Figure 1.

Microbe hunting for cholera — then versus now, local versus global.

A) A map of the number and location of cholera cases relative to the Broad Street pump from “A report made by Dr. John Snow” accessed through Wellcome images and shared under Attribution 4.0 International (CC BY 4.0). B) A schematic of inferred global movement of the seventh pandemic cholera lineage El Tor (7PET). The 7PET lineage arose in South Asia in the 1960s and spread globally in three subtypes referred to as waves, allowing its intercontinental spread over time to be traced. Wave 1 spread from South Asia to Africa via the middle East in the 1970s and then on to South America, initiating a massive epidemic in the early 1990s. Wave 2 radiated globally to Africa and Europe as well, and was also introduced to Central America in the early 1990s. Wave 3 was introduced multiple times into Africa and infamously caused the devastating Haitian outbreak after its introduction in 2010. The arrows and timelines on this figure are indicative only, and are adapted from [18,32,33].