Top 10 HIV Clinical Developments of 2008 - CD8 T cells - The Body

34 • HIV JournalView—Top 10 HIV Clinical Developments of 2008
approximately 150 days or less from more chronic
infection.
Specifically, the test looks at anti-HIV IgG
(immunoglobulin G) levels compared to total
IgG concentrations as it has been observed that
anti-HIV antibodies increase relative to the total
immunoglobulin level soon after acquisition of the
virus. The combination of standard and BED testing
is known as the serologic testing algorithm for
recent HIV seroconversion (STARHS).
In 2006, an estimated 39,400 people were
diagnosed with HIV infection in the 22
reporting states. Of the 6,864 HIV-seropositive
specimens tested with the BED assay,
31% were classified as recent infections.
Extrapolating these data to the nation as a
whole resulted in a new annual HIV incidence
of 56,300 (95% CI, 48,200-64,500).
This is a 40% increase from the previous estimates.
Some have incorrectly misconstrued these results
to mean there has been a 40% increase in the
incidence of HIV—a misconception that should be
corrected with an explanation that the analysis used
a new method to estimate HIV incidence and found
that prior estimates had been inaccurately low. In
fact, overall HIV incidence has been relatively stable
over the past few years, according to this report.
FIGURE 18
Over half of the new infections were among MSM and 45%
were among black individuals. Using a model of extended
back-calculation, the investigators estimated the number of
new infections from 1977 to 2006. The result was a picture
of the domestic epidemic with a peak in incidence in the
mid 1980s followed by a decline and smaller rise in the late
1990s.
There were notable differences in trends of HIV incidence by
race and risk category. MSM were the predominant group
of infected persons early in the epidemic, but by 1988 to
1989 the incidence in this population dropped below that of
injection drug users (IDUs).
However, since 1990, HIV incidence among MSM has
progressively increased. A disproportionate number of new
infections have occurred among blacks; the incidence in
this group climbed during the first decade of the epidemic
and has remained fairly stable over the past several years.
Incidence trends among women have also been largely
unchanged in recent years.
The Bottom Line
The revised HIV incidence data paint a vivid and detailed
picture of the epidemic in the United States and likely
present a more accurate estimate of how many people
acquire the virus. While the adjustment in the number of
new cases upward by approximately 40% was surprising,
the finding that HIV remains concentrated among MSM and
blacks is not.
The rise, fall and resurgence
of HIV among MSM is striking.
Data from the National HIV
Behavioral Surveillance (NHBS)
System point to an alarming
increase in HIV acquisition
among MSM between 13 to 24
years of age, 41 demonstrating
that official and grassroots
prevention messages are not
adequately reaching or being
received by this group of men.
Likewise, the increased
burden of HIV among African
Americans can only invoke
sadness. The Black AIDS
Institute made the disturbing
observation that if their
numbers made up a separate
country, HIV-infected African
Americans would rank 16th in
the world in HIV prevalence. 42