Cholera, Geography of

Global History of Cholera

To date, the world has experienced seven cholera pandemics, beginning with the 1817 to 1824 pandemic in the Bay of Bengal, which diffused across the Indian subcontinent, Asia, and the Russian Empire. The second pandemic spread through Europe and the United States, and the third through sixth pandemics affected parts of Asia, Africa, Europe, and South America. All were caused by the classical biotype of cholera. A new biotype of cholera called “El Tor” caused the seventh pandemic, which began on Celebes, Indonesia, in 1961 and spread to Asia in the 1960s and to the Middle East and Africa in the 1970s. By 1991, nearly 140,000 cases of cholera were reported among 19 African nations, and the disease reappeared in Peru after 100 years of absence. A new strain, V. cholerae O139, was identified in 1992 during an outbreak on India's eastern coast. Cholera remains endemic in countries throughout the developing world but has been nearly eradicated in industrialized nations. Cholera was the most frequently mapped disease of the 19th century. Dr. John Snow was an influential figure during this period for his involvement in identifying the source of the 1854 cholera outbreak in London. His map of cholera cases around the heavily trafficked Broad Street Pump helped identify the link between cholera and water. Contrary to miasma theory, which claimed [Page 402]that cholera transmission was airborne, Snow identified the link between the Thames River water from the Broad Street pump and the cholera outbreak in London and had the pump handle removed in 1855.

Figure 1 Countries reporting cholera outbreaks and imported cases, 2006–2008

Source: World Health Organization, 2008. All rights reserved.

Cholera in the 21st Century

Cholera outbreaks continue to burden areas of the world lacking safe water and sanitation (see Figure 1). Cholera remains prevalent in South Asia and is common in other resource-poor areas. In August and September 2008, cholera cases were confirmed in Baghdad, Misan, and Babil provinces in Iraq. The reemergence of cholera followed an outbreak in September 2007, with 4,696 cases and 24 deaths. African nations continue to experience cholera outbreaks. In 2008, following floods, Namibia and Angola experienced outbreaks. The Congo, Nigeria, and Guinea Bissau also endured cholera outbreaks. These countries all share a commonality: Political unrest or outright war have disrupted water, sanitation, and health infrastructure, resulting in large cholera epidemics.

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