Global Warming and Public Health

Robert M. Levin, MDHealth Officer

Ventura CountyApril 7, 2008

Public Health Impacts of Global Warming

• Heat waves and deaths from hyperthermia• Fresh water shortages (due to combined effects of global

warming, overpopulation and water pollution) with wars fought over fresh water

• Air pollution related to greenhouse gases (increased disease and death due to heart attack, stroke, asthma, emphysema, lung cancer, allergy)

• Ozone depletion leading to increased cataracts, melanoma• Extreme weather events (floods and storms)• Water-borne and food-borne diseases (toxic algal blooms like red

tide, survival of viral pathogens leading to shellfish poisoning, cholera)

• Vector-borne and rodent-borne diseases (mosquitoes, ticks, rodents)

• Elevated seas levels (population exodus, aquifers threatened in San Francisco and New Orleans)

• Crop failures and famine• Economic and political stress may damage public health

infrastructure

Will global warming by itself change the boundaries of the diseases we

see?Malaria

The Little Ice Age

• Hunters in the Snow by the Flemish painter Pieter Bruegel February, 1565

Vector-borne Disease

• Disease in humans carried from another warm-blooded animal by an insect such as a mosquito, tick or sandfly.

Infectious Diseases Potentially Infectious Diseases Potentially Spread by Global WarmingSpread by Global Warming

Dengue feverDengue fever MalariaMalaria Yellow feverYellow fever Chickungunya feverChickungunya fever Epidemic polyarthritisEpidemic polyarthritis West Nile feverWest Nile fever St. Louis encephalitisSt. Louis encephalitis Lyme diseaseLyme disease EhrlichiosisEhrlichiosis PlaguePlague LoaiasisLoaiasis

LeishmaniasisLeishmaniasis Kyasanur Forest diseaseKyasanur Forest disease La Crosse encephalitisLa Crosse encephalitis Eastern equine Eastern equine

encephalitisencephalitis Japanese encephalitisJapanese encephalitis OropoucheOropouche Western equine Western equine

encephalitisencephalitis Venezuelan equine Venezuelan equine

encephalitisencephalitis OnchocerciasisOnchocerciasis

Example: The Complexity of Disease Example: The Complexity of Disease Spread - Dengue FeverSpread - Dengue Fever

Vast difference in the amount of Dengue in Vast difference in the amount of Dengue in Nuevo Laredo, Mexico and Laredo, TexasNuevo Laredo, Mexico and Laredo, Texas

Dengue Fever is called “breakbone fever”Dengue Fever is called “breakbone fever” Americans stay indoors and have air Americans stay indoors and have air

conditioningconditioning Public places in Mexico are not likely to be Public places in Mexico are not likely to be

air conditioned and are open to the air conditioned and are open to the elementselements

The Human ResponseThe Human Response

• HousingHousing

• Air conditioningAir conditioning

• Pesticides in the environmentPesticides in the environment

• Bug spray on peopleBug spray on people

• DrainageDrainage

• ImmunizationsImmunizations

• NettingNetting

• Release predator insects and sterile matesRelease predator insects and sterile mates

Leishmaniasis

• Skin lesion like bump or ulcer

• Heals spontaneously or smolders for years

• Destructive changes in nose or throat

• Disfiguring• Other form is visceral

leishmaniasis• Fever, anemia, weakness,

emaciation, enlarged liver, spleen, death

Leishmaniaisis Transmission

Leishmaniasis

Leishmaniasis in Germany

Global Warming and Public Health