Airborne Ebola?, A theory that won't fly
Ebola and other deadly viruses have been much in the news lately, and much in people's
minds. Not just for what they are deadly at close range but for what, with sinful human
intervention, they might be: rampant, random, long-distance killers, borne on the winds.
Popular culture has a recurrent fascination with doomsday pathogens. Michael Crichton's
The Andromeda Strain
was a classic incarnation of this scary scenario. The recent sci-fi film "Species" is its
latest iteration, although this time the evil incarnate has shed its viral coating: It is
naked DNA sent from outer space and embodied in an alien-supermodel hybrid. In Richard
Preston's book
The Hot Zone: A Terrifying True Story
and the film
"
Outbreak
,"
we're frightened by real viruses, specifically Ebola. In the film,
a new mutant strain, carried by a monkey, will depopulate California unless Dustin Hoffman
can save the day, and he has only an hour or so to do it.
The ostensibly responsible media are not immune to the temptation to stir these fears.
In a May 12 editorial, the New York Times declared: "A modest genetic change might
enable Ebola to spread rapidly through the air..."
That very same day, in the news section, Times reporter Lawrence K. Altman, M.D.,
handled the matter more soberly. Reporting from the Centers for Disease Control and Prevention
in Atlanta, he wrote, "The deadly Ebola virus continues to spread in Zaire, chiefly affecting
health care workers... [It] apparently spread initially among [doctors] and nurses who operated
on a patient in Kikwit." Dr. Altman, an infectious-disease specialist who once worked at the CDC,
added, "Transmission presumably was through contaminated blood..."
Can a bloodborne or body fluid-borne virus be transformed by a single mutation into an
airborne agent (a "flyer"), as the scare scenarios imply? It's conceivable. But it's "probably
unlikely," according to virologist Beth Levine, M.D., director of virology
research in the infectious diseases division at Columbia University's College of Physicians
and Surgeons. "Single amino acid mutations can change the tropism [the residential preference]
of a virus" in some experimental situations, Dr. Levine says, "but there haven't been any
examples of such mutations actually occurring in nature, changing a virus from a bloodborne
or bodily fluid route of transmission to a respiratory route."
So, says Dr. Levine, "The media's claim is not totally without scientific basis. But there
are no precedents for it, and it's unlikely.
"I think it's irresponsible to raise that concern," she added, "because in general viruses
are very well-adapted to their milieu and they don't just suddenly change their environment."
Will this kind of level-headed assessment quell media hysteria? Stay tuned.
David R. Zimmerman
DAVID R. ZIMMERMAN, adjunct professor at the Columbia Graduate School of Journalism,
is the editor of Probe, a newsletter of science and media criticism. He has taught
at the New School for Social Research.