This was seen in the disastrous floods that occurred in the aftermath of the powerful cyclones that struck Madagascar and Mozambique in February 2000. Many people died, hundreds of thousands of people were made homeless, epidemics of malaria and cholera broke out, rich farmland was rendered useless and economic development received a severe setback. The after-effects of a major flood usually linger on for many years. The breakdown of water and sanitation services increases vulnerability to waterborne diseases. Flood damage sustained by water supply, irrigation and other water infrastructure is a major setback to health and economic development.
Environmental pollution leads to more ill-health.
For instance, leptospirosis, a bacterial disease which affects both humans and animals, can reach epidemic proportions during severe flooding because of the widespread contamination of surface water, soil and plants. Contaminated water causes 54 deaths in Milwaukee Cryptosporidium parvum was not recognized as a human pathogen until late in the 1970s. The infection, which causes abdominal cramping, nausea, vomiting and fever was transmitted through the public water-supply system. Milwaukee gets its water from Lake Michigan. Apparently, one of the city's water treatment plants failed to filter out the dangerous parasite in the untreated water.