Risk factors for symptomatic HIV-associated neurocognitive disorder in adults aged 50 and over attending a HIV clinic in Tanzania

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.