Professor Crawford presents us with a very readable introduction to infectious diseases and how they have influenced human history and development. The book begins with a brief description of bacterial evolution and how they evolved to infect animals, including humans. We learn that the beginning of agriculture enabled cross-species transfer from livestock to humans, and that many common infectious diseases share a common ancestor with animal infectious agents. This is true, for example of the SARS (Sudden Acute Respiratory Syndrome) virus, whose natural host is the Civot cat. There is a very brief but helpful introduction to epidemiological modelling. I would have liked at bit more detail on this, but it's not a major problem.
Parasites are given a good mention. The various types of Malaria species are discussed, and their interaction with humans across the generations are mentioned. I was fascinated by the section on the Schistosome fluke. The causative agent of sleeping sickness, Trypanosoma Brucei Brucei, is included.
The great plagues of history (Anthens, Antonine, Justinian, Black Death and the Renaissance plauge) are given a good mention. A discussion of whether the Black Death was caused by Yersinia Pestis was present, although I though this could have been done in greater depth.
A good thing was the inclusion of the Irish Potato Famine, and thus the point was well made that non-human infectious agents can have a devastating effect on humans. This illustrated the point that all organisms on the Earth are in a delicate balance, which is something that must be considered when planning for future societies etc.
The book ends with chapters on how infections can be treated and problems that have arisen with respect to antibiotic resistance. Possible novel solutions to this arising from genomic analysis are briefly mentioned.
This books presents a brief but valuable introduction to infectious diseases.