Block 3-Parasites Flashcards

Question 1

Q

Protozoa General Properties

Answer

A

Single cells ^{(eukaryotic cell structure)}
Surrounded by either:
Plasma membrane ALONE
Combines w/Ext flexible pellicle ^{(extra protection/thin layer)}
Extracell or Intracell infections:
Trophozoite-motle, metab active, replicating form
Cyst-dormant, non-replicating form, adapted for survival in enviroment ^{(dormant in water or passed through feces)}
NO cyst form = transmitted via vector ^{(insect)} or direct contact ^{(sexual)}
Subdived depending on motility

Question 2

Q

Protozoa (4 groups)

Answer

A

Subclassed based on organelle movement
Unicellular & Trophozoite ^{(absorb nutrients from host)}
Amebae(sarcodina): Motile via pseudopods, divide by binary fission, exist as METAB active trophozoites & inactive as resistant cysts
Flagellates(Mastigophora): Motile via long whip-like flagella ^{(Tropho stage)}, divide by binary fission
Ciliates: motile short, brush like cilia, divide binary fission ^{(may conjugate)}, Exsist as trophozoites & cysts
Sporozoa(coccidia)-Reproduce by sexual/asexual means, exsist in diverse cellular forms (tropho, sporo, oocysts, gametocytes) NO means of locomotion intracellular

Question 3

Q

Metazoa/Helminths (2 groups)

Answer

A

Multicellular
Platyhelminthes has 2 sub groups
Nemathelminthes:
Round worms ^{(long white true alimentary tract)-}Oral to Fecal tract
- ^{oral attachment device}
- ^{produce egg & larvae}
Platyhelminthes: Flat worms
Cestodes-Segemented body ^{(proglottids-each segment contrains both male/female repro)}
- ^{Hermaphroditic}
- ^{Head has hooks or suckers attach}
Trematodes: leaf shaped, oral suckers, BLIND alimentary tract, can be Hermaphroditic ^{(Sexually self-reproduce)}

Question 4

Q

Trematodes/Flukes (general)

Answer

A

Small flat leaf like worms
Have suckers for attachment
Yolk gland
Gut
Testes & Uterus
Sexes of parasites are not sep(monecious) both sex organs - EXCEPT schistosoma
ALL use f_resh water snails as int host_

Question 5

Q

Cestodes/Segmented worms (general)

Answer

A

Ribbon like
NO GI tract-Food absorbed by host GI
Ant end-Scolex^{ (hooks/Suckers attach)}
Body-Strobila
Composed of proglottids
- ^{Repro structures filled w/eggs (have both)}
- ^{Break off & pass out of body into feces}
Pathogenesis-Adults are intestinal parasites & clinical signs are due to:
Sequestering host’s nutrients
Excreting toxic waste ^{(immune response)}
Massive infections ^{(Blockage of GI)}
Space occupying lesion^{(larvae in tissue)}
Some live for many years & tissue damage increases w/time

Question 6

Q

Nematodes (general)

Answer

A

Elongated, cylindrical, NON-segmented worms & tapered @ both ends
Have complete digestive system
Body covered by resistant coating=Cuticle
Seperate sexes:
Female make eggs
Eggs & larvae infect right away
OR require a period of development
Ifluenced by weather or soil type
MOST common in US=Pinworm (enrobiasis)

Question 7

Q

Protozoa/Entamoena Histolytica(GI)

Answer

A

Bio: Cyst has 4 nuclei and found in stool
Epidemiology: World wide, fecal-oral, Homosexual men
Symptoms:
Infection name -Ameobiasis
Intestinal (Large)-Dysentery Bloody diarhea
Liver can perforate through skin & brain abscess (no cysts seen)
Genital abscess (Homo)
Diagnose:
Cyst in stool
Tropho w/digested RBC inside seen from affected tissue (GI)
Treat: Metronidazole ^{(breaks DNA) }followed by idoquinol ^{(specific to protazoa)}

Question 8

Q

Protozoa/Giardia Lamblia (GI)

