an individual's CD4 cell count at diagnosis and estimates of CD4-cell count at infection. A person was classified as having probably acquired HIV while living in the UK if estimated year of infection was later than reported year of arrival in the UK.
RESULTS: Of 10 612 heterosexual adults born abroad included in the analyses, 85% (9065) were of black-African ethnicity. We estimate that 33% (26-39%) of persons acquired HIV while living in the UK. This percentage increased from 24% (16-39%) in 2004 to 46% (31-50%) in 2010 (P < 0.01). The estimate of 33% is three times higher than national estimates of HIV acquired in the UK based on clinic reports (11%) (P <  0.01).
CONCLUSION: : Assigning place of HIV infection using routinely available clinical and demographic data and estimated rates of CD4 cell decline is feasible. We report a high and increasing proportion of persons born abroad who appear to have acquired their HIV infection while living in the UK. These findings highlight the need for continued targeted HIV prevention efforts, particularly among black-African communities.