Food and Waterborne Diseases Flashcards
feve
Foodborne and Waterborne diseases involves the…
fecal-oral route
Compare a Bacterial Infection from Bacterial Intoxication
(whats consumed, why is it dangerous, incubation period, s/sx)
Bacterial Infection:
- pathogen consumed in food/water
- pathogens invade and multiply in intestinal lining
- Incubation period: LONG (hours to days)
- S/SX: occur slowly
-> nausea, vomitting, diarrhea, fever
Bacterial Intoxication:
- toxin is consumed in food
- toxins made by pathogen -> toxemia
- Incubation period: SHORT (minutes to hours)
- S/SX: occur quickly
-> nausea, vomitting, diarrhea, usually NO fever
Describe: Staphylococcal Food Intoxication
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Treatment, Preventative Measures)
AKA/Causasive Agent/Characteristc
- AKA: Food poisioning
- CA: Staphylococcus aureus
- Characteristic: Gram POSITIVE bacteria, cocci, clusters, present skin + most surfaces
Virulence Factors
BACTERIAL INTOXICATION
- Heat-stable enterotoxin (Type-1 exotoxin = Super Ag)
-> Not destroyed by boiling
-> Toxin produced when bacteria incubate in food (temperature abuse)
Tissue/Organ Affected
- GI tract
Reservoir
- Human skin
Mode of Transmission
- Dirty hands with bacteria -> contaminated food -> bacteria make heat-stable enterotoxins (at room temperature)
Predisposing Factors
- x
Incubation Period
- Hours
SXS
(acute symptoms)
- FEVER (Type 1 exotoxin = Super Ag)
- Abdominal cramps
- Nausea
- Vomitting
- Diarrhea
Diagnosis
- x
Treatment
- Oral rehydration (cannot use ABX because ABX kill bacteria, but the problem is the toxin)
Preventative Measures
- Safe food handling
- Proper food temperature/refridgerate food
- Personal hygeine = wash hands
MISC
- x
Describe: Botulism
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Clostridium Botulism Intoxication/Foodborne Botulism
- CA: Clostridium botulinum
- Characteristics: Gram POSITIVE bacteria, bacilli, endospore-forming, obligate anaerobe
Virulence Factors
BACTERIAL INTOXICATION
- Potent, heat-labile neurotoxin (Exotoxin) = Low LD50
- Endospores (dangerous because during germination will become active cell and produce toxin)
Tissue/Organ Affected
- Nervous System
Reservoir
- Contaminated (canned) Food
Mode of Transmission
- Canned food with neurotoxins (anaerobic conditions)
Predisposing Factors
- x
Incubation Period
- x
SXS
- Toxemia (Ingestion of botulinum exotoxin; targets NS)
- Flaccid Paralysis (nerve damage = no muscle stimulation)
- Respiratory/Cardiac failure (death)
Diagnosis
- Culture body fluid (look for drumstick bacteria = presence endospore)
Treatment
- Respiratory assistance
- Antitoxins
Preventative Measures
- Commercial/proper canning methods
- Treat meats with nitrites (chemicals inhibits germination)
MISC
- Infant Botulism
-> Infant ingests C. botulinum spores = ingestion of honey
-> Weakened muscle tone (floppiness), trouble feeding - Wound Botulism
-> C. botulinum grows in deep puncture wounds (anaerobic condition)
-> Common IV drug users (goes deep into muscle)
Describe: Clostridium difficile - Associated Diarrhea
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Predisposing Factors, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: C. diff Colitis
- CA: Clostridium botulinum
- Characteristics: Gram POSITIVE bacteria, bacilli, endospore-forming, obligate anaerobe
Virulence Factors
BACTERIAL INTOXICATION
- Exotoxin
Tissue/Organ Affected
- Colon
Reservoir
- 1° = Humans
- 2° = Contaminated medical equipment
Mode of Transmission
- Fecal-contaminated water
- Contaminated medical equipment
Predisposing Factors
- Acquired in health-care settings (HAI)
- Extended use of ABX (destroys NM)
Incubation Period
- x
SXS
- Colitis: Ulceration/Perforation of intestinal wall
- Bloody/mild diarrhea (dysentery)
Diagnosis
- PCR (look for gene in stools that prod toxin)
Treatment
- Antiprotozoal drug (antiparasitic)
- ABX
Preventative Measures
- Disposable equipment in hospital setting (gowns, gloves, etc)
MISC
- ½ million infections/year
Describe: Salmonellosis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Salmonella Gastroenteritis
- CA: Salmonella enterica serovar Typhimurium
- Characteristics: Gram-negative bacteria, bacilli, motile, faculatative anaerobe
Virulence Factors
BACTERIAL INFECTION
- Multiplies in phagocytes = bacteremia
Tissue/Organ Affected
- GI tract (intestines)
Reservoir
- Contaminated poultry/fruits/vegetables
- Raw eggs
