The Uncertain Transition Between the Second and Third Cholera Pandemics (1830s–1840s)

The timeline between the end of the Second Cholera Pandemic (1826–1837) and the beginning of the Third Cholera Pandemic (1839–1860) is not universally agreed upon. Some sources suggest a gradual decline of the second pandemic, while others argue that a new surge from Bengal in 1839 marked the start of the third pandemic.

Competing Interpretations of the Pandemic Transition

1. The Traditional View (Second Pandemic Ends in 1837, Third Begins in 1846)

   • Many historical epidemiological studies define the Second Cholera Pandemic as ending by 1837, when cases in Europe, Africa, and the Americas subsided.
   • They identify the beginning of the Third Cholera Pandemic around 1846, when a new global outbreak spread from Bengal to Russia, Iran, and Europe.

2. The Alternative View (A Bengal Surge in 1839 Marks the Third Pandemic)

   • Some sources argue that cholera never fully disappeared after the second pandemic, and a surge from Bengal in 1839 triggered a new wave of infections, making it the start of the Third Cholera Pandemic.
   • This perspective suggests that cholera remained endemic in South Asia, with waves of outbreaks periodically spilling into other regions.

What is Agreed Upon?

• Regardless of the precise starting date, cholera remained a global threat throughout the 19th century, with recurring outbreaks in Europe, the Middle East, Asia, and the Americas.
• The 19th century’s successive cholera pandemics led to significant developments in public health, including:
  • Quarantine measures.
  • Improvements in sanitation and water supply.
  • The eventual scientific discovery of cholera’s bacterial cause by John Snow in the 1850s.

Conclusion – A Pandemic Without Clear Borders

Because cholera remained endemic in India and persisted in various regions, the transition between the Second and Third Cholera Pandemics is difficult to pinpoint with certainty. Whether 1839 or 1846 marks the start of the Third Cholera Pandemic, it is clear that cholera was an ongoing global crisis throughout the 19th century, shaping public health policies worldwide.