UCSF researchers call for shift in HIV prevention priorities

By Jeff Sheehy

HIV prevention resources are not allocated in the most cost-effective fashion
say researchers at the UCSF Center for AIDS Prevention Studies (CAPS). The UCSF
researchers argue that risk reduction funding is disproportionately allocated
towards preventing heterosexual transmission of HIV even though the rates of
HIV infection among heterosexuals appear to be falling.  Conversely, the rates
of HIV infection for men who have sex with men (MSMs) have remained stable and
may even be increasing.

The researchers also call for a shift from the current focus on HIV case-based
reporting which gives “a window on the past” to an emphasis on sentinel
surveillance systems that could provide “a much needed window on the future.”

The call for the reallocation of risk reduction resources and for the United
States to finance long-term HIV surveillance systems of high-risk populations
are contained in a paper published in the October 28, 2000 issue of Science.

“If you look at AIDS cases, there is decline in cases among MSMs and an
increase in heterosexual cases.  However, if you look at the incidence of HIV,
meaning the rate of new infections, and the prevalence of HIV, meaning the
proportion of individuals in a population infected with the disease, you get a
different picture.  There seems to be a decline among heterosexuals and stable
or increasing rates among MSMs,” said Joseph A. Catania, PhD, lead author and
assistant professor of medicine with UCSF CAPS.  “Unfortunately, our focus has
been on AIDS cases which gives a picture five to ten years out of phase with
the epidemic. Frankly, we’ve lost track of the disease,” added Catania.

The paper notes that MSMs accounted for 46% of AIDS cases in 1999 and yet
received only 28% of HIV risk reduction funding.  Meanwhile, risk reduction for
heterosexuals accounted for 31% of the spending even though heterosexual
transmission accounted for just 17% of U.S. AIDS cases.  These funding
priorities make sense if the HIV epidemic is increasing among heterosexuals and
declining among MSMs.  The authors argue that this is not the case.  The paper
cites data showing that HIV prevalence and incidence among MSMs declined in the
latter part of the 1980s. However, over the last ten years, incidence among
MSMs has remained constant at one to two percent and there is strong evidence
that prevalence of HIV for MSMs has also remained stable in the 1990s.  Catania
noted, “Prevalence did decline even when incidence was stable because of high
death rates.  Now HAART (Highly active antiretroviral therapy) has brought the
death rates down.”

The authors also cite data showing that the prevalence of HIV for
heterosexuals, which has always been low (less than one percent), has decreased
over the last ten years.  This decrease along with reported behavior change,
such as increased condom use, suggest that incidence of HIV among heterosexuals
is also declining.  Also, a downward trend in incidence of HIV among
heterosexuals is consistent with observed declines in syphilis in the general
population. The researchers observe that current prevention resource
allocations are not consistent with the trends in the spread of HIV disease.

In addition, the researchers point out the difficulties faced in knowing how to
allocate prevention resources optimally in the absence of long-term
surveillance systems that incorporate the current advances in scientific
sampling.  According to Catania, at least four large surveys of MSMs and four
large surveys of high-risk heterosexual populations are needed over the next
ten years to chart accurately the direction of the epidemic.

The UCSF Center for AIDS Prevention Studies is part of the UCSF AIDS Research

Co-authors are Stephen F. Morin PhD, director of the Policy Center, UCSF AIDS
Research Institute; Jesse Canchola, MS, UCSF senior statistician, CAPS; Lance
Pollack, PhD, UCSF specialist, CAPS; Jason Chang, MS, UCSF assistant
statistician, CAPS; and Thomas J. Coates, PhD, UCSF professor of medicine and
executive director of UCSF AIDS Research Institute.