Digging for Pathogens: Ancient Emerging Diseases-Their Evolutionary, Anthropological and Archaeological Context (review)

Charles L. Greenblatt, ed. Digging for Pathogens: Ancient Emerging Diseases--Their Evolutionary, Anthropological and Archaeological Context. Center for the Study of Emerging Diseases. Rehovot, Israel: Balaban, 1998. ix + 400 pp. Ill. $49.00 (paperbound).

The Western world is becoming increasingly alarmed over the threats presented by new or reemerging diseases such as drug-resistant pathogens, tuberculosis, Legionnaire's disease, HIV and Ebola viruses, prions, mad-cow disease, and new strains of the cholera bacillus. As a result, in 1996 the Center for the Study of Emerging Diseases (CSED) was established in Jerusalem; a year later, its first symposium on the Archaeology of Emerging Diseases was held, the proceedings of which make up the contents of this volume. Although each chapter includes a rich bibliography by which the uninitiated could bring themselves up-to-date in this field, the text, particularly in the third and final section of the book, is necessarily directed primarily toward experts in the field. The more general readers should, however, find something of interest in the first two sections dealing with the evolutionary, anthropological, and archaeological contexts.

Unfortunately, most authors of these papers fail to address what I regard as the fundamental issue, best expressed by a critic from the Centers for Disease Control (CDC): such studies, he has argued, represent "fun science but [are] not terribly enlightening in terms of what we ought to be doing now to protect the public health" (p. 57)--putting into question the very existence of the CSED, which was expressedly formed to develop "new concepts . . . for research, understanding and therapy for the emerging diseases" (p. 2). I would argue that the relevance of this symposium to the practical problems presented by these emerging diseases should have formed the focus of the symposium, or at least of some of the papers. Many readers outside the conference itself would need convincing that it was not simply another piece of academic self-indulgence. But the question is rarely posited--most participants, I assume, believing in the righteousness of their cause. Most are content simply to breathe motherhood statements into their papers and then get on with the business at hand. "While emergent diseases may seem novel," one author writes, "they are the result of a long evolutionary history, whose deciphering may provide part of the key to their control" (p. 15). Given that most papers deal only with this fascinating decipherment, I am left wondering about the key. Even Charles Greenblatt's overview (chap. 2), entitled "Why Knowing the Causes of Ancient Diseases May Contribute to Our Understanding of Emerging Diseases," fails to deliver, partly because the question is rarely posed by those who follow.

But there are a couple of exceptions. Paul Ewald, in an otherwise standard and well-written academic paper on the evolution of virulence, is the only one who actually quotes Dr. Fackelmann, the CDC critic. But his answer is quite shattering--a reinvention of the wheel. Having argued that high levels of virulence are the result of selective pressures that can be stable over time (contrary to earlier views, which equated virulence with a short-lived maladaptation), he then suggests that the virulence of a disease could therefore be diminished by changing selective pressures: by, for example, making houses mosquito-proof, or by eliminating the disease vectors from houses (p. 58). Neither I nor Ronald Ross can quite understand how this puts us in "a better position to meet the challenge of emerging diseases" (p. 6).

A much more novel suggestion is given by Shmuel Halevy in his paper on the algal inheritance of pathogenic protozoa. Although the paper is badly undermined by clumsy wording that implies that both algae and protozoa are natural groupings, that the phylum Apicomplexa is another name for the trypanosomes, and that by a sort of Lamarckian ascent, algae became protozoa and "fish colonized the land" (p...