The Go-Betweens : A Human History of Vector-Borne Disease
Andy Dobson

arthropod, n. /ˈɑː.θrə.pɒd/

A type of animal with no spine, a hard outer skin, jointed legs, and a body divided into different parts, for example a spider, crab, or ant.

Ours is a planet of arthropods. Pile them all up – the insects, the crustaceans, the arachnids, the centipedes and millipedes – and they will outweigh us humans by a factor of three.

Unsurprisingly, perhaps, we have no idea how many species of arthropod there are. The best guess is 7 million, but fewer than 1.5 million have been identified and named. Most go unnoticed; we tend to notice only the most abundant, along with those that help or hinder. A few – such as locusts, aphids, and the odd spider mite – are important crop pests; others provide products and services, such as food (lobsters and crabs, bees), pollination (bees, wasps, flies, beetles), and pest control (spiders, parasitic wasps).

                None, however, have attracted quite such urgent attention as those that act as vehicles for infectious bacteria, viruses, and other pathogens that lack alternative means of transmission. Consider malaria: If I have it, I cannot give it to you; the pathogenic microorganism Plasmodium must be pulled from my blood, flown through the air, and injected into your arm via a mobile hypodermic needle known as a mosquito.

                In this arrangement the mosquitoes are unwitting accomplices, their bodies and behaviours hijacked and manipulated to achieve the ends of an unseen master. They are not alone; pathogens also variously employ lice, mites, flies, fleas, and ticks, and when such arthropods perform the role of go-between, they are called vectors. This is their story.

                But it is also ours, because the unholy trinity of human, vector, and pathogen has been every bit as pervasive and influential in our history as its more familiar Christian counterpart. Through the habits of their reluctant go-betweens, vector-borne diseases have drawn lines on maps, raised and ruined empires, wreaked social revolutions, and decided the fortunes of princes and paupers. Napoléon was beaten by yellow fever and typhus, not by Wellington and Blücher; the economic structures of Africa were shaped as much by sleeping sickness as by colonial desires; feudalism in Europe was broken by plague.

                This book is about these stories and more, describing the ways that vectors have moulded, disrupted, and catalysed human affairs. Blending historical narrative with popular science, The Go-Betweens takes a biologist’s-eye view of history, explaining how and why these forms of disease have insinuated themselves into the past and present of human societies.