Answer

A

Flagellate exsist as Cyst ^{(2 nuclei)} & Trophozoite ^{(4 pair of flagella)}
Epidemiology:
world wide
infects many other animals
Contaminated water (streams, Rivers) Travel or Hiking
Food & fingers/Day Care
Symptoms of infection-_Giardiasis_
Adhere to small intestine
Food malasbsorption ^{(Fats & Fat-sol Vit)}
GI-NONbloody diarrhea-Bulky & Greasy stools
_Diagnose: _
Cyst do NOT release right away several stool samples needed
String test w/gelatin capsule shallowed traps tropho in small intestine
Treatment: Metronidazole ^{(breaks DNA)}

Question 9

Q

Protozoa/Cryptosporidium Parvium (GI)

Answer

A

Bio: Sporozan ^{(no means of locomotion intracellular)} exit in diff forms
adheres to epithelia cells of SI ^{(tropho)}
*Acid fast oocyst *
Epidemiology: World wide, infects animals-oral/fecal route
Symptoms:
AIDS assoc diarrhea ^{(immuno-comprimised)}
Non-bloody
Chronic up to 50 stools a day
_Diagnose: _
Oocyst in feces ^{(Sporoziotes inside)}
Acid fast staining UNIQUE
Treatment: self limiting in Healthy people
No effective treatment for immunocomprimised pts (deadly)

Question 10

Q

Protozoa/Balantidium Coli (GI)

Answer

A

Bio: Ciliated ^{(motile/short)}, Cyst & Tropho, 2 nuclei ^{(mega & micro)}
Epidemiology: World wide, infects animals **(PIGS)-Farmers risk factor **
Symptoms of Entamoeba histolytica dysentery & Bloody diarrhea
_Diagnose: _
Cyst = No cilia w/2 nuclei (Micro/Mega)
Tropho = Cilia w/2 nuclei (Micro/Mega)

Question 11

Q

Protozoa/Trichomonas Vaginalis (Urinary)

Answer

A

Flagellate (4 anterior)
Exsist as Trophozoite ONLY
Binary fission
Epidemiology: World wide-Sexual transmission OR **sharing shower materials **
Symptoms of Trichomoniasis:
Female:
Inflammation of vagina & cervix w/itching, burning ^{(Strawberry red cervix)}
Small amount of Vaginal discharge-Frothy & greenish-yellowish
Male:
Resevior^{ (harbor parasite w/no symptoms)}
Small amount of urithritis w/discharge
_Diagnose: _
Flagellate in vaginal & urethral discharge
Treatment: Metronidazole ^{(DNA break)}

Question 12

Q

Protozoa/Plasmodium Sporozoan (Blood)

Answer

A

May exsist in different forms
Sexual & asexual reproduction
Sporozoites = Infective to Liver cells
Trophozoites = early stages of infecting RBCs ^{(Actively dividing)}
Merozoites = When Schizont bursts can infect RBCs as Trophozoites
Schizont = RBCs & liver
Epidemiolgy: Tropical/Subtropical, vector born (Mostquito)
_Symptoms: _
Intracellular parasite: Infects RBCs & Hepatocytes (Dorment here)
Malaria: Fever, chills, sweating (cycle)
Heptosplenomegaly & anemia
Cerebral malaria & Black water fever (dark urine) = Falciparum

Question 13

Q

Protozoa/Plasmodium Sporozoan (Diagnosis)

Answer

A

Blood sample: Shows ring form or Gamete form
P. Falciparum is UNIQUE
due to multiple ring & Crescent shape Gamete
All other malarias except Falciparum can be dormant in liver
Everytime RBCs rupture together it is in a 24-72 hour cycle = Fever/Sweating
Falciparum is every 24 hours
Ovale is every other day
Humans are intermidiate host for mosquitos^{ (no sexual maturation)}

Question 14

Q

Protozoa/Babesia Microti (Blood)

Answer

A

Babesiosis
Morphology: Sporozoan, can exsist in diff forms, Sexual/Asexual repro
Epidemiology: Found in same area as borrelia burgdorferi (lyme disease) Northeast US
Reservoir: Rodents
Transmitted by-
Ticks (Ixodes Dammini)
Human to Human in Blood transfusions
Symptoms:
Infects RBCs NOT liver
Malaria like symptoms ^{(fever/chills)}
Can be fatal in aspelnic pts or immunocomprimised pts
Diagnosis: Maltese cross or Tetrad formation ^(Merozoite) in thin blood smear

