Re‐assessing the late HIV diagnosis surveillance definition in the era of increased and frequent testing

Abstract

Objectives Late HIV diagnosis (CD4<350 cells/mm 3 ) is a key public health metric. In an era of more frequent testing there is greater likelihood of HIV diagnosis occurring during seroconversion, when CD4 counts may dip below 350. We apply a correction, considering markers of recent infection and reassess one-year mortality following late diagnosis. Methods We used national epidemiological and laboratory surveillance data on all persons diagnosed with HIV in England, Wales, and Northern Ireland (EW&NI). Persons with a baseline CD4<350 were reclassified as “not-late” if they had evidence of recent infection (recency test and/or negative test within 24 months). A correction factor (CF) was the number reclassified divided by the number with CD4<350. Results Of the 32,227 people diagnosed with HIV in EW&NI between 2011-2019 with a baseline CD4 (81% of total), 46% had a CD4<350 (uncorrected late diagnosis rate): 34% of gay and bisexual men (GBM), 65% of heterosexual men, and 56% of heterosexual women. Accounting for recency test and/or prior negative tests gave a “corrected” late diagnosis rate of 39% and corresponding CF of 14%. The CF increased from 10% to 18% during 2011-2015, then plateaued, and was larger among GBM (25%) than heterosexual men and women (6% and 7%, respectively). One-year mortality among persons diagnosed late was 329 per 10,000 after reclassification (an increase from 288/10,000). Conclusions The case-surveillance definition of late diagnosis increasingly over-estimates late presentation, the extent of which differs by key populations. Adjustment of late diagnosis is recommended, particularly for frequent testers such as GBM.

Late diagnosis of HIV in 2022: Why so little change?

“…This showed that roughly 75% of late diagnoses in 2020 were actually diagnosed ‘very late’ with a CD4 count <200 cells/mm 3 . This includes people who are hospitalized with opportunistic infections, some with CD4 counts <50 copies/mL [7, 8].…”

Late diagnosis of HIV: An updated consensus definition

“…It is also known that most people who are seroconverting recover their CD4 count within a year [ 13 ], typically within 6 months, and those who do not could rather be considered as ‘fast progressors’ [ 6 , 14 , 15 ]. Furthermore, research from the UK and Sweden shows that among people newly diagnosed with HIV with a negative test recorded, the vast majority had their last negative test within the last 12 months, so lengthening the cut‐off would have minimal effect [ 9 , 16 ]. The 12‐month cut‐off was endorsed by members of the EACS Governing Board and antiretroviral therapy (ART) panel group.…”

“…The EuroTEST Initiative convened a working group of experts in HIV from Europe, including clinicians, epidemiologists, public health professionals and civil society, to review the existing late HIV diagnosis definition in January 2022. Multiple meetings were held for stakeholders to discuss possible updates to the definition based on previous research [ 7 , 8 , 9 ]. The full list of experts consulted can be found in Appendix S1 .…”

“…Using the current definition of late HIV presentation, these individuals are incorrectly assigned as being diagnosed late. This issue of overestimation has already been raised by research groups in Belgium [ 7 ], Sweden [ 8 ] and the UK [ 9 ]. This has led to correction factors being applied to the late diagnosis rate of specific subgroups.…”

Late HIV diagnosis: Where we stand and the way forward

“…Exclusion of recent infections from population‐ level analyses allowed researchers to correct the total number of late‐diagnosed cases to obtain more precise data. Such reclassification was successfully applied in the study by Kirwan et al, and allowed the calculated late diagnosis rate to be decreased by the overall factor of 14% [9]. The correction rates accounting for recent infection were highest among extensively tested populations (e.g.…”