SILENT KILLERS; SEX, DRUGS, WAR AND TRAVEL ARE HELPING TO SPREAD DISEASES RAPIDLY WORLDWIDE; THE COMING PLAGUE: NEWLY EMERGING DISEASES IN A WORLD OUT OF BALANCE, BY LAURIE GARRETT (FARRAR, STRAUS & GIROUX: $25; 750 PP.) reviewed by Fitzhugh Mullan

As medical students in the mid-1960s, we paid little heed to public health. Our one public class was a half-credit, half-term sleeper late in the second year when all we cared about was starting the third year when we would begin "real" doctoring. Neither did we accord much respect to the monumental public health achievements of the past, cleaning up the human condition, virtually doubling the American life span in the course of the previous century, nor did we have any inkling of the vulnerability of those victories. We were focused on the curvature care of individuals -individuals with heart disease, cancer and stroke, diseased of aging in a society that, to the extent we even thought about it, believed it had conquered infectious disease.

The students of the 1960s, schooled in a culture that accorded little importance to infectious disease and population medicine, are today's leaders in a world whose biology and epidemiology are worrisomely different from what was expected. Historic killers such as TB and measles are on the rise, cholera and plague remain much with us, and new lethal pathogens are erupting regularly. These ugly realities are both symbolized and, for practical purposes, trumped by the global pandemic of AIDS that, according to some estimates, promises to infect 100 million people by the early years of the 21st Century, leaving incalculable devastation in its wake.

This microbiological resurgence in a world grown complacent is the topic of Laurie Garrett's "The Coming Plague: Newly Emerging Diseases in World Out of Balance." Her treatise is encyclopedic in detail, missionary in zeal and disturbing in its message. By the mid-20th Century, many scientists and policy makers assumed that vaccines and antibiotics would soon tame the world of infectious disease. This confidence was not limited to the West. In 1963, Chairman Mao confidently joined the struggle against "pests," declaring war on schistosomiasis in China.

But Garrett's chronicle of these pests does not play out so simply. While "Smallpox Zero" (the global eradication of small pox) was achieved in 1977, that triumph stands as mankind's only definitive victory over infectious disease. Malaria, once targeted for extinction, remains very much at bay, as are polio and measles, diseases for which excellent vaccines exist. More disturbing has been the appearance of an array of disease that are either new or newly prominent due to changing ecology. Lyme disease is identified as a tick-borne infection on the coast of Connecticut and 15 years later has been diagnosed in all 50 states. The Marburg virus is established as the cause of a deadly hemorrhagic fever killing scientists working with primates in Germany and Yugoslavia but its origin is in the jungles of East Africa. Similar viruses dubbed Ebola and Lassa cause lethal epidemics in African communities and recede again. Legionnaires' disease and Toxic Shock Syndrome are newly virulent manifestations of known bacteria, and the Hantavirus that suddenly kills people in the rural Southwest is a new genetic variation of an old virus carried by an unusually robust population of deer mice.

"The Coming Plague" details varieties of human behavior that, perhaps even more than the resilience of microorganisms, have promoted the spread of disease. Sex, drugs, war and travel have on their own and together created circumstances where venereal and blood-borne diseases have been effectively seeded and spread. Increased heterosexual and homosexual promiscuity and prostitution have brought syphilis and gonorrhea back from virtual extinction. Hepatitis and AIDS have followed the same routes, amplified by needle sharing, attacking knowing participants and unknowing spouses and offspring. War and civil strife have given us back cholera in Rwanda, created a seedbed for AIDS in Uganda and Tanzania, and launched drug-resistant gonorrhea in Vietnam. Air travel provides the means to send a microbe anywhere in the world with staggering efficiency.

Indeed it is the globalization and, most particularly, the "thirdworldization" of life on much of the planet that is the essence of Garrett's diagnosis. An outbreak on one continent is now a potential outbreak on all continents. The march of poverty, drugs, war and tribalism has vastly expanded the "petri dishes" in which old diseases thrive and new ones erupt. She estimates that 21 million people were living as refugees or in war zones at the end of 1993. The world's exploding population -1.5 billion at the end of the last century, almost 6 billion today and an estimated 12 billion by the middle of the next century -is, by itself, a driver of poverty and a spectacular amplifier of disease.

One has to read carefully and at some length to find signs of hope amid Garrett's disturbing annals of bad microbes, venal behavior and dissolute politics. Technologies are improving and genetic engineering, in particular, now provides magnificent tools to diagnose and trace the origin and spread of bacteria and viruses. The worldwide vigilance and competence of the U.S. Centers for Disease Control (CDC) get good marks and Garrett's endorsement as the lead planetary watchdog, given her definitive dismissal of the World Health Organization's capabilities in these arenas. In the end she argues for a brand of global communitarianism as the only possible counteroffensive to devastating diseases. "Rapid globalization of human niches requires that human beings everywhere on the planet go beyond viewing their neighborhoods, provinces, countries, or hemispheres as the sum total of their personal ecospheres." Population control, environmental preservation and human development are absolute requirements if we are to have a chance against the certain arrival of new plagues. Laurie Garrett's warning echoes John Donne's 400-year-old wisdom, "No man is an island, entire of itself; every man is a piece of the continent, a part of the main."

"The Coming Plague" makes fascinating if troubling reading. It is an important contribution to our awareness of human ecology and the fragility of the relative biological well-being that many of us enjoy. Garrett is a journalist, formerly a science correspondent for National Public Radio and now a science writer for New York Newsday. She has mastered an extraordinary amount of detail about the pathology, epidemiology and human events surrounding dozens of complex diseases. She writes engagingly, carrying her themes as well as the reader's interest from outbreak to outbreak. At times, though, her details get sloppy. Measles does not produce "a roseola rash"; roseola infantum is a disease of its own. Reagan's first HHS Secretary was Sen. -not Dr. -Richard Scweiker. Such small flaws raise unsettling questions in the mind of the reader about which of the thousands of other facts that punctuate her text might be inaccurate. Garrett's editors failed to reign in the length and unnecessary detail of the text and to help her maintain a consistent writing style. At times the book reads like a doctoral thesis with more than 100 pages of end notes (but no index) while at others it sounds more like a classic comic -"Don Francis was burned out before he even got to Harvard."

"The Coming Plague," though, is the kind of book that might have grabbed the attention of those drowsy, self-absorbed medical students in that public health class and taught them a thing or two about the world. It is certainly likely to capture the attention of readers today and raise their level of knowledge and concern about the condition of the human world and its microbial fellow travelers. Or do I have that backward? It will, perhaps, educate us about the world of microbes . . . and their human fellow travelers.