Table 1 El Niño-Associated Disease Transmission Enhancement in Human/Livestock Populations: Examples.

Cholera

Africa^52,80: Great Lakes region; Asia^{10,51,81,82,83} South Asia: Bangladesh, India (coastal), Sri Lanka;

Warmer water temperatures promote bacteria proliferation; flooding causes contamination of water sources, and may increase susceptibility to infection via stress.

Dengue/chikungunya

Asia/Pacific^{10,17,84,85,86,87}: Indonesia, Thailand, Pacific Islands, Australia (Queensland); North America^88,89,90: Mexico, United States (southern tier); Northern South America: Caribbean Islands^10,91, French Guiana, Suriname

Dry conditions: Peri-domestic water storage promotes Aedes aegypti mosquito vector breeding; elevated temperatures reduce the virus extrinsic incubation period in Ae. aegypti and Ae. albopictus vectors; warm, dry conditions may promote vegetation patterns favorable for vector development. Wet conditions: Elevated rainfall promotes Ae. aegypti and Ae. albopictus breeding.

Hantavirus infection

Asia^92,93,94,95: China (eastern; hemorrhagic fever with renal syndrome); North America²⁰: United States (southwestern; hantavirus pulmonary syndrome)

Elevated rainfall increases food availability for rodent reservoirs (vegetation), which expands rodent populations and may promote contact with humans.

Malaria

South Asia^10,96,97: India, Sri Lanka, Bangladesh; South America^10,98,99,100: Colombia, French Guiana, Guyana, Peru (coastal), Venezuela, Africa: Great Lakes Region

Elevated rainfall promotes Anopheles mosquito vector breeding and survival, and vectorial capacity.

Plague

Africa¹⁰¹: Madagascar; North America¹⁰²: United States (western)

Heavy rains increase food availability for populations of susceptible rodents; cooler temperatures may increase infectious flea abundance.

Rift Valley fever

Africa^7,13: East Africa

Flooding of dry mosquito vector habitats promotes hatching of (transovarially-) infected eggs, and vector breeding and survival.

Respiratory illness

Asia^103,104: Southeast Asia/Indonesia

Drought may contribute to forest fires, which cause air pollution that may increase risk of respiratory infection.

Ross River virus disease

Asia^10,105: Australia (Queensland/Murray-Darling River region)

Warm conditions may increase mosquito vector longevity, and thereby vectorial capacity.