Increasing life expectancies ,
Major causes of death in the U.S.
- TB, pneumonia, diarrhea 30%,
Diphtheria, bronchitis 5% Heart disease, cancer, stroke 16%, Injuries 5%.
- flu, Pneumonia 4% Diphtheria,
bronchitis n.s. Heart disease, cancer, stroke 62%, Injuries 4%. Globally, 1/3 die of infectious disease,
between infectious and non-infectious disease?
Infectious disease moves from person to person,
or animal to
animal; or plant to plant, more formally: transmitted from host to host,
Non-infectious disease does not move from
Germs are microbes, but most microbes aren’t germs, more than 99.9% of the microbes we
encounter don’t cause disease - some are even beneficial, they’re everywhere - air, water, food, in the body, on the
body, plants, animals, meteorites, most genetic material in us is microbial.
Microbes in and on US:
they can’t grow and reproduce there, a few are resident: they grow and reproduce, most resident microbes are
commensal, some mutualistic: help protect from disease-causing microbes.
Disease typhoid, caused by
bacterium (Salmonella typhi), Smeared on skin and on a glass slide, within 20 min., S. typhi was destroyed on skin,
it grew on glass.
Some resident microbes go from commensals to parasites, at puberty, hormone androgen
stimulates sebaceous glands on face and back and they get blocked, Bacteria, like Proponibacterium acnes, grow and
irritate the follicle area.
Other bacteria grow around secretions of the apocrine glands
concentrated in underarms and genital region, don’t function until puberty, apocrine secretions are odorless until
bacteria grow in them, purpose appears to be sexual attraction, Bacteria commensal or mutualistic?
Bacteria in the
“B. theta,” common inhabitant of human gut, Breaks down non-digestible plant material, Guides development
of intestines, Signals for fat production, when food is gone, bacteria eats from host cells, effects mouse intestine. M.
smithii, It scarfs up extra nutrients, Controls how much gets absorbed, May be a key to controlling weight, the gut is
a community of bacteria.
A harmful deviation from the normal structural or functional state of an
organism, Signs or symptoms, Normal vs. diseased, May be infectious - transmitted and caused by an agent that
reproduces in the host.
Surgeon General announced “time to close the books on infectious disease and shift all
national efforts to chronic diseases”.
The Columbian Exchange:
Periodontal disease – Bacteria, Form plaque, Biofilm, Bacteria produce toxins, kill soft
tissue and bone. Exploration and settlement of the Americas began with Columbus in 1492, first recorded smallpox
-Santo Domingo 1519, Spaniards arrived with smallpox, No Spaniards died, 1/3 to 1/2 of natives on Hispanola
(Haiti & Dominican Rep.) died.
Original visit to Montezuma, Cortez left, Months later returned, Aztecs
were suffering from smallpox, Attacked Mexico City in Aug. 1521, and was near defeat until death struck.