THE NATIONAL ORGANIZATION for
Rare Disorders (NORD)'s website <www.rarediseases.org> includes
information about AIDS and describes the official definition of
a rare disease as any that currently affects fewer than 200,000
According to the CDC's latest available AIDS data, the HIV/AIDS
Surveillance 1998 Year-end Report (10:2, available at www.cdc.gov
or 800-458-5231), the number of "persons living with AIDS"
-- what it also calls "AIDS prevalence" (page 25) -- was
270,841 in 1997, the latest year for which it offers statistics.
Although that figure barely lies above 200,000, it includes the
many AIDS cases (including a majority of initial diagnoses) that
involve symptom-free HIV-positive people who simply have low CD4
immune cell counts. And each year through 1994 -- after ten years
of loud official hysteria about a raging epidemic -- AIDS prevalence
fell bellow 200,000. It didn't even exceed 100,000 until 1991 (1997
Mid-year Report ). Only the 1993 AIDS redefinition, expanded
to include illness-free people with low CD4 counts, nudged AIDS
prevalence over the 200,000 mark. I couldn't find any data that
estimated the fraction of current AIDS patients who lack any clinical
NORD vice-president, Maria Harden (203-746-6518 <orphan @rarediseases.org>)
said NORD doesn't keep a list of which diseases qualify as rare
because the list changes so often.
Some rare diseases eventually break the 200,000 threshold, she said,
and some non-rare diseases may get divided into sub-categories that
qualify as rare in order to qualify for the Orphan Drug Act. That
law gives drug companies 50 cents for every dollar they spend developing
drug treatments for rare diseases.
So who keeps the list of diseases regarded as rare? The National
Institutes of Health's Office of Rare Diseases, she said. Its director,
Steve Groft (301-402-4336, <email@example.com>, www.rarediseases.info.nih.
gov), confirmed NORD's definition of a rare disease. "It [AIDS]
did at one time qualify," he said. "However, once the
[low] T-cell count [was introduced as an AIDS condition] the number
of AIDS cases went over the 200,000 threshold figure. Each individual
opportunistic infection associated with HIV/AIDS, though, still
But what about the 270,084 figure minus anybody who merely has a
low CD4 count but no clinical illness? Would symptomatic AIDS today
qualify as rare? Neither he nor anybody to whom he referred me knew
how many of the 270,084 living American AIDS patients had low CD4
counts as their only AIDS condition. As far as I can tell, nobody
has compiled that statistic. All we know is that according to the
CDC HIV/AIDS Surveillance Reports , each year since
1993 most new diagnoses involved people with low CD4 counts as their
only AIDS condition. Groft agreed that if only symptomatic patients
were considered, AIDS might still qualify as a rare disease, and
that in any case, the 270,084 figure is pretty close to rare anyway.
I asked if he thought this contradicts the official message so successfully
received by Americans that "everyone is at risk" and that
AIDS is a major health threat. All he would say is that, "I
don't think we can be cautious enough over one source of HIV, that
being contaminated blood."
-- Paul Philpott