HIV‐associated neurocognitive disorders (HAND) in a cART‐treated cohort of adults aged 50 and over in Kilimanjaro, Tanzania: The first longitudinal follow‐up study of HAND in an older population in sub‐Saharan Africa

Abstract

AbstractBackgroundHIV‐associated neurocognitive disorders (HAND) are highly prevalent in Sub‐Saharan Africa (SSA), due to increasing life expectancy and availability of combination antiretroviral therapy (cART). These preliminary data represent the first longitudinal study of HAND in older cART‐treated adults in SSA with the aim of reporting prevalence and persistence of cognitive impairment, and neurocognitive profile.MethodWe investigated prevalence and incidence of HAND diagnosis and subtypes (asymptomatic neurocognitive impairment (ANI), minor neurocognitive disorder (MND) and HIV‐associated dementia (HAD), alongside neuropsychological profile and neurological symptom burden over 40 months in 253 HIV positive adults aged ≥50 attending a government clinic (2016‐2019). HAND diagnoses were reviewed annually by a consensus panel using Frascati criteria, based on detailed clinical assessment.ResultAt baseline (2016), 253 individuals underwent full assessment, of these, 185 were re‐evaluated in 2017, 181 in 2018 and 128 in 2019. 139 individuals had complete data 2016 ‐2018. The majority (68%) were female, median age at diagnosis was 51, and time since diagnosis 7.6 years. Almost all were receiving cART and were well‐managed (mn CD4 532.76. HAND prevalence was 47% in 2016 (n=253, 95.5% cART‐treated) and 49% in 2017 (one‐year incidence from those at risk 37%). Provisional follow‐up data indicates HAND prevalence of 62% in 2018 (n=172) and 54% in 2019 (n=128). Milder forms of HAND predominated, with evidence of reversibility. The predominant cognitive domains affected were both cortical and subcortical (executive function, motor speed, working memory, verbal memory (word list learning) and orientation) with visuoconstruction and language comprehension relatively spared. Both depression and neurological impairments were highly prevalent.ConclusionThis is the first longitudinal study of neurocognitive impairment in older adults living with HIV in SSA. Findings suggest cART and regular follow‐up are insufficient to prevent occurrence or progression of HAND, though the aetiology remains unclear. Both cortical and subcortical cognitive domains are affected suggesting the possibility of non‐HIV‐related neurodegenerative cognitive decline. If replicated in other SSA settings, HAND is likely to be a major cause of cognitive impairment in older people in SSA, despite cART treatment.