Environmental Risks

Takatorige, Toshio; Hirose, Yukio; Nagamatsu, Shingo

Cholera is a disease caused by oral intake of water or food contaminated with Vibrio cholerae. Its symptoms are caused when Vibrio cholera reaches the lower part of the small intestine and produces toxin. There were seven cases of cholera pandemic in the nineteenth century. The first through the sixth pandemic originated from Bengal, India, and spread throughout the world. Economic and military activities by European countries in India and other southern Asian countries had strong influence on the spread of the disease in Europe. In the nineteenth century, the invention of steamboats gave a big boost to the capacity of transportation over the ocean. The opening of Suez Canal shortened the travel time between India and Europe, and it also contributed to more people and things traveling between the two places. At the same time, building infrastructures for health and hygiene had not caught up with the abrupt increase of population in cities like London or Paris, and the conditions were ready for the sudden spread. Cities of advanced countries like England started public control of water supply and sewage, i.e., measures for public hygiene of drinking water, food, and waste, and succeeded in terminating the spread. Other regions with insufficient hygienic environments still suffer from the spread. The 2015 WHO estimation counted 1.3 to four million cholera patients a year and 21 to 143 thousand annual deaths due to it.