A Field Guide to Germs
A Field Guide to Germs is the kind of catchy title that brings to mind all sorts of offbeat images — a pith-helmeted scientist peering into a microscope, amateur naturalists afield looking through very large magnifying glasses, or groups of odd-looking organisms leering at an open book, making rude comments about cilia or pseudopods.
But while this book has a lighthearted title, the things it catalogues aren't funny at all. In 70 brief, alphabetically arranged entries, Wayne Biddle describes the causes of literally billions of deaths and endless human misery. Splitting headaches, diarrhea, fevers, rashes, coughing, cramps, paralysis, blindness, bleeding, ruined joints, wasted muscles appear on every page, along with bleak statistics of infections and deaths. Fortunately, Biddle manages to make mayhem so interesting that we read on, avidly.
A surprising number of the diseases Biddle describes are preventable or treatable. Malaria, a periodic fever afflicting some 400 million people, causes between one million and three million deaths per year. Although it has been almost eradicated in Europe and the United States, malaria remains common in Asia and South America, and in tropical Africa it is out of control. Measles vaccinations are cheap and effective, yet "about a million people, mostly children, die every year around the world" from this disease. Hepatitis A thrives largely "wherever sanitation and hygiene are poor"; a new vaccine is available to prevent it. Even the kinds of sexually transmitted diseases that can't yet be cured, like HIV, herpes and the papilloma viruses, can be prevented by a few changes in behavior.
Another group of illnesses, though widely feared, are extremely rare. Botulism, caused by a toxin produced by the Clostridium botulinum bacterium, never accounted for more than about 35 incidents per year in the United States. Those numbers peaked in the 1930s. Tetanus (117 cases in the United States since 1989-90) and rabies (20 confirmed American cases since 1980) have similarly inflated reputations as dangers.
It is the mysterious, however, that most people fear, and Biddle's list of strange diseases named after the places they were discovered is enough to make readers turn in their passports. The insect-borne arboviruses (the name describes arthropod-borne viruses), and rodent-borne arenaviruses and hantaviruses, sound especially frightening. Junin, Lassa and Mapucho hemorrhagic fevers are caused by arenaviruses carried by bats, rats and mice. Rocky Mountain spotted fever reaches us through ticks, and mosquitoes are the agents of yellow and dengue fevers, malaria and several kinds of encephalitis.
Every book of lists inspires readers to look for what's missing. Dental caries, gangrene, gingivitis and sleeping sickness could merit mention. Biddle might have included entries on Chaga's disease, a tropical American trypanosomal illness transmitted by a critter called an assassin bug, which may have afflicted Darwin, and kuru, a disease from New Guinea that was associated with cannibalism and is now apparently extinct. None of these omissions, however, represents a serious problem. Thousands of germs prey on human beings; any guide is allowed to select which of that army to include.
The choices covered in this guide always seem to do two things. First, each offers Biddle the chance to say something interesting or show an intriguing picture, presenting some tidbit about a symptom, statistic, scientist or victim that makes even the most obscure organism seem somehow familiar. Second, each topic lets Biddle reinforce one of the themes running through his book.
For middle-class Americans, he points out, most diseases are avoidable. Get your shots. "Drink the beer and ask for 'well done'" when traveling overseas. Wash your hands, keep the kitchen clean and practice safe sex. He stresses that mankind's less fortunate, often blamed for harboring or spreading diseases, suffer disproportionately from the miseries he catalogues. "Poverty has always put people in harm's way." Finally, he emphasizes that "medical diagnosis is not for hobbyists." Biddle offers this guide "as a bulwark against phobia." Writing with humor, good sense, wisdom and style, he has produced an excellent introduction to mankind's potentially harmful microscopic companions.
John R. Alden is an anthropologist and writer living in Ann Arbor, Michigan.