Timelines

A global history of epidemics, pandemics and severe outbreaks, from the epidemic at Athens in 430 BCE to the documented end of a renewed mpox international emergency in September 2025. The survey brings together 58 outbreak and continuing-disease groups, with dated recognition, investigations, prevention milestones, accountability and evidence updates. It is a substantial selection rather than every outbreak ever recorded.

Human harm, immediate and lasting

Mass mortality is central, but deaths alone do not capture polio paralysis, congenital rubella and Zika injury, post-encephalitic disability, chronic chikungunya pain, prion disease or post-COVID impairment. Some smaller high-consequence outbreaks are included because they reveal a new agent, expose a dangerous transmission setting or cause profound harm among those affected. The timeline does not imply that every selected outbreak has the same casualty scale.

Ancient Mediterranean epidemics, Japanese smallpox, plague pandemics, colonial American catastrophes, cholera, influenza, African trypanosomiasis and leishmaniasis, HIV, meningitis, SARS, MERS, Ebola, measles, dengue and other infections are compared with their distinct geography and evidence. Tuberculosis and malaria appear through explicitly dated response milestones: 1993 and 1998 are not claims about their origins.

How a hazard becomes a disaster

Entries ask what the agent or hazard was, how exposure occurred, which people were harmed, what amplified transmission, how institutions responded and what persisted afterward. Safe water, vaccination, infection prevention, reliable medical production, food tracing, care and social support address different parts of that chain. War, colonial rule, displacement, poverty and unequal access can worsen harm without replacing microbiological explanation.

Poisoning outbreaks such as Minamata and Spain’s toxic oil syndrome have their own category. Irish potato blight and African rinderpest are included as indirect crop- and livestock-disease catastrophes: people did not acquire those plant or animal diseases as contagious human infections. Their human effects arise through food, livelihoods and associated illness.

What the evidence supports

Sources emphasize WHO, CDC, national public-health agencies, original outbreak investigations, historical testimony and pathogen-genome studies, with scholarly interpretation where needed. Ancient disease names are not automatic modern diagnoses. Athens and Cyprian remain unidentified; smallpox attribution in the Antonine epidemic is qualified. Salmonella in sampled cocoliztli victims is not proof of one cause for every death across Mexico. The cause of encephalitis lethargica remains unresolved.

Numbers preserve their scope. Reported cases, estimated infections, confirmed deaths, survey estimates, modeled deaths and excess mortality are different measures. The DRC Ebola account identifies the later WHO data update used; West African Ebola figures retain their stated surveillance source and period. Historical global death totals are not presented as complete modern censuses.

Navigation, dates and relationships

Use outbreak, region, type and role tags to separate cases and compare responses. Explanatory cards address uncertainty, causal mechanisms, measurement and disability. Relationship notes state whether a connection means a response, a later discovery or an analytical comparison. A line between two outbreaks is not automatically a transmission chain or proof that one caused the other.

All coordinates display in Gregorian CE/BCE. Coarse dates use representative year or month anchors; the first day is for positioning only. Later publication dates are distinguished from the historical events they reinterpret. Approximate date anchors can have dashed outlines; this does not label the documented epidemic itself imaginary or doubtful.

There are six definite duration bands, all for WHO international emergency designations: H1N1, West African Ebola, Zika, COVID-19 and the two separate mpox emergencies. Ending a designation does not mean transmission has ended. Continuing epidemics have moments, with no duration artificially ending on the day this timeline was created. Smallpox and rinderpest eradication are identified separately as stronger endpoints.

Illustrations

The cover is a contemporary photograph of the emergency influenza hospital at Camp Funston, Kansas, in 1918. Twelve freely licensed Commons illustrations include an original cholera map, microscopy, respiratory equipment, vector photography, a treatment unit and later memorials. Each illustrated entry explains what the image shows, gives attribution and identifies its public-domain or Creative Commons status. Microscopy and later memorials are not passed off as photographs of ancient outbreaks.

Otis Historical Archives, National Museum of Health and Medicine · Emergency hospital during Influenza epidemic, Camp Funston, Kansas - NCP 1603.jpg · Public domain. File and attribution. No changes beyond thumbnail rendering/scaling.

Selected source records

• Thucydides, History of the Peloponnesian War, Book II: eyewitness account
• Fenner et al., Smallpox and its Eradication: smallpox in the ancient world (WHO monograph)
• Spyrou et al. (2022), The source of the Black Death in fourteenth-century central Eurasia
• Vågene et al. (2018), Salmonella enterica genomes from victims of a major sixteenth-century epidemic in Mexico
• Institut Pasteur, Cholera: pandemics and transmission
• CDC, 1918 pandemic: historical account
• Donald et al. (2022), Pathogenesis of tuberculosis: the 1930 Lübeck disaster revisited
• Seaman et al. (1996), The epidemic of visceral leishmaniasis in Western Upper Nile, 1984–1994
• CDC, Multistate outbreak of fungal meningitis and other infections: final counts
• WHO, Global excess deaths associated with COVID-19, January 2020–December 2021
• WHO, Fifth meeting regarding the upsurge of mpox 2024 (published October 2025)