Transcript Fungus & Prions


Caused by parasite
› Transmitted by mosquito
› Once injected into the human, the parasite
grows and multiples first in the liver and then
the red blood cells.

Symptoms appear 710 days after
infection

Patient will
experience:
› Fever, chills, sweats,
headaches,
nausea, body
aches, general
malaise

About 1,500 cases reported every year in
the U.S.
› From travelers and/or immigrants
› Malaria considered eradicated from U.S. in
1950’s.

3.3 billion people diagnosed worldwide
› Thrives in tropical and subtropical areas.
Multicelled organisms
 Contain polysaccharide – chitin
 Reproductive structures – spores
 Cause disease by interfering with normal
organ structure and function or by
inflammation or allergy


Most pathogenic fungi are molds
› Mold common in soil, air, water, dust
› Aspergillus mold is most common

Recent multistate fungal meningitis
outbreak…
Picture: (CNN, 2012)

Inflammation of the protective
membranes that cover the brain and
spinal cord.

Many different types: fungal meningitis is
NOT contagious but still serious.

Symptoms include:
› Fever, headache, and stiff neck

Normally does not cause disease, but takes
advantage of a weakened immune system
› “opportunistic”
› Ex: Athlete’s foot fungal skin infection
 Infects about 10% of US population
 Topical creams prevent new growth, but don’t kill
fungi already there
 Often comes back
 Prevention

Ex: Candida yeast infection
› White or yellow curd-like patches (colonies)
› Thrives in moist & warm environments:
 Mouth/throat, Digestive tract/anus, penis,
vagina
› 75% of women will get a vaginal yeast
infection in their lifetime.

Prions (Pree – ons) = Proteinaceous
Infectious particles

Mutated prions cause:
› Mad Cow Disease in cows and
› Variant Creutzfeld-Jakob Disease (vCJD) in
people
An infectious agent composed only of
protein
 All known prion diseases affect the
structure of the brain or other neural
tissues by inducing abnormal folding of
normal cellular proteins in the brain
 Usually progresses rapidly and are
currently untreatable and fatal


Prions can jump from one species to
another, but easier among same
species.
› “Species barrier” somewhat protective
› Cow by-products fed to other cows
› In cows: Bovine Spongiform Encephalopathy

Symptoms
› Loss of coordination
› Dementia
› Brain full of holes (sponge)
› Death
Mad cow disease 1st identified in 1980s in
Britain
 217 people from 11 countries have
contracted or died from vCJD to date

(CDC)
› 170 in United Kingdom
› 25 in France
› 3 in U.S. – believed exposed in UK in 1980s
CDC: “The risk of getting mad cow
disease from eating beef from European
cattle is about 1 in 10 billion”
 CDC: “The risk to human health from BSE
in the United States is extremely low”
 While the risk is small, it takes 10-20 years
from infection to the onset of disease –
so who really knows the risk??

(10/2003)
(2007)


USDA budget for
2007: cut back on
cattle testing
Less than ½ of 1%
(0.006) tested!

Public health control measures to keep
infected meat out of the human food
chain.
› No downer cows (12/2003)
› No cows fed to cows (1997)
› Prohibition of certain cow parts in the human
food supply (2006)

Ground beef a source?