Question 15

Q

Protozoa/Toxoplasma Gondii (Tissue)

Answer

A

Morphology: Sporozoan, Sexual/Asexual reproduction
Epidemiology: World wide w/2 Hosts-
Definitive Host-Cats ^{(reproduction of Parasite)}
Intermediate Host-Man,cattle,rodents ^{(Limited growth of parasite)}
Transmitted-Cat feces, consumption of meat w/cyst & Transplacental
_Symptoms of Toxoplasmosis: _
Intracellular parasite: Infects macrophages,muscle cells,epithelial cells ^{(variety of tissues) =} Affects many organs
Severe in immunocomprimised pts (AIDS)-Neuro effects common
Cong. infection: can lead to abortion, still birth or cong defects ^{(Intracranial calc)}, blindness^{(choroiditis)} ^{(1/3 of infection goes to fetus)}

Question 16

Q

Protozoa/Toxoplasma Gondii-Diagnosis

Answer

A

Blood sample:
IgM present in acute infection & in new born
Trophozoite stage: Crescent shape w/prominent cetral nucleus
Cysts are visible in tissues (muscle, brain,etc..) Stained w/Hematoxyin & eosin

Question 17

Q

Protozoa/Leishmania Sp. (Tissue)

Answer

A

Morphology: Flagellate (promoastigote IN tissue) & non-flagellate form (Amostigote OUT of tissue)
4 species:
L. donovani = Kala-azar (Visceral)
L. tropica = Cutaneous
L. mexicana = Cutaneous
L. braziliensis = Mucocuteneous
Epidemiology: World Wide w/restricted distrubution ^{(Favor arid, dry, warm)}
Infects: Dogs & rodents
Transmitted by: Sand fly ^{(phlebotomus)}
Symptoms: Multiply inside macrophages
Kala-azar: affects organs of reticuloendothelial system ^{(spleen/liver/BM)}
Cutaneous ulcerating skin ^{(appear and heal)}
Mucocutaneous lesions(worse)

Question 18

Q

Protozoa/Leishmania Sp. (Diagnosis)

Answer

A

Microscopic w/Biopsy:
Bone marrow
Spleen
Liver
Lymph node
Lesions demonstrate parasites inside macrophages
Blood sample
Culture phagocytosed by macrophages
Skin test = Leishmanin test use Ag to get rxn

Question 19

Q

Protozoa/Trypanosoma African sleeping sickness (Tissue)

Answer

A

Morphology: Flagellate
African Sleeping sickness-
Trypanosoma brucei gambiense
Trypansoma brucei rhodesisnse
Epidemiology: Trasmitted by Glossina (fly) found in open grassland
^{Tb Gam = Human is main host}
^{Tb Rhon =Human,cattle,Antelope}
Symptoms-Extracellular
Binary fission Multiply in body fluids ^{(blood,lymph,CSF)}
Lesion @ site of insect bite
Intmittent fever occurs in cycle every 2 weeks
Splenomegaly, myocarditis, leukocytosis, thromcytopenia, anemia
Involvement of CNS = Terminal
Diagnose: Blood smear or Spinal Tap

Question 20

Q

Protozoa/Trypanosoma Cruzi (Tissue)

Answer

A

American/Chagas disease
Morphology: Exit as flagellate & NON
Epidemiology: Infects humans, cats, dogs, rats, raccoon, Armadilla/opossums
Transmitted:
insect vector-
(Rediviid) feeds & defactes on wound ^{(parasite enters through bite by rubbing)}
Find them in cracks of mud huts
across placenta
U.S. Organ/blood transplant
Seen in central & south America
_Diagnosis: _
Infection happens @ bite (chagoma)
Causes periorbital edema^{(Romana’s sign-Unilateral swelling of eyelid)}
Blood sample = Flagellate
Tissue boipsy = Amastigote form
Xenodiagnosis = Isolate parasite from infected host by letting bugs feed

Question 21

Q

Protozoa/Trypanosoma Cruzi (Symptoms)

Answer

A

Symptoms-Tissue:(common in latin America)
invade and multiply inside-
smooth muscle
ganglion cells in organs^{(heart, GI, skeletal muscle)}
Acute phase: Lesion (chagoma) @ site of inoculation^{ (fever, lymphadenopathy)}
Latent phase: No symptoms (last for years)
Chronic phase: Many years later muscular degeneration & denervation of GI/Heart
^{Megaesophagus, Megastomach,Megacolon}
^{Cardiac arrythemias = reduced HR}

