Download Asthma and allergy are just 2 of some 40 auto

4.7 Disease
Many diseases affect the human population and despite efforts to
eradicate them by vaccinations, they are still prevalent. In animal
populations, diseases help maintain sustainable population levels.
An epidemic is when a disease spreads through the human
population at a substantially faster rate than expected. When
diseases spread through the animal population, it is called an
epizootic.
While infectious diseases have always been
around, we have not been able to conquer
them because they can mutate and evolve.
In the last century, infectious diseases have accounted for more
deaths than all of the wars combined.
Many illnesses are carried by insect vectors such as mosquito,
responsible for West Nile virus, Malaria, and Eastern Equine
Encephalitis.
USGS
Lyme disease is caused by the spirochete bacteria Borellia
burgdorferi, and is transmitted by the deer tick.
Perhaps the most terrifying infection, “the Black Plague” or
Bubonic Plague was caused by a bacterium, Yersinia pestis, carried
by fleas from rodents to man.
The Black Death is estimated to have killed
nearly 2/3 of the European population in
the mid-1300s.
Center for Disease Control
Zoonotic diseases are transmissible
between animals and people.
Ex: Avian Flu, Monkey pox, and rabies
in bats.
USGS
Other potential pathogens are carried in air, dust and soils.
Recent studies show atmospheric transport of dust from northwest
Africa to the western Atlantic Ocean may be responsible for
environmental hazards, including red tides, amphibian diseases,
increased asthma in humans, and oxygen depletion in estuaries.
Africa
USGS
Water borne diseases are some of the
most important in human history.
Amoebic dysentery, typhus and cholera have often
been associated with unclean drinking water and
have killed many people.
Diarrhea kills more children in the world
today than any other disease.
Percentage of Population Without Reasonable
Access to Safe Drinking Water
Global Education Project
Reasonable access to safe drinking water is defined as the
availability of at least 20 liters per person per day from an
improved source within 1 kilometer of the user's dwelling.
The US and other countries continue to be sources of
viruses, such as measles, mumps, and influenza.
(1918 Photo From Library Of Congress)
The most deadly disease of all time was the Influenza Pandemic
of 1918-1920 that killed hundreds of thousands world-wide.
Once called the Spanish Flu, it is now thought to have arisen in
hogs in Kansas before circling the globe after WWI.
The greatest increase in diseases in the last decade has been
auto-immune disease (where the body attacks itself).
Asthma and allergy are just 2 of some
40 auto-immune diseases that tend to be
more common in women.
Organisms worldwide are affected by the spread of diseases and
by global climate change.
NOAA
Coral bleaching is an example of disease and death caused
by abnormal warming of tropical waters.
World wide economic
effects of disease are
very important due to
many bans on imported
meats due to potential
contamination.
A similar disease in humans is
CJD or Creutzfeldt-Jakob disease.
BSE or Bovine spongiform encephalothapy is a deadly disease
caused by prions (for proteinaceous infectious particle) and
transmitted by cattle through contaminated feed.
Of particular importance is highly pathogenic H5N1 strain of Avian
influenza that began in Asia in 1998 and is found in other mammals
and birds such as hogs, whales, cows, seals, tigers, ducks and
pigeons.
Kansas Dept.
of Agriculture
Plant diseases caused by bacteria, viruses and fungi result in
loss of income for farmers, reduced food supply and have
important impacts in global economies.
These diseases have killed the most
people over recorded history .
Black Death
Cholera
Diarrhea
Ebola
HIV/AIDS
Malaria
Measles
Meningitis
Polio
Smallpox
Spanish Flu
Syphilis
Tetanus
Tuberculosis
Typhus
Whooping cough