The following is a excerpt and summary of conditions favorable to the spread of cholera from the cholera exercise webpage. Transmission of cholera is through consumption of contaminated food or water. The coastal area of Peru has desert conditions but also rivers that flow westward down from the mountains which are used for irrigation and create oases where the combination of stagnant waters and high population densities are favorable to the spread of waterborne disease. A traditional practice in dry coastal plains is to fertilize with sewage when water is scarce. Consumption of raw fish and vegetables may help the bacteria spread.
Cholera is also an infection associated with poverty.
Officials say poor water supply and overcrowding of shanty towns that surround coastal cities helps spread the disease. Poor infrastructure results in poor water quality. Examples include chlorination not at optimal levels and low water pressure at times allows waste water to flow into pipes that are cracked. Poor health care makes people more susceptible to the bacteria. Malnourished individuals are many times more likely to develop symptoms of the disease than health individuals.