Date: Thu, 2 Mar 1995 08:59:46 -0500
From: Gabo3@aol.com

New York Newsday - Thursday, March 2, 1995

On The Threshold Of An AIDS Disaster
by Gabriel Rotello

	New York - In some ways it's the most hopeful study about gay men and AIDS
prevention I've read in years. In other ways it's the most terrifying. I'm
still trying to decide which.
	The study is called "Effect of Sexual Behavior Change on Long-term HIV
Prevalence among Homosexual Men." Its authors are Martina Morris and Laura
Dean, two researchers at Columbia University's School of Public Health who
have spent years tracking the AIDS epidemic. Last year they set out to
predict its future path among local gay men. 
	Morris and Dean report that in the years before the epidemic, gay male New
Yorkers had an average of about 11 "unsafe contacts" per year, an "unsafe
contact" being a person with whom one has unprotected sex at least once. By
1991, after years of education and behavior change, gay men had reduced that
number to just one per year. Morris and Dean tried to figure out whether that
was enough to lower HIV transmission below the epidemic threshold.
	Epidemic threshold is the point at which the average infected person infects
precisely one other person. Anything above that point and an epidemic will
relentlessly grow. Anything below it, and the epidemic will shrink and
eventually die out. Using models that have proven remarkably accurate in
predicting the epidemic so far, Morris and Dean spun out the next 35 years
based on the 1991 average of one unsafe contact per year. 
	At that level, transmission among gay men lies just below the epidemic
threshold. As the years go by the percentage of gay men infected with HIV
slowly drops from around 40 percent today to a mere five percent in 2030.	To
me, this is the most important, hopeful finding in AIDS prevention in years.
It means that at 1991 levels of safer sex, gay New Yorkers had succeeded in
prevention's fundamental goal. Even without a cure or a vaccine, even if we
just continued what we were doing in 1991, future gay generations would be
spared the devastation that engulfed my generation in the 1980s and 1990s. 
	That's the good news. The bad news is that Morris and Dean created a second
model to predict what would happen if gay men slipped just a little bit in
the direction of unsafe sex. Their second model assumed that gay men had
returned to a level of two "unsafe contacts" per year instead of one, a
fairly plausible assumption considering that the original number back in 1981
was eleven.
	That small difference - between one unsafe partner and two per year -
produces disaster. Transmission rises well above the epidemic threshold in
every age category. The charts flow upward instead of down as the years roll
by, and instead of a 5% level of infection in 35 years, gay men over 40 have
a 65% level of infection. In other words, the difference between one unsafe
contact and two is the difference between an almost AIDS-free future and
absolute catastrophe.
	There are two powerful messages here. One is that it is indeed possible for
gay men to eliminate the epidemic through behavior change alone. In New York
we even know precisely what level of safer sex is necessary to get us there.
We know because we lived that level back in 1991. But the other message is
how little it would take to push us over the threshold. And how enormous the
consequences would be if that happened. "The implications of even temporary
returns to unsafe practices are not simply an increase in individual risk,"
warn Morris and Dean, "but also the persistence of HIV transmission at
epidemic levels in the [gay] population."
	Where are we today? The last time anybody checked, levels of unsafe sex were
rising among gay men in almost every study. But Morris and Dean can't really
say what the figures are. Their funding has run out.