title: Comparing those diagnosed early versus late in their HIV infection: implications for public health.
abstract: Routine HIV surveillance cannot distinguish between recent and older infections: HIV-positive individuals reported soon or long after infection are both considered new diagnoses from a surveillance perspective, notwithstanding the time since infection. This lack of specificity makes it difficult to understand the jurisdiction-specific trends in HIV epidemiology needed for prevention planning. Previous efforts have been made to discern such timing of infection, but these methodologies are not easily applied in a public health setting. We wished to develop a simple protocol, using routinely collected information, to classify newly diagnosed infections as recent or older, and to enumerate and characterize recent versus older infections. Applying our methodology to a review of HIV cases reported between January 2011 and December 2014, we classified 62% of cases; one-third of these were recent infections. Although men who have sex with men (MSM) and persons from HIV-endemic countries (HEC) disproportionally accounted for new HIV diagnoses, the dynamics of HIV transmission within these groups differed dramatically: MSM accounted for the majority of recent infections, whereas persons from HEC accounted for the majority of older infections. Among older infections, one-quarter were previously unaware of their infection. Categorizing cases in this manner yielded greater, jurisdiction-specific understanding of HIV, and guides subpopulation-specific interventions.
authors.affiliation: 1 Epidemiology Unit, Ottawa Public Health, Ottawa, ON Canada.
authors.forename: Dara
authors.initials: D
authors.lastname: Spatz Friedman
authors.affiliation: 2 Faculty of Health Sciences, School of Nursing, University of Ottawa, Ottawa, ON Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: O'Byrne
authors.affiliation: 3 Healthy Sexuality and Risk Reduction Unit, Ottawa Public Health, Ottawa, ON Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Roy
mesh_terms: D000328:Adult; D057210:Delayed Diagnosis; D042241:Early Diagnosis; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D006801:Humans; D008297:Male; D009864:Ontario; D011634:Public Health
keywords: Diagnosis; HIV; epidemiology