Cholera typically affects the country during the rainy season, from December to March, during which time it remains contained around Lake Malawi in the south and results in about 100 deaths each year.
Flash floods spread sewage into lakes and boreholes, washed away pipelines and sanitation infrastructure, and ruined roads integral to the delivery of supplies. By one government estimate, Ana alone destroyed 54,000 latrines and about 340 wells. People displaced from their homes turned to whatever water sources were available, often ones that were highly contaminated, and transmitted the disease as they moved to new areas.
“With a severe shortage of water, the remaining sources become easily contaminated, because everyone is using them for everything,” Ramadan said. “We have seen that in the greater Horn of Africa.” “We know cholera is seasonal in much of the world, but the associations between precipitation, drought, floods, and cholera are not really clear,” Azman said. “In some places, more precipitation increases cholera risk. In some places, it’s less precipitation.”
Research suggesting that the Vibrio bacteria itself thrives and spreads more effectively in an aquatic environment under increasing temperatures has largely been discredited, said Azman.