Ironically, people in the organized and informed AIDS community probably are better protected against crypto, generally, than the general population, simply because they know it's out there. A large population of poor and uninformed AIDS victims will continue to drink and shower in tap water, but the people with AIDS who know what they're doing will not.
As soon as Don Maison learned John Thomas had crypto--and then realized he knew of three other recent cases--Maison rushed to install thousands of dollars' worth of membrane filters on the apartment buildings owned and managed by Aids Services of Dallas.
"It doesn't do any good to filter the drinking water," he says, "if you don't also do the ice-makers and the showers, so we had to go ahead and do it all."
But if cryptosporidium is in Dallas drinking water, even in trace amounts, what does that mean for people who do not have AIDS or any other conditions that compromise their immune systems?
Lisa Ragain, the expert who worked on the study that called Dallas an "extreme risk city," says it is possible that many otherwise healthy people may be suffering the rigors of disabling diarrhea, lasting for days and even weeks and resulting in extreme weight loss, without even knowing that the culprit is crypto.
"Crypto tends to be reported only in people with compromised immune systems," she says. "It's generally not diagnosed in the general population. It's too hard to diagnose, too hard to find in the human body."
As Laurie Garrett illustrates in example after example in The Coming Plague, science is discovering that it's not a good idea to subject anybody to repeated doses of a pathogen like crypto, because the germ may be learning: The more it sees of our defenses, the better able it may be to reconfigure itself to kill us.
In the basement of the Convention Center last week, some of the scientists and experts quietly--almost shyly at times--broached another issue with their audiences of water engineers. They talked about the moral question.
What can a society expect for itself and what may it even deserve if its approach to plague is to banish the victims from inside the fortress of community?
Jeffrey Griffiths of Tufts approached it with a complex view of self-interest: "There is some merit in thinking of sensitive populations not just as people with AIDS but also other populations [such as pregnant women and infants]," he said. "It may be unfair to fragment us.
"Perhaps we need to think of everyone in the society as being, at one time or another, immune-compromised."
Erik D. Olson of the Natural Resources Defense Council went at the moral question a little more head-on. "After all," he reminded his stony-faced audience, "the best measure of a society is how we protect our most vulnerable people.
