Download Infectious diseases

Pathogens! Viruses

Core genetic material (DNA or RNA) enclosed in a
capsid

What disease killed 300-500 million people worldwide
but has since been eradicated from the human
population?
Smallpox
Progression:
 Rash
 Pus-filled
blisters
 Disfiguration and/or
blindness
 Death rate = 30%
Man with smallpox; Public Health Images
Library. Source: CDC
Who invented smallpox variolation?

The first vaccine
Edward Jenner
1749 - 1823
The World Takes Action

1967: WHO announces global smallpox
eradication program.
 Still

15 million new cases a year then
1977: Last reported naturally occurring case in
Somalia.
 Smallpox
in humans
is the only disease totally eradicated
Polio
Poliomyelitis (Polio)


Polio = gray; Myelon = marrow of spinal cord; itis
= inflammation
Highly contagious
 May
result in paralysis
 Vaccine
preventable
Polio Eradication



Is it possible??
“Hopefully by 2015 no child in the world will be
paralyzed by the disease and by 2018 Polio will
be wiped out.” – Bill Gates, 09/28/2012
The current eradication program…
Cold Versus Flu
Influenza Impact

Flu seasons vary from year to year

About 20% of US population infected every year
 Higher

among susceptible populations
Three main types of flu virus: Types A, B & C
 Type

A causes the greatest morbidity and mortality
Example: H1N1 (2009 Epidemic)
Influenza Pandemics

Since the late 19th century, four occurrences of
pandemics
 1889-1891;

1918-1920; 1957-1958; 1968-1969
2009; H1N1
 Was that the pandemic for our time??

Type A cycles every 50-100 years

What’s different about Type A influenza?
Norovirus
Measles / Rubella
Chicken Pox / Shingles
Hepatitis (virus)
HAV
U.S. Stats
HBV
HCV
25,000 new
infections/yr
43,000 new
infections/yr
17,000 new
infections/yr
Transmission
Ingestion of fecal
matter
Contact w/
infectious body
fluids
Contact w/
infected blood
Severity
Usually no lasting
damage, rarely
fatal
Most fully
recover;
Some develop
liver disease;
~3,000 die / yr
60-70% develop
chronic liver
disease; 1-5% will
die from liver
cancer
Vaccine?
Vaccine available
Vaccine available
No vaccine
Symptoms
CDC, 2012
Fever, fatigue, loss of appetite, nausea, vomiting,
abdominal pain, joint pain, jaundice
Others in the news…

Ebola (virus)

Mad cow (prion)

Zika (virus)
Pathogens! Fungus
Athlete’s Foot