The rate of HIV-associated dementia in sub-Saharan Africa is so high that it could be among the most common forms of neurological problems in the world, researchers have argued.
According to an international study led by Johns Hopkins University, HIV-related dementia could be as common as dementia from strokes and Alzheimer's disease.
The first study of HIV dementia in Africa was based on neurological and neuropsychological tests and found that 31 per cent of HIV-positive patients had HIV dementia.
HIV dementia differs from other forms of dementia, such as Alzheimer's, because cognitive function can be restored when antiretroviral medication is used to treat the infection.
Johns Hopkins' Ned Sacktor, a neurologist and senior author of the Neurology study, said: "Clearly, large-scale testing would have to be conducted before we know the global reach of HIV dementia, but this study sends a clear message that it exists in high proportions in sub-Saharan Africa and is an under-recognised condition that needs to be studied and treated."
He added: "If the rate we saw in our study translates across sub-Saharan Africa, we're looking at more than eight million people in this region with HIV dementia."
The researchers noted there was little accurate data about HIV dementia, but cite current estimates of between nine and 54 per cent of HIV positive people suffering from dementia.