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Abstract

OceanStore is a utility infrastructure designed to span the globe and provide continuous access to persistent information. Since this infrastructure is comprised of untrusted servers, data is protected through redundancy and cryptographic techniques. To improve performance, data is allowed to be cached anywhere, anytime. Additionally, monitoring of usage patterns allows adaptation to regional outages and denial of service attacks; monitoring also enhances performance through pro-active movement of data. A prototype implementation is currently under development.

Objectives HIV‐associated neurocognitive disorder (HAND), although prevalent, remains a poorly researched cause of morbidity particularly in sub‐Saharan Africa (SSA). We aimed to explore the risk factors for HAND in people aged 50 and over under regular follow‐up at a government HIV clinic in Tanzania. Methods HIV‐positive adults aged 50 years and over were approached for recruitment at a routine HIV clinic appointment over a 4‐month period. A diagnostic assessment for HAND was implemented, including a full medical/neurological assessment and a collateral history from a relative. We investigated potential risk factors using a structured questionnaire and by examination of clinic records. Results Of the cohort (n = 253), 183 (72.3%) were female and the median age was 57 years. Fifty‐five individuals (21.7%) met the criteria for symptomatic HAND. Participants were at a greater risk of having symptomatic HAND if they lived alone [odds ratio (OR) = 2.566, P = .015], were illiterate (OR 3.171, P = .003) or older at the time of HIV diagnosis (OR = 1.057, P = .015). Age was correlated with symptomatic HAND in univariate, but not multivariate analysis. Conclusions In this setting, HIV‐specific factors, such as nadir CD4 count, were not related to symptomatic HAND. The “legacy theory” of early central nervous system damage prior to initiation of anti‐retroviral therapy initiation may contribute, only in part, to a multifactorial aetiology of HAND in older people. Social isolation and illiteracy were associated with symptomatic HAND, suggesting greater cognitive reserve might be protective.

Objectives: HIV-associated neurocognitive disorders (HANDs) are prevalent in older people living with HIV (PLWH) worldwide. HAND prevalence and incidence studies of the newly emergent population of combination antiretroviral therapy (cART)-treated older PLWH in sub-Saharan Africa are currently lacking. We aimed to estimate HAND prevalence and incidence using robust measures in stable, cART-treated older adults under long-term follow-up in Tanzania and report cognitive comorbidities. Design: Longitudinal study Participants: A systematic sample of consenting HIV-positive adults aged ≥50 years attending routine clinical care at an HIV Care and Treatment Centre during March–May 2016 and followed up March–May 2017. Measurements: HAND by consensus panel Frascati criteria based on detailed locally normed low-literacy neuropsychological battery, structured neuropsychiatric clinical assessment, and collateral history. Demographic and etiological factors by self-report and clinical records. Results: In this cohort (n = 253, 72.3% female, median age 57), HAND prevalence was 47.0% (95% CI 40.9–53.2, n = 119) despite well-managed HIV disease (Mn CD4 516 (98-1719), 95.5% on cART). Of these, 64 (25.3%) were asymptomatic neurocognitive impairment, 46 (18.2%) mild neurocognitive disorder, and 9 (3.6%) HIV-associated dementia. One-year incidence was high (37.2%, 95% CI 25.9 to 51.8), but some reversibility (17.6%, 95% CI 10.0–28.6 n = 16) was observed. Conclusions: HAND appear highly prevalent in older PLWH in this setting, where demographic profile differs markedly to high-income cohorts, and comorbidities are frequent. Incidence and reversibility also appear high. Future studies should focus on etiologies and potentially reversible factors in this setting.