- Pet reptiles (turle, iguanas)
Mode of Transmission
- Contaminated food
Predisposing Factors
- x
Incubation Period
- Hours
SXS
- Fever (regular)
- Abdominal cramps
- Nausea
- Vomiting
- Diarrhea
Diagnosis
- PCR (look for DNA of pathogen)
Treatment
- Oral rehydration
- ABX
Preventative Measures
- Wash all fruits/veggies
- Avoid consumption raw eggs
- Avoid pet reptiles
MISC
- Chronic carrier: PT can shed bact. in feces for 6 months; still infectious
Describe: Typhoid Fever
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- CA: Salmonella enterica serovar Typhi
- Characteristic: Gram-negative bacteria, bacilli, motile, faculatative anaerobe
Virulence Factors
BACTERIAL INFECTION
- Multiplies in phagocytes = bacteremia
Tissue/Organ Affected
- GI tract (intestines)
Reservoir
- Humans
Mode of Transmission
- Fecal-contaminated water/food
Predisposing Factors
- x
Incubation Period
- Weeks
SXS
- PROLONGED, HIGH Fever
- Skin rash/Rose spots
- Ulceration/perforation = Bloody diarrhea/dysentery
- Muscle Aches
- Headaches
- Abdominal cramps
- Diarrhea
Diagnosis
- Visible SXS: Rose spots
- Pathogen in blood/stool sample
Treatment
- Oral rehydration
- ABX
Preventative Measures
- Personal hygiene = washing hands
MISC
- Small % of PT are chronic carriers = shed bacteria in feces
-> Require weeks treatment (ex: Typhoid Mary)
Describe: Shigellosis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Bacilliary Dysentery
- CA: Genus Shigella
-> Several species: S. felxneri, S. boydi, S. sonnei, S. dysenteriae (MOST VIRULENT)
- Characteristics: Gram-negative bacteria, bacili, fimbriae, facultative anaerobe
Virulence Factors
BACTERIAL INTOXICATION
- Shiga toxin
- Multiply in epithelial cell
Tissue/Organ Affected
- GI tract (intestines)
Reservoir
- 1° = Water
- 2° = Humans
Mode of Transmission
- Fecal-contaminated water
Predisposing Factors
- x
Incubation Period
- Hours to Weeks
SXS
- Colitis (inflammation of intestines)
- Bloody diarrhea (dysentery)
Diagnosis
- PCR (look for genes in stools that produces shiga toxins)
- Based on SXS
Treatment
- Oral rehydration
- ABX
Preventative Measures
- Personal hygiene = washing hands
MISC
- Dyesentery = severe nerve damage to intestinal mucosal lining = ulceration = blood mucous diarrhea
Describe: Bacterial Gastroenteritis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Mode of Transmission, SXS, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Pathogenic E. coli Gastroenteritis/Travelers Diarrhea
- CA: Enterotoxigenic E. coli (ETEC) strain
- Characteristics: Gram-negative bacteria, bacilli, motile, faculatative anaerobe, coliform bacteria
- WILL NOT LEAD TO DEATH
Virulence Factors
BACTERIAL INTOXICATION
- Enterotoxin (Exotoxin)
Tissue/Organ Affected
- GI tract
Reservoir
- x
Mode of Transmission
- Fecal-contaminated water by coliforms
Predisposing Factors
- x
Incubation Period
- x
SXS (less severe symtpms than E. coli O157:H7)
- Nausea
- Vomitting
- Diarrhea
Diagnosis
- x
Treatment
- Oral rehydration
- Bismuth-containing preparations (peptobismol)
- OTC antidiarrheal med
Preventative Measures
- Boiling water before consumption
MISC
- Coliform bacteria/Coliforms = E. coli found in GI tract of humans and animals
Describe: Hemorrhagic Colitis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Pathogenic E. coli Hemorrhagic Colitis, Shiga Toxin E. coli
- CA: Enterohemorrhagic E. coli (EHEC) strain (IS THE E. coli O157:H7)
- Characteristics: Gram-negative bacteria, bacilli, motile, fimbriae, facultative anaerobe, coliform bacteria
CAN LEAD TO DEATH
Virulence Factors
BACTERIAL INTOXICATION
- Shiga toxin (produced by E. coli O157:H7 as a result of Horizontal Gene Transfer)
Tissue/Organ Affected
- GI tract (intestines)
Reservoir
- Cattle
Mode of Transmission
- Fecal-contaminated food (ground beef)
Predisposing Factors
- x
Incubation Period
- x
SXS
- Colitis (inflammation of intestines)
- Ulceration/Perforation of intestinal lining = perfuse bloody diarrhea
- Hemolytic Uremia Syndrome (severe kidney damage = death)
Diagnosis
- PCR (look for genes in stools that produce Shiga Toxin)
Treatment
- Oral rehydration
- Supportive Care
Preventative Measures
- Routine meat inspection
- Proper cooking temperatures for ground beef (meat)
MISC
- Horizontal Gene Transfer: Shigella (donor cell) donates Shiga Toxin GENE to plasmid of non-pathogenic E. coli (recipeient cell) via conjugation pilus -> E. coli can now produce Shiga Toxins = E. coli O157:H7
