Preface

since the dawn of civilization and probably before. Zinsser in his classic book Rats, Lice, and HistoryU contends that soldiers have rarely won wars. Typhus and other infectious diseases have decided the outcome of more military campaigns than Caesar, Hannibal, Napoleon, and all the generals of history. Depending on the outcome for each warring faction, either the epidemics were blamed for defeat or the generals were credited with victory. Closer to our era, in the pre-antibiotic period of the twentieth century (during and after World War I), it is estimated that 25 million Russians contracted louseborne epidemic typhus, causing 3 million deaths. Lenin was supposed to have remarked that “either socialism will defeat the louse or the louse will defeat socialism.” During World War 11, two Polish physicians waged what they called a “private immunological war” against the Germans, who dreaded typhus above all. In an area covering 12 villages, the two physicians administered Proteus OX19 antigen to persons with any symptoms of epidemic typhus. German health authorities who examined the sera falsely interpreted the high positive Weil-Felix reaction as evidence of active infection, and the area was declared off-limits to the Germans. Interest in research in rickettsiology and rickettsial diseases slowly diminished as effective antibiotic therapy became available. However, on closer examination, it is apparent that rickettsioses such as the spotted fevers, murine typhus, scrub typhus, Q fever, and ehrlichioses are still global problems which pose a threat to public health. The last three decades have witnessed increasing emphasis on basic research on the rickettsiae. The Eighth Meeting of the American Society for Rickettsiology and Rickettsial Diseases, held in Diamond Point, New York, September 22-26, 1989, marks a decade since the American Society for Rickettsiology and Rickettsial Diseases was organized for regular exchange of information on scientific advances in rickettsiology. The program of this meeting, as can be seen in this volume, reflects the breadth of current research on rickettsiae and rickettsioses nationally and internationally. The topics covered at the sessions ranged from symposia addressing provocative topics such as the roles of host and rickettsial factors in severity of disease, to clinical reports of rickettsial infections in humans, the isolation and characterization of specific genes from a variety of rickettsial agents, and applications of the polymerase chain reaction. It is enheartening to note that a balanced representation of subjects emerged, with presentations by physicians, biologists, and epidemiologists on new information about chronic Q fever, particularly Coxiella endocarditis, Mediterranean spotted fever, Rocky Mountain spotted fever, human ehrlichiosis, and vector biology of murine typhus and spotted fever group rickettsiae. Impressive progress in molecular rickettsiology has pushed the field into the mainstream of contemporary molecular microbiology. Genes coding for surface proteins of a number of different rickettsiae have been cloned and sequenced. These include a variety of chromosomal genes encoding enzymes, encoding surface antigens that can be used in identificationlclassification and have potential usefulness as immunogens, or encoding heat-shock proteins. In addition, plasrnid genes encoding surface proteins of Coxiella burnetii have been described. Pro-