Gregg, the biochemist-author of Plague! (1978), is intrigued by infectious diseases--the way old ones hang on, the way new ones appear. He's also an impassioned champion of research and the public interest. So he puts more argumentation into his tales of medical detection than the master of the genre, Berton RouechÃ‰. His opening account of Hansen's disease (in preference to the pejorative ""leprosy"") cites the appalling social stigmas still attached, the limited medical interventions still available. In reviewing the 1976 swine flu scare, Gregg vents spleen at the politics involved (for a different view, see Richard Neustadt and Harvey Fineberg's The Epidemic That Never Was, p. 1282); looking at Legionnaire's disease, he celebrates the work of Center for Disease Control scientist Joseph McDade in isolating the legionelliosis bacterium. He retells the thalidomide story, excoriating the German and British firms that wittingly dispensed the drug. (Even after its withdrawal, shockingly, thalidomide continued to be sold in Japan and other countries.) He describes the plight of parents whose children have died as a result of the mysterious Reye syndrome. Among newer conditions discussed are toxic shock syndrome and genital herpes (the love virus), where more problems than solutions present themselves: Are these truly new disorders? Can effective treatments and vaccines be developed? There are also some non-infectious tales--about accidents at a Russian biological warfare plant, an outbreak of botulism in New Mexico. A wrap-up chapter examines the varied causes of birth defects, environmental and otherwise. Absorbing and sobering altogether.