List of figures and tables -- Preface -- Acknowledgements -- Introduction -- 1. How it all began -- 2. Our microbial inheritance -- 3. Microbes jump species -- 4. Crowds, filth and poverty -- 5. Microbes go global -- 6. Famine and devastation -- 7. Deadly companions revealed -- 8. The fight back -- Conclusion : Living together -- Glossary -- Notes and references -- Further reading -- Index.