- Few to hundreds death annually
E. coli O157:H7 strain is the causasive agent of what disease?
Describe how E. coli O157:H7 became pathogenic
How does it create symptoms of bloody diarrhea?
- Hemorrhagic Colitis
Because pathogenic because of:
- Horizontal Gene Transfer: Shigella (donor cell) donates Shiga toxin gene to plasmid of E. coli (recipient cell) via conjugation pilus -> E. coli now produces Shiga toxin= E. coli O157:H7
Shiga toxins damage intestinal mucosal lining = ulceration = blood enters GI tract = bloody diarrhea
Describe: Cholera
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- CA: Vibrio cholerae 01 or 0139 (2 strains)
- Characteristics: Gram-negative bacteria, slightly curved, bacilli, polar flagellum, motile
- Common in salty water (/fresh water)
Virulence Factors
BACTERIAL INTOXICATION
- Potent cholera exotoxin = Low LD50
Tissue/Organ Affected
- GI tract
Reservoir
- 1° = Water
- 2° = Humans
Mode of Transmission
- Contaminated water and seafood
Predisposing Factors
- x
Incubation Period
- x
SXS
- Large volume diarrhea
- “Rice water” stools (chunks of mucosal lining)
- Shock
- Circulatory Collapse
- Organ failure
Diagnosis
- x
Treatment
- Oral rehydration
- Electrolyte replacement
Preventative Measures
- Boil water
MISC
- Endemic to parts of Asia
- Associated with natural disasters
Describe: Brucellosis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Predisposing Factors, SXS, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Undulant Fever (temp goes up and down)
- CA: Brucella abortus
- Characteristics: Gram-negative bacteria, coccobacilli
- NOT FATAL
Virulence Factors
BACTERIAL INFECTION
- Multiply in phagocytes
Tissue/Organ Affected
- GI tract
Reservoir
- Livestock
- Wild animals (elk, bison, cow)
Mode of Transmission
- Unpasterurized milk from infected animals
- Contact with infected animals (zoonotic transmission/disease)
Predisposing Factors
- Dairy workers
- Leather makers
- Hunters
Incubation Period
- x
SXS
- Undulant fever = recurring, high fever
- Chills
- Night sweats
Diagnosis
- x
Treatment
- Prolonged treatment with ABX
Preventative Measures
- Vaccination of livestock/wild animals
- Pasturization of milk products
- Protective clothing
MISC
- Rare in USA
Describe: Hepatitis A
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- CA: Hepatitis A virus (HAV) - RNA
- Characteristics: Shed in feces (acute phase), survive on surface (several days), Resists chlorine treatment of water
Virulence Factors
- Multiply in epithelial lining (mucosa) or intestinal tract = viremia
Tissue/Organ Affected
- GI tract
- Liver
- Kidneys
- Spleens
Reservoir
- 1° = Food/water
- 2° = Humans
Mode of Transmission
- Contaminated food/water
Predisposing Factors
- x
Incubation Period
- Weeks
SXS asymp = children; symp = adults
- Juandice (LIVER; late stage DZ)
- Anorexia
- Nausea
- Diarrhea
- Headache
- Fever
- Chills
Diagnosis
- Serology: detection of antiviral antibodies; IgM
Treatment
- Injection of antibodies/immunoglobulins (artificially passive)
Preventative Measures
- Inactive HAV vaccine
MISC
- Not chronic/low mortality
- Life-long immunity after recovery
Describe: Viral Gastroenteritis (common in children)
(AKA/Causasive Agent, Tissue/Organs Affected, Incubation Period, SXS, Diagnosis, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Stomach Flu
- CA: Rotavirus - RNA
Virulence Factors
- x
Tissue/Organ Affected
- GI tract
Reservoir
- x
Mode of Transmission
- x
Predisposing Factors
- x
Incubation Period
- Days
SXS (1 week)
- Low-grade fever
- Vomiting
- Diarrhea
Diagnosis
- Viral antigens in feces
Treatment
- x
Preventative Measures
- Live oral vaccine
MISC
- Prevalent in winter months
- Common daycare centers
