| 167–170 | Roman Empire, Asia Minor, Greece, Gaul, Egypt, Italy | Plague – probably bubonic – is brought back from the East by Roman troops. Asia Minor, Greece, Gaul, and Egypt are affected as well as Italy. |
| 309 | Roman Empire | A plague that may be related to anthrax spreads across the Roman Empire, causing a drastic decline in the population. |
| 542 | Eastern Roman Empire, Egypt | Huge numbers of invading rats from Egypt bring bubonic plague to Constantinople. In the following years, it will spread across the whole of Europe. |
| 1333 | China | The Black Death (a combination of bubonic and pneumonic plagues) appears in China, afflicting a population weakened by starvation. It will be spread in the West by travellers and merchants returning from the Far East to Europe. |
| 1343 | Khanate of the Golden Horde, Genoa | Tatar forces of the Khanate of the ‘Golden Horde’ are struck by Black Death while besieging the Genoese trading town of Caffa in the Crimea. Escaping merchants carry the disease across Europe. |
| 1347 | Europe | The Black Death (bubonic plague) breaks out in Europe. It first appears in Constantinople (modern Istanbul, Turkey), Sicily, Naples, Genoa, and the south of France, but quickly spreads over the whole continent. The disease is borne by bacteria carried by fleas and spread by rats. |
| 1348 | Europe | The Black Death (a form of bubonic plague) spreads in Italy, and into Spain, central and northern France, and southern England, reducing populations by more than half in some parts. |
| 1349 | Europe | The Black Death (a form of bubonic plague) spreads to northern England, Ireland, and Scandinavia, and to Germany and the Swiss Confederation, where Jews are massacred for their supposed responsibility for the pestilence. |
| 1349 | England, Scotland | The Black Death lays waste to England, wiping out between a third and a half of the population. An invading Scottish army carries the disease back over the border. |
| 1350 | Scotland | The Black Death (a form of bubonic plague) spreads to Scotland, when forces invading England return with the disease. |
| 1352 | Europe | The Black Death (a form of bubonic plague) spreads eastward across Europe, reaching Moscow, Russia, and returning towards India and China. |
| 1383 | France | Ships entering Marseille, France, are required to spend 40 days in isolation, quarantina, to prevent the spread of plague. |
| 1518 | Central America | The first known smallpox epidemic in the New World breaks out in the Caribbean islands. In the next hundred years, epidemics of smallpox, measles, and influenza kill over 90% of the indigenous American population. |
| 1525–1527 | Inca Empire | An epidemic, probably smallpox or measles, decimates the Inca Empire. It is spread via Chiriguano raiders of the Chaco from the Spanish on the Rio de la Plata. Among the dead is the Inca ruler, Huayna Capac, whose failure to nominate a successor leads to civil war. |
| 1545 | Mexico, New Spain | A smallpox epidemic devastates Mexico's native people, killing 800,000. |
| 1711 | Europe | Bubonic plague kills half a million people in Europe. |
| 1832 | UK | There is a cholera epidemic in Britain in which around 20,000 people die. |
| 1840 | world | A second worldwide cholera epidemic begins. |
| 1840–1860 | world | A cholera pandemic kills millions of people worldwide. |
| 1854 | England | English physician John Snow traces a local epidemic of cholera and typhoid to a communal pump in Broad Street, London, England. He discovers that the well's water supply is being contaminated by a leakage from a neighbouring sewage tank. |
| 1889–1890 | World | A pandemic of influenza, called the Russian flu, seeps the world. Beginning in Russia, it then spreads to the rest of Europe, China, and North America by 1890. It kills nearly 250,000 people in Europe and about 500,000 people worldwide. |
| 1918–1919 | | A worldwide pandemic of Spanish influenza (so called because of its particular virulence in Spain) or Encephalitis lethargica (sleeping sickness) kills over 20 million people, more than were killed during the conflicts of World War I. The movement of the armed forces at the end of the war promotes its spread. |
| June–October 1932 | USA | Over 4,000 people die from cholera in New York City. |
| 26 October 1977 | Somalia | The last known case of smallpox is reported, in Somalia. |
| 15 May 1990 | UK | Home-produced beef is banned in UK schools and hospitals as a result of concern about bovine spongiform encephalopathy (BSE or ‘mad cow disease’). |
| March 2003 | | A killer pneumonia-like virus identified as severe acute respiratory syndrome (SARS), seemingly originating in China and south- east Asia and responsible for over 70 deaths so far, spreads more widely as cases are reported across Europe and North America. |
| May 2003 | | Concern over the international spread of the SARS virus (severe acute respiratory syndrome) continues as Taiwan reports an increase in cases and the virus unexpectedly resurfaces in Toronto, Canada, in a second outbreak. |
| 23–24 June 2003 | China Hong Kong | The spread of the deadly SARS virus (severe acute respiratory syndrome) is seemingly being brought under control as the World Health Organization (WHO) lifts warnings against travel to the two previously worst affected areas of Beijing and Hong Kong in China. |
