An international study led by Johns Hopkins suggests
that the rate of HIV-associated dementia is so high in
sub-Saharan Africa that HIV dementia may be among the most
common forms of dementia in the world, along with
Alzheimer's disease and dementia from strokes.
In the first study of HIV dementia on the African
continent using rigorous neurological and
neuropsychological tests, 31 percent of a small but
presumably representative group of HIV-positive patients in
Uganda were found to have HIV dementia, according to Ned
Sacktor, a Johns Hopkins neurologist and
senior author of a multi-institutional study published Jan.
29 in Neurology.
HIV dementia is defined as a condition in which
memory, learning, behavioral and motor disabilities
interfere with normal daily life and in extreme cases lead
to total disability and a bedridden state. Unlike
Alzheimer's- and stroke-induced dementia, HIV dementia is
treatable and potentially reversible with the same
antiretroviral medication that is used to treat the
infection. Treatment can even restore completely normal
cognitive function to some of those affected.
The study looked at 178 subjects in Kampala, Uganda,
from September 2003 to January 2004. Seventy-eight were
HIV-positive patients recruited from the Infectious Disease
Clinic in Mulago Hospital, Makerere University, and 100
were HIV-negative individuals recruited from the AIDS
Information Center to obtain normative data for the
cognitive tests.
In diagnosing HIV dementia, researchers looked at
medical history and the results of a series of
comprehensive neurological and neuropsychological tests and
functional assessments.
"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 underrecognized
condition that needs to be studied and treated," Sacktor
said.
Of the estimated 40 million adults and children
worldwide who are living with HIV infection, an estimated
27 million live in sub-Saharan Africa, according to
Sacktor.
"If the rate we saw in our study translates across
sub-Saharan Africa, we're looking at more than 8 million
people in this region with HIV dementia," Sacktor said.
Sacktor said that an extremely high rate of HIV
dementia in Africa and other poor regions of the world adds
enormously to the social and economic burden of those
regions' populations and governments. Dementia not only
disrupts jobs and adds to the cost of care but also
interferes with a patient's ability to adhere to a regular
course of antiretroviral medication, thus increasing the
risk of drug resistance. People with dementia also are less
likely to practice safe sex.
Before antiretroviral medications were available in
the United States, the rate of HIV dementia in this country
was similar to what was discovered in this study in Uganda,
Sacktor said. Unfortunately, he said, only 20 percent of
people infected with HIV in the world are getting
treatment. "We hope studies like these will shed additional
light on the devastating problem of HIV in resource-limited
countries like Uganda and encourage more programs that
bring much-needed medication to these poor regions of the
world," he said.
Sacktor said there's little accurate data about HIV
dementia patients in other parts of the world; current
estimates of the number of HIV-positive patients who have
dementia range from 9 percent to 54 percent.