Background: Little is known about the prevalence and burden of HIV associated neurocognitive disorder (HAND) among patients on combination antiretroviral therapy (cART) in sub-Saharan Africa. We estimated the prevalence of HAND in adult Malawians on cART and investigated the relationship between HAND and adherence to cART.
Methods: HIV positive adults in Blantyre, Malawi underwent a full medical history, neurocognitive test battery, depression score, Karnofsky Performance Score and adherence assessment. The Frascati criteria were used to diagnose HAND and the Global Deficit Score (GDS) was also assessed. Blood was drawn for CD4 count and plasma nevirapine and efavirenz concentrations. HIV negative adults were recruited from the HIV testing clinic to provide normative scores for the neurocognitive battery.
Results: One hundred and six HIV positive patients, with median (range) age 39 (18-71) years, 73% female and median (range) CD4 count 323.5 (68-1039) cells/µl were studied. Symptomatic neurocognitive impairment was present in 15% (12% mild neurocognitive disorder [MND], 3% HIV associated dementia [HAD]). A further 55% fulfilled Frascati criteria for asymptomatic neurocognitive impairment (ANI); however factors other than neurocognitive impairment could have confounded this estimate. Neither the symptomatic (MND and HAD) nor asymptomatic (ANI) forms of HAND were associated with subtherapeutic nevirapine/efavirenz concentrations, adjusted odds ratio 1.44 (CI. 0.234, 8.798; p = 0.696) and aOR 0.577 (CI. 0.09, 3.605; p = 0.556) respectively. All patients with subtherapeutic nevirapine/efavirenz levels had a GDS of less than 0.6, consistent with normal neurocognition.
Discussion/conclusion: Fifteen percent of adult Malawians on cART had a diagnosis of MND or HAD. Subtherapeutic drug concentrations were found exclusively in patients with normal neurocognitive function suggesting HAND did not affect cART adherence. Further study of HAND requires more robust locally derived normative neurocognitive values and determination of the clinical relevance of ANI.