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TIME: Almanac 1990
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1990 Time Magazine Compact Almanac, The (1991)(Time).iso
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100989
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10098900.028
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1990-09-18
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MEDICINE, Page 103A Recount of AIDS CarriersThe epidemic may not be as widespread as once assumed
One of the most maddening -- and frightening -- aspects of the
AIDS epidemic is that no one knows how many people have been
infected with the deadly virus. It can lie dormant in the body for
years before producing symptoms. U.S. health officials have
estimated that between 950,000 and 1.45 million Americans have
picked up the virus, but that is based on spotty data. Admits a
federal AIDS expert: "It's just hard to take those numbers
seriously."
But now there is a set of numbers that may deserve to be taken
seriously. Joel Hay, a health economist for the Hoover Institution
at Stanford, has used a statistical tool called "back calculation"
to analyze data on AIDS infections. His surprising conclusion:
about 640,000 Americans carry the virus. If he is right, the
epidemic, while still devastating, may be only half as widespread
as generally believed.
Hay's calculation is based on the observation that in a
specific group of people carrying the AIDS virus, a certain
percentage will develop symptoms within a given period of time. For
example, it appears that roughly 6% will come down with the disease
in the second year after infection. Since the Government has
accurate figures on how many people have developed AIDS, Hay was
able to work backward to figure out the number of those who carry
the virus.
The economist uses his techniques to predict the rate at which
new AIDS cases will be reported, and his projections seem to be on
target. Says a Government scientist: "Every month Hay's numbers
look better and better, while the official estimates look worse."
AIDS activists doubt Hay's figures and fear that they could
cause the nation to become less concerned about the disease. The
critics think that the use of anti-AIDS drugs has delayed the onset
of symptoms in many people and thus made the economist's
calculations erroneous.
The Government may settle the issue with a national AIDS
survey, which began last week in Dallas. The residents of 3,400
households were sent letters asking them to take anonymous AIDS
tests and answer questions about their sexual practices and drug
use. Some AIDS groups protested, charging that the money used for
the survey could be better spent on treatment and the search for
a cure.