Question 22

Q

Protozoa/Naegleria fowleri (CNS)

Answer

A

Morphology: Amoeba exsist as 1.cyst,2.trophozote & 3.flagellated form
Fowleri is the only Naegleria that infects humans
Reservoir: Found everywhere in nature
Warm water ^{(heated pools, hot tubs)}
Sewage Major-source of warm water
Transmission: Acquired in summer from contaminated lakes ^{(Hot tubs)}
Via nose (olfactory mucosa/Tissues) through here it can reach BRAIN
Most @ risk young children
Prevention: Avoidance
Treatment: Largely ineffective so early diagnosis CRITICAL

Question 23

Q

Protozoa/Naegleria fowleri (Symptoms)

Answer

A

Symptoms: “Brain-eating ameoba”
1st signs flu-like symptoms
PAM ^{(primary amebic meningitis)} w/Olfactory hallucinations ^{(smell things that aren't there)}
Granulomatous encephalopathy
Severe headaches, fever, vomiting, focal neurologic deficits
Rapid-ONSET (less than 10 days)
Coma to DEATH
Diagnosis: Find in CSF or Nasal discharge
Wet mount can detect motile trophozoite
Giemsa-stained
Florescent stain (use Ab specific)

Question 24

Q

Protozoa/Acanthamoeba Castellani (Visual)

Answer

A

Morphology: Free living amoeba
Epidemiology: Found everywhere in nature, Warm bodies of water (Hot Tub)
Transmission: Direct contact w/contaminated H2O through damaged skin OR corneal abrasion
Symptoms:
Keratitis(Cornea inflammed)- Assoc w/contact lens or eye trauma
Granulomatous amoebic encephalitis
Disseminated cutaneous & subcutneous infection in HIV pts or immunocomp
No good treatment except avoidance

Question 25

Q

Cestatodes/Diphyllobothrium Latum (Fish)

Answer

A

Morphology: Up to 25m long, operculated Egg
Epidemiology: Worldwide, Cool lake regions-freshwater ^{(animal reservoirs)}, Intermediate host crustacens & Fish
Transmission: ingestion of raw undercooked FRESH salmon or canned
Symptoms (can live up to 25 years)
GI-Mild discomfort, bloating, diarrhea ⁽
Migrating proglottids-
^{Acute ab pain & intestinal obstruction}
^{Cholangitis} ^{(inflammation & obstruction of bile ducts = cholecystitis)}
Megablastic anemia^{-}Vit B12 def^{(parasite absorbs)}
Neurological sequelae due to Vit B def
Diagnose: Large PMN with multiple discrete nuclear lobes^{ (megablastic)} Or eggs in feces

Question 26

Q

Castatodes/Echinococcus granulosus (Dog)

Answer

A

Hydatid or Hydatidosis
Morphology: 3 proglottids, form tissue cyst
Epidemiology: World-wide, human is accidental host, Definitive host=Dog & Intermediate host=Sheep
Transmission: Fecal-oral ^{(food,water, fingers w/dog feces)}
Symptoms: ^{make cysts (larvae) in tissue}
Larvae grow = destruction = Lesion
Type 1 rxn = leakage of germinative membrane = Anaphylaxis ^{(shock&death)}
Daughter cysts escape to other organs
Cysts grow develop 5-30 years Most common is liver 2nd to lung
Pressure on organs = ^{Scarring & loss of Fxn}
Cysts calcify rupture & disseminate
DIagnose: X-rays, CT, MRI (imaging), Blood detects Ag

Question 27

Q

Cestatodes/Taenia saginata (Beef)

Answer

A

Only 1 worm per person
Epidemiology: WW, intermediate host=Cattle & Definitive host=Human
Transmission: undercooked or raw beef
Symptoms of Taeniasis
Mostly asymptomatic
Mild vague ab pain or discomfort
Annoynace^{passive defication of 1-6 proglottids}
Proglottids can come out around anus
Diagnosis: Detected by proglottids in stool
Distinct fluid filled cystericercus
Prevention: Cook beef & wash utensils after cutting