Deadly Companions: How Microbes Shaped Our History

Plagues and pestilence fascinate. That is why many books for the general reader have been written about them.

Some works use disease metaphorically, such as The Plague by Albert Camus and Thomas Mann's Death in Venice. Some are fiction masquerading as fact, such as Daniel Defoe's Journal of the Plague Year. But many try to keep to the science. Their authors believe that the unembellished recital of evidence will horrify and entertain readers enough to convince them of the message they wish to convey.

Dorothy Crawford's book is of the latter kind. She gives us historical biographies of microbes that have caused human disease on a grand scale: bubonic plague and the Black Death, cholera, HIV, malaria, severe acute respiratory syndrome, smallpox, syphilis, tuberculosis, typhus and yellow fever are her major villains.

Her accounts of most of them are informative. They are up to date - which is just as well, because some of them are still with us. So in the plague canon, her book joins works such as Hans Zinsser's Rats, Lice and History.

Zinsser's book was written in 1935, and its focus on one microbe, typhus fever, means that its coverage is less comprehensive than Crawford's. But for one reason - its iconoclasm - I still prefer it. Crawford is very serious about a serious subject.

So is Zinsser, but he also says: "When a bacteriologist dies - as other people do - of incidental dissipation, accident or old age, devotion and self-sacrifice are the themes of the eulogy. Let him succumb in the course of his work - as an engineer falls down a hole, or a lawyer gets shot by a client - he is consecrated as a martyr ... As a matter of fact, men go into this branch of work from a number of motives, the last of which is a self-conscious desire to do good. The point is that it remains one of the few sporting propositions left for individuals who feel the need of a certain amount of excitement."

Crawford avoids the hero worship that Zinsser hated so much, and one that is still a feature of many popular accounts of infection. Nevertheless, she has fallen for some of the myths that continue to infect the subject.

She is right to praise the pioneering epidemiological work of John Snow on cholera in London in the mid-19th century, but she is wrong to repeat his eulogisers' claim that when he caused the handle of the Broad Street pump to be removed, "sure enough the number of cholera cases in the area served by the pump dropped dramatically".

It didn't because, as Snow's own account clearly shows, it already had. The origin of this story is clear. But nobody knows the origin of another one that appears in the book, the alleged statement in the 1960s by the US Public Health Service Surgeon General, William H. Stewart, that "we can now close the book on infectious diseases". Only secondary sources quote it. None refers to sources other than another secondary one. And the Surgeon General himself cannot remember saying it.

Crawford does a fair job of describing pandemics and their effect on humanity, but some sloppy fact-checking has let through some basic errors (such as "Amory" for "Amoy" throughout).

But my main criticism of Deadly Companions is that, cholera and typhoid apart, there is very little on microbes and the bowels. Dysentery was a major scourge of armies up to, and including, the First World War. And for most of history, diarrhoea has been one of the biggest killers of babies. It still is, in fact, where sanitation is poor. But it doesn't even appear in the index. And it is inexcusable for an account written in Scotland to ignore E. coli O157.