List of epidemics and pandemics
This is a list of the largest known epidemics and pandemics caused by an infectious disease in humans. Widespread non-communicable diseases such as cardiovascular disease and cancer are not included. An epidemic is the rapid spread of disease to a large number of people in a given population within a short period of time; in meningococcal infections, an attack rate in excess of 15 cases per 100,000 people for two consecutive weeks is considered an epidemic. Due to the long time spans, the first plague pandemic and the second plague pandemic are shown by individual outbreaks, such as the Plague of Justinian and the Black Death.
Infectious diseases with high prevalence are listed separately, such as malaria, which may have killed 50–60 million people.
Major epidemics and pandemics
By death toll
Ongoing epidemics and pandemics are in bold face. For a given epidemic or pandemic, the average of its estimated death toll range is used for ranking. If the death toll averages of two or more epidemics or pandemics are equal, then the smaller the range, the higher the rank. For the historical records of major changes in the world population, see world population.| Rank | Epidemics/pandemics | Disease | Death toll | Percentage of population lost | Years | Location |
| 1 | Plague of Justinian | Bubonic plague | 15–100 million | 25–60% of European population | 541–549 | North Africa, Europe, and Western Asia |
| 2 | HIV/AIDS pandemic | HIV/AIDS | 45 million | – | 1981–present | Worldwide |
| 3 | Black Death | Bubonic plague | 25–50 million | 30–60% of European population | 1346–1353 | Europe, Asia, and North Africa |
| 4 | 1918 "Spanish" influenza pandemic | Influenza A/H1N1 | 25–50 million | 1–5.4% of global population | 1918–1920 | Worldwide |
| 5 | COVID-19 pandemic | COVID-19 | 7.13–38 million | – | 2019–present | Worldwide |
| 6 | Third plague pandemic | Bubonic plague | 12–15 million | – | 1855–1960 | Worldwide |
| 7 | Cocoliztli epidemic of 1545–1548 | Cocoliztli, caused by an unidentified pathogen | 5–15 million | 27–80% of Mexican population | 1545–1548 | Mexico |
| 8 | Antonine Plague | Smallpox or measles | 5–10 million | 25–33% of Roman population | 165–180 | Roman Empire |
| 9 | 1520 Mexico smallpox epidemic | Smallpox | 5–8 million | 23–37% of Mexican population | 1519–1520 | Mexico |
| 10 | 1957–1958 influenza pandemic | Influenza A/H2N2 | 1–4 million | – | 1957–1958 | Worldwide |
| 11 | Hong Kong flu | Influenza A/H3N2 | 1–4 million | – | 1968–1969 | Worldwide |
| 12 | 1918–1922 Russia typhus epidemic | Typhus | 2–3 million | 1–1.6% of Russian population | 1918–1922 | Russia |
| 13 | Cocoliztli epidemic of 1576 | Cocoliztli | 2–2.5 million | 50% of Mexican population | 1576–1580 | Mexico |
| 14 | 1772–1773 Persian Plague | Bubonic plague | 2 million | – | 1772–1773 | Persia |
| 15 | 735–737 Japanese smallpox epidemic | Smallpox | 2 million | 33% of Japanese population | 735–737 | Japan |
| 16 | Naples Plague | Bubonic plague | 1.25 million | – | 1656–1658 | Southern Italy |
| 17 | 1889–1890 pandemic | Influenza or human coronavirus OC43 | 1 million | – | 1889–1890 | Worldwide |
| 18 | 1629–1631 Italian plague | Bubonic plague | 1 million | – | 1629–1631 | Italy |
| 19 | 1846–1860 cholera pandemic | Cholera | 1 million | – | 1846–1860 | Worldwide |
Infectious diseases with high prevalence
There have been various major infectious diseases with high prevalence worldwide, but they are currently not listed in the above table as epidemics/pandemics due to the lack of definite data, such as time span and death toll.- Malaria has had multiple documented temporary epidemics in otherwise non-affected or low-prevalence areas. Malaria is commonly spread by mosquitoes. The vast majority of its deaths are due to its constant prevalence in affected areas.
- Tuberculosis became epidemic in Europe in the 18th and 19th century, showing a seasonal pattern, and is still taking place globally. Its symptoms include coughing up blood. It can generally be treated with strong antibiotics; untreated TB can be fatal. An opportunistic infection, TB is the leading cause of death of those with HIV/AIDS, and is considered an AIDS-defining clinical condition. The association between HIV/AIDS and TB has been described as the "TB/HIV syndemic". According to the World Health Organization, approximately 10 million new TB infections occur every year, and 1.5 million people die from it each year – making it the world's top infectious killer. However, there is a lack of sources which describe major TB epidemics with definite time spans and death tolls.
- Hepatitis B: According to the World Health Organization, as of 2019 there are about 296 million people living with chronic hepatitis B, with 1.5 million new infections each year. In 2019, hepatitis B caused about 820,000 deaths, mostly from cirrhosis and hepatocellular carcinoma. In many places of Asia and Africa, hepatitis B has become endemic. In addition, a person is sometimes infected with both hepatitis B virus and HIV, and this population accounts for about 1% of the total HBV infections.
- Hepatitis C: According to the World Health Organization, there are approximately 58 million people with chronic hepatitis C, with about 1.5 million new infections occurring per year. In 2019, approximately 290,000 people died from the disease, mostly from cirrhosis and hepatocellular carcinoma. There have been many hepatitis C virus epidemics in history.
Chronology