Food and Waterborne Diseases Flashcards

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1
Q

feve

Foodborne and Waterborne diseases involves the…

A

fecal-oral route

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2
Q

Compare a Bacterial Infection from Bacterial Intoxication
(whats consumed, why is it dangerous, incubation period, s/sx)

A

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

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3
Q

Describe: Staphylococcal Food Intoxication
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Treatment, Preventative Measures)

A

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

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4
Q

Describe: Botulism
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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)
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5
Q

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.)

A

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

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6
Q

Describe: Salmonellosis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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

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7
Q

Describe: Typhoid Fever
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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)

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8
Q

Describe: Shigellosis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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

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9
Q

Describe: Bacterial Gastroenteritis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Mode of Transmission, SXS, Treatment, Preventative Measures, Misc.)

A

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

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10
Q

Describe: Hemorrhagic Colitis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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

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11
Q

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?

A
  • 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

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12
Q

Describe: Cholera
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Treatment, Preventative Measures, Misc.)

A

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

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13
Q

Describe: Brucellosis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Predisposing Factors, SXS, Treatment, Preventative Measures, Misc.)

A

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

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14
Q

Describe: Hepatitis A
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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

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15
Q

Describe: Viral Gastroenteritis (common in children)

(AKA/Causasive Agent, Tissue/Organs Affected, Incubation Period, SXS, Diagnosis, Preventative Measures, Misc.)

A

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

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16
Q

Describe: Viral Gastroenteritis (common in adults and children)

(AKA/Causasive Agent/Characteristics, Tissue/Organs Affected, Incubation Period, SXS, Diagnosis, Preventative Measures, Misc.)

A

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

17
Q

Describe: Poliomyelitis
(AKA/Causasive Agent, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Preventative Measures, Misc.)

A

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

18
Q

Describe: Giardiasis
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Predisposing Factors, SXS, Diagnosis, Treatment, Preventative Measures)

A

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

19
Q

Describe: Amoebiasis
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Preventative Measures, Misc.)

A

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

20
Q

Define: Parasitology
What does it focus on studying?

A

study of parasites
limited to: Parasitic Protozoa, helminths (worms), anthropods

21
Q

Generally define the Life Cycle of tapeworm infections

Describe the types of reproductions

A

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

22
Q

Describe the area of prevalence of Tapeworm infections.
Where is it endemic to?
What can it become?

A

world-wide prevelance
endemic to Asia, Latin America, Eastern Europe
can become EID

23
Q

Name the anatomy of a Beef Tapeworm and incude the function of each part

A

Scolex (head)
- Hooks: attachment
- Suckers: nutrient absorption

Cuticle (outercovering)
- Protection and nutrient absorption

Proglottids (Body segments)
- Highly developed reproductive system (male and female parts)

24
Q

Describe: (Beef) Tapeworm Infection
(AKA/Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, SXS, Diagnosis, Treatment, Misc.)

A

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
25
Q

What are the two hosts of a Beef Tapeworm Infection. Know if they are the definitive/intermediate host and what type of reproduction occurs

A

Humans - definitive host; sexual reproduction
Cattles - intermediate host; aasexual reproduction

26
Q

Describe “Step #1” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.

A

Human (definitive host) is infected by eating raw/undercooked beef containing Cysticerci Larvae.

Sexual reproduction of tapeworm lifestyle happens in the human.

27
Q

Describe “Step #2” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.

A

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).

28
Q

Describe “Step #3” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.

A

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

29
Q

Describe “Step #4” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.

A

Cattle (intermediate host) is infected by eating contaminated food/grass containing the eggs.

Asexual reproduction part of the tapeworms lifestyle occurs here

30
Q

Describe “Step #5” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.

A

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

31
Q

Describe “Step #6” of the Beef Tapeworm Lifestyle. Be able to identify the stage when given the visual reference of the life cycle.

A

Cysticerci larvae develop and found in striated muscle of cattle

Cattle is slaughtered and infected meat is sold

32
Q

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.

A

Cysticerci Larvae: definitive and intermediate (human and cattle)
Adult tapeworm: definitive (human)
Eggs: definitive and intermediate (human and cattle)
Oncospheres: intermediate (cattle)

33
Q

Describe: Prion Disease
(Causasive Agent/Characteristic, Virulence Factors, Tissue/Organs Affected, Reservoir, Mode of Transmission, Incubation Period, SXS, Preventative Measures, Misc.)

A

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