A deadly dance with diseases on death row

The anthrax attack that took place almost immediately after September 11 2001 woke US society to a world we thought we had left behind. In that world, which was familiar to our ancestors, inexplicable and untraceable diseases appear, seemingly from nowhere, and attack those nearest and dearest to us. The Americans' sense that they are Masters of the Universe that was so widespread at the end of the past century is slowly slipping away.

These two books address this re-emerging world in very different ways. The first looks at smallpox. David Koplow is a professor of law at Georgetown University, and during the Clinton administration he was senior adviser to the Pentagon on biological warfare issues. He takes a careful lawyer's approach to the question of the smallpox virus. In perhaps the greatest public health triumph in history, the last reported naturally occurring case of smallpox occurred in 1977 in Somalia. Since then, the stockpiles of the virus have been reduced until there are now only two known preserved strains, one in Russia and one in the US. The question of whether these should be heated and destroyed keeps being put off. It will come up again in 2005.

The virus is thus on death row, and a simple decision should be enough to drive it to extinction. One might think that this would be a no-brainer - after all, the virus has killed perhaps 1 billion people during the lifetime of our species. But as Koplow shows, the question is anything but simple.

The first worry is whether terrorists or outlaw governments have additional stocks of the virus. This possibility has led to the beginnings of a revaccination campaign in the US and to frantic attempts to develop a safer vaccine. Unfortunately, vaccine development must rely on indirect methods, employing viruses related to but not the same as smallpox. Could a better vaccine be developed using the real virus along with appropriate safeguards? Should we therefore keep the virus rather than destroy it?

Destroying the virus may not help. It might be reconstructed in some mad scientist's laboratory, or a similar virus from the natural world might take its place. The complete DNA sequence of smallpox is known. Even if all the intact viruses were destroyed, it might be a simple task in the future to bring it back, a possibility that Koplow mentions briefly but that is worth exploring here. The genome of the virus is only 185,000 bases long, a smallish bit of DNA. In a few years, technology will have advanced to the point where it will be the work of an afternoon for a graduate student to make an exact copy of this little genome. Making an intact virus will be more difficult, and will require infection of human cells with the viral DNA and some protein molecules that will encourage the DNA to replicate and to take over the cellular machinery to make intact copies of the virus. But it will soon be possible for our hypothetical graduate student to resurrect smallpox, like a creature from a horror movie.

And what of related viruses? Monkeypox, a virus that afflicts some of our nearest relatives, has already caused some human deaths. Although monkeypox does not seem to spread readily from one human to another, it may be quite possible to tweak its genome to make it as deadly as - or deadlier than - smallpox.

So, should we get rid of the virus or not? Like any good lawyer, Koplow carefully considers the arguments for not destroying it. Is smallpox worthy of preservation, even if only on death row, under the Endangered Species Act? Will wiping it out make us less prone to agonise about wiping out other noxious, or even potentially beneficial, species in the future?

The mill of Koplow's logic grinds these arguments exceeding small and, on balance, he comes down on the side of preservation for these reasons and for the reason that smallpox may be necessary for our future defence against resurrected virus or hidden stocks of the virus. I agree with Koplow that the virus should be preserved, but wonder whether there is a better way to do it than putting it in a single freezer, no matter how heavily guarded. Can the DNA be preserved in one freezer and the protein parts of the virus be preserved in another thousands of miles away, so that reconstituted virus can be made only through a series of coordinated decisions involving many individuals?

Charles Briggs and Clara Mantini-Briggs are both involved in studying the interaction among politics, class and race warfare, and medicine and how they affect disease outbreaks in the underdeveloped world. In their book, they examine the history of part of the widespread 1991 outbreak of cholera in South America, as it affected the indigenous peoples of the Orinoco delta in Venezuela. The events that led to the outbreak, and the multitude of responses of Venezuela's socially stratified society, are examined exhaustively, though I fear that the points the authors make are sometimes hidden under layers of jargon and political correctness.

Cholera is easy to prevent - chlorination of water supplies does the Vibrio bacillus in very nicely. And it is easy to treat if caught early - drinking a dilute mix of salts and glucose will do the trick, and if the patient is unable to keep this mixture down then a sterile version of it can be given intravenously with a minimum of equipment. So what is the problem? Ignorance and superstition, class warfare that has led to dangerous neglect of elementary public-health measures and sometimes unexpected sources of damage. The authors tell the story of the 60 Minutes television documentary of 1994 that claimed that the World Health Organisation was interfering with the distribution of an oral vaccine against the disease. The political fallout for the WHO, and the resulting reinforcement of already rampant UN-o-phobia in the US, was extremely damaging. These and other threads of the authors' narrative show just how complex the question of disease prevention has become. We have not heard the last of these topics.

Christopher Wills is professor of biology, University of California, San Diego, US.