Plenty to worry about here
This is the revised and updated edition of 2002 of the book originally published in 1995. The book is a "field guide" only in a metaphorical sense. After all, most of the subject matter is invisible to the unaided eye.
There's an overview in the Introduction of the role germs have played in the life of humans. It's a gruesome story. There follow 161 pages focusing on the individual germs or germ genuses in alphabetic order beginning with adenoviruses and ending with Zika fever, a rarely encounter viral disease which Biddle includes, he writes, because "we need a Z." Unless I miss my count there are 74 entries.
There's more than a micron of whimsy in the text as Biddle, who is also the author of A Field Guide to the Invisible and other works, tries to lighten up the mostly depressing subject matter with witticisms, e.g., "Untreated colds last a week; medical attention can end them after seven days." (p. 129) Each entry is between half a page and a couple of pages in length except for a few of greater interest, like polio which runs to almost five pages and includes a black and white pic of a young Elvis Presley happily getting vaccinated. There are 54 illustrations accompanying the text, many of them of old time cartoons and posters calling attention to various plagues and epidemics. Especially noteworthy are some drawings warning young men about syphilis, gonorrhea and other venereal diseases, showing women as culprits, or as Biddle has it, "Always one of Shorty's girls, never Shorty."
The strength of the book is in how wide is Biddle's range of interest and in the fact that each pathogen is identified in some detail including its common and scientific names, whether it is a virus or a bacterium, a protozoan or something else (worms and prions, for example). How the disease is transmitted, its symptoms and its history are also noted. One can learn something about the nature of disease and how our immune system copes from reading the text, which is informal but not flippant.
A weakness is that he doesn't consistently explain how viruses, bacteria and other contagions actually work their horrors, although in some cases he does. Bacteria that produce deadly toxins, like anthrax are identified as causing injury "to cells and tissue." And he explains that the HIV enters and renders helpless our T-4 lymphocyte cells by getting their DNA to produce viruses. This is how viruses in general work: they enter our cells, take over the machinery, and after a bit burst out, a thousand or so strong, each virus now headed for another cell. It can be surmised how after a while a lot of our cells are out of commission and can no longer do their job. In the case of the common cold viruses, apparently they don't commandeer enough of our cells (I presume along the lining of the nose and throat) to really do us any harm. Most of the discomfort, again presumably, comes from the body's reaction to the invasion, the fever, the sneezing, the coughing, etc. But Biddle is short on this sort of explanation. But he is not the only one. I am still looking for that popular book on disease that explains in detail and specifically how each pathogen does its harm to our bodies. Are we eaten, cell by cell or are we poisoned, or are we doing okay until the pathogen reaches some vital organ where it does...what?
We are told, and Biddle in part confirms this, that recurring diseases like colds or the flu come round regularly when the weather is right to keep us indoors and sneezing on one another in closed quarters, thus effectively spreading their particles happily about. However, he only alludes to the possibility that we may be harboring many, many germs within our bodies that only become pathogenic when we are weakened or when their season, as it were, comes round. My point is that it may be the case that we can get the flu every year or so or a cold without ever coming into contact with anybody else. We may harbor the germs for life. In some cases they become subdued by our immune system, but then they may mutate so that our system doesn't immediately recognize them and they go wild.
A nice confusion that Biddle clears up is how sometimes we get a cold or the flu (viral infections) but end up with a bacterial infection to boot. Although he doesn't explain specifically how this happens, apparently the flu or cold weakens us in some way that allows bacteria a chance to do us harm, which is why some patients insist on getting an antibiotic prescription from their doctor even though they have a viral infection.
Biddle addresses the mutation issue, fueled by the overuse of antibiotics so that our bodies and those of our cattle and pigs become virtual laboratories for the development of mutant strains of microbes immune to very antibiotics we are using.
As a bonafide, card-carrying germaphobe, I can tell you that this book is definitely worthwhile, and will spur you to even greater efforts at avoidance. Beware if you tend to the obsessive, however, since after reading this you may never stop washing your hands, and may never again leave the house.
--Dennis Littrell, author of “Understanding Evolution and Ourselves”