On the map
Cholera around the world since 1949: mapping the seventh pandemic
Cholera has been spreading around the world in pandemic waves since the nineteenth century. The seventh pandemic began in 1961 and has not ended. The cholera layer follows it through the reports countries sent to WHO.
See this on the map ↗A thin map in the 1950s
In the early years only a handful of countries reported cholera to WHO, mostly in South Asia. India reported 47,637 cases in 1961. Before 1970 the map rarely shows more than 12 countries. That reflects both where cholera was and who reported it.
1961: the seventh pandemic begins
The seventh pandemic, caused by the El Tor biotype of Vibrio cholerae, began in Indonesia in 1961. Genomic studies show it spread from the Bay of Bengal region in several waves. In 1970–1971 the map changes quickly: countries reporting cases jump from 12 to more than 40 as cholera reaches West Africa, the Middle East and beyond. In 1971, Nigeria, Ghana, Niger and Chad appear alongside India and Indonesia.
1991: Latin America
In January 1991 cholera appeared in Peru, the first large cholera epidemic in Latin America in about a century. That year Peru reported 322,562 cases, and Ecuador, Colombia and others followed. Reported cases worldwide jumped to 595,334 in 1991. By 1994, 90 countries reported cases, the widest spread in the series.
2010: Haiti
Cholera reached Haiti in October 2010, nine months after the earthquake, in a country with no recorded cholera for a century. Investigations traced the outbreak to a United Nations peacekeeping camp. Haiti reported 179,379 cases in 2010 and 340,311 in 2011.
2017: Yemen and the largest outbreak on record
War destroyed water and sanitation systems in Yemen. In 2017 Yemen reported 1,032,481 cases, more than any country in the series, pushing the global total to a record 1.2 million. Yemen still reported 861,096 cases in 2019.
Recent years show cholera spreading to more countries again. 27 countries reported cases in 2020, 45 in 2023 and 60 in 2024, led by Yemen, Sudan, the Democratic Republic of the Congo, Ethiopia and Nigeria.
How to read the cholera map
Cholera reporting is incomplete and sometimes avoided for fear of harming trade and tourism. Many countries report suspected cases or acute watery diarrhoea rather than laboratory-confirmed cholera. WHO estimates 1.3 to 4 million cholera cases and 21,000 to 143,000 deaths a year, far more than are reported.
Common questions
When did the seventh cholera pandemic start?
In 1961, in Indonesia. It is still ongoing.
What was the largest cholera outbreak?
Yemen’s, from 2016 onward. It reported more than one million cases in 2017 alone.
Why did cholera reach Haiti in 2010?
Investigations linked the outbreak to a UN peacekeeping camp, after the earthquake that January had damaged water and sanitation.
How many people get cholera each year?
WHO estimates 1.3 to 4 million cases a year, although far fewer are reported.