The Medical Detective By Sandra Hempel

Bird flu is poised to lay waste the nation, while officials dither. True or false? The recent media frenzy makes a dose of medical history particularly salutary, because whatever mess we've made of the world, it's possible to regard the past as even worse. The life and times of the cholera bacterium makes a fascinating story - with a happy ending, too.

This bacterium mutated into its deadly form in north-eastern India, and in 1817 made its first bid for world domination. It rapidly spread into Asia, killing hundreds of thousands. Death by cholera is agonising and sudden, occuring often a few hours after the outbreak of diarrhoea, vomiting and muscle contractions. No one knew why it appeared or how it travelled. After a few years, the disease mysteriously vanished. Then, in 1826, a second pandemic emerged, and this time Europeans did not escape.

Sandra Hempel recounts the horrific death tolls as cholera swept across the Continent. Ultimately, it landed on Britain's shores, in Sunderland. Attempts to quarantine ships and fumigate cargos all came to naught, not least because the authorities had no idea what caused the disease or how it spread. Isabella Hazard, a 12-year-old whose parents ran a pub popular with shipworkers, was the first to die. Soon thousands followed.

During this outbreak, John Snow was a Newcastle surgeon's apprentice, and he tended miners stricken with the disease. A shy, serious young man from a poor background, Snow moved to London to finish his training. He specialised in anaesthesia, experimenting with ether and then chloroform, and established a solid reputation. But when cholera returned in 1848, he set out - in his quiet, methodical way - to discover how it spread.

Meanwhile, a scientific inquiry had been launched, the first paid out of the public purse. Unfortunately, every one was convinced that cholera was triggered by nasty smells and vapours. When Snow's meticulous fieldwork showed that polluted drinking water, contaminated with infected sewage, was responsible, no one believed him. Hailed today as the father of epidemiology, Snow died of kidney failure, aged 45, before his classic detective work won the acclaim it deserved.

The history of that official myopia, combined with the greed of private water companies, has resonances for 21st-century Britain. Read this fascinating and entertaining book and - for a start - tap water will never be boring again.