Describe: Viral Gastroenteritis (common in adults and children)
(AKA/Causasive Agent/Characteristics, Tissue/Organs Affected, Incubation Period, SXS, Diagnosis, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Stomach Flu
- CA: Norovirus - RNA
- Characteristics: Highly contagious = low ID50
Virulence Factors
- x
Tissue/Organ Affected
- GI tract
Reservoir
- x
Mode of Transmission
- x
Predisposing Factors
- x
Incubation Period
- Hours
SXS (days)
- Vomitting
- Diarrhea
Diagnosis
- PCR: look for genes (DNA) in stool
Treatment
- x
Preventative Measures
- Handwashing (no vaccine)
MISC
- Prevalent all year long
- Common on cruise-ships/classrooms = outbreaks
Describe: Poliomyelitis
(AKA/Causasive Agent, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Paralytic Polio
- CA: Poliovirus - RNA
Virulence Factors
- Multiply in motor neurons = viremia
Tissue/Organ Affected
- NS: motor neurons
Reservoir
- 1° = Water
- 2° = Humans
Mode of Transmission
- Fecal-oral route; contaminated water containing virus
Predisposing Factors
- x
Incubation Period
- x
SXS (mostly asymp)
- Lower-limb paralysis
- Respiratory failure (death)
- Sore throat (initial SXS)
- Nausea (initial SXS)
Diagnosis
- x
Treatment
- x
Preventative Measures
- Salk vaccine: injected; inactivated vaccine
- Sabin vaccine: oral; weak, live vaccine; lifelong immunity
MISC
- NO TREATMENT
- Common in children
- Viremia -> enters CNA -> multiply and destory motor neurons -> muscle wasting -> lower limb paralysis
- 99% decrease in cases from 1988 to 2000
Describe: Giardiasis
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Predisposing Factors, SXS, Diagnosis, Treatment, Preventative Measures)
AKA/Causasive Agent/Characteristc
- CA: Giardia intestinalis
- Characteristics: K. protista, SK. protozoa; flagellated protozoan parasite
Virulence Factors
- Multi-stage lifecycle
-> Dormant Cysts stage (water and feces)
-> Active Trophozoites attached to intestinal wall (humans)
Tissue/Organ Affected
- GI tract (intestines)
Reservoir
- 1° = Water
- 2° = Humans
Mode of Transmission
- Cyst contaminated water
Predisposing Factors
- Drinking from contaminated river stream
Incubation Period
- x
SXS
- PROLONGED Diarrhea
- Hydrogen sulfide gas (egg farts)
- Weight loss
- Cramps
Diagnosis
- Microscopic examination of stool samples (look for cysts)
Treatment
- Antiparasitic drug
- Antiprotozoal drug
Preventative Measures
- Boiling water
MISC
- x
Describe: Amoebiasis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Amoebic Dysentery
- CA: Entamoeba histolytica
- Characteristics: K. protista, SK. protozoa; protozoan parasite
Virulence Factors
- Multi-stage lifecycle
-> Dormant Cysts stage (water and feces)
-> Active Trophozoites attached to intestinal wall (humans)
Tissue/Organ Affected
- GI tract (intestines)
- Liver
Reservoir
- 1° = Water
- 2° = Humans
Mode of Transmission
- Cyst contaminated water
Predisposing Factors
- x
Incubation Period
- x
SXS
- Ulceration/Perforation intestinal wall (by trophozoites)
- Bloody diarrhea (dysentery)
- Necrotic liver abscess
Diagnosis
- Microscopic examination of trophozoites with ingested RBCs present inside
Treatment
- Antiparasitic drug
- Antiprotozoal drug
Preventative Measures
- Boiling water
MISC
- Deadly if left untreated
Define: Parasitology
What does it focus on studying?
study of parasites
limited to: Parasitic Protozoa, helminths (worms), anthropods
Generally define the Life Cycle of tapeworm infections
Describe the types of reproductions
continuous sequence of morphological changes undergone by an organism; part of reporoduction
Sexual reproduction: occurs in definitive/primary host
Asexual reproduction: occurs in intermediate/secondary host
Describe the area of prevalence of Tapeworm infections.
Where is it endemic to?
What can it become?
world-wide prevelance
endemic to Asia, Latin America, Eastern Europe
can become EID
Name the anatomy of a Beef Tapeworm and incude the function of each part
Scolex (head)
- Hooks: attachment
- Suckers: nutrient absorption
Cuticle (outercovering)
- Protection and nutrient absorption
Proglottids (Body segments)
- Highly developed reproductive system (male and female parts)
Describe: (Beef) Tapeworm Infection
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Misc.)
AKA/Causasive Agent/Characteristc
- AKA: Taeniasis (if infected with adult tapeworm)/Cysticercosis (if infected with cysticerci larvae by eating eggs)
-> Ophthalmic cysticercosis: larvae lodge in eye
-> Neurocysticercosis: larvar in CNS - if CA: Taenia saginata = Beef tapeworm infection
- Characteristics: Kingdom Animalia, Phylum Platyhelminthes
Virulence Factors
- Multi-stage lifecycle (long, complex)
- Eggs -> oncospheres -> cysticerci larvae -> adult tapeworm
Tissue/Organ Affected
- GI tract
Reservoir
- 1° = Humans (definitive host)
- 2° = Cattle (intermediate host)
Mode of Transmission
- Contaminated/undercooked beef
Predisposing Factors
- x
Incubation Period
- x
SXS
- Lack of appetite
- Abdominal Pain
- Weight Loss
- Fatigue
Diagnosis
- Stool sample - presence of eggs/proglottids (body segment)
Treatment (Prolonged use)
- Antiparasitic drug
- Antihelminthic drug
-> Will kill parasitic worm and eggs
Preventative Measures
- x
MISC
- Beef tapeworm = long and multiple segments
- Weeks to clear infection
- Tapeworm excreted as waste
What are the two hosts of a Beef Tapeworm Infection. Know if they are the definitive/intermediate host and what type of reproduction occurs
Humans - definitive host; sexual reproduction
Cattles - intermediate host; aasexual reproduction
Describe “Step #1” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.
Human (definitive host) is infected by eating raw/undercooked beef containing Cysticerci Larvae.
Sexual reproduction of tapeworm lifestyle happens in the human.
Describe “Step #2” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.
Cysticerci larvae will develop into an adult tapeworm in the human (definitive host) as a result of sexual reproduction (of the tapeworm lifecycle).
Scolex (head) containing hooks develops first so it can use the hooks to attach to the small intestine of the human (definitive host).
Describe “Step #3” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.
Mature proglottid (body segment so the adult tapeworm) containing eggs are passed in feces from the human (definitive host)
Sexual reproduction of the tapeworm lifecycle occurs in the human/definitive host
Prologttids disintegrate, leaving behind the eggs in the soil/environment
Describe “Step #4” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.
Cattle (intermediate host) is infected by eating contaminated food/grass containing the eggs.
Asexual reproduction part of the tapeworms lifestyle occurs here
Describe “Step #5” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.
Eggs in the cattle develop into oncospheres (infectious stage of tapeworm lifestyle)
Oncospheres hatch and the head (containing the scolex with hooks) develops first for attachment purposes
Describe “Step #6” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.
Cysticerci larvae develop and found in striated muscle of cattle
Cattle is slaughtered and infected meat is sold
Recall the developmental stages of the beef tapeworm (eggs -> oncospheres -> cystercerci larvae -> adult tapeworm)
Know which stages are present in the definitive or intermediate host, or both.
Cysticerci Larvae: definitive and intermediate (human and cattle)
Adult tapeworm: definitive (human)
Eggs: definitive and intermediate (human and cattle)
Oncospheres: intermediate (cattle)
Describe: Prion Disease
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Preventative Measures, Misc.)
AKA/Causasive Agent/Characteristc
- CA: Prions
- Characteristic: Infectious protein particles, abnormally folded
Virulence Factors
- Highly resistant
Tissue/Organ Affected
- Nervous System
Reservoir
- Cow
- Humans
- Sheep
Mode of Transmission
- Consumption of contaminated animal tissue
Predisposing Factors
- x
Incubation Period
- Years
SXS
- Progressive degeneration of brain tissue (spongiform encephalopathy)
Diagnosis
- x
Treatment
- x
Preventative Measures
- Incineration (burning)
MISC
- No treatment; CHRONIC AND FATAL
- Transmissible spongiform encephalopathy:
-> Mad Cow Disease
-> Crutzfeldt-Jakob disease
-> Sheep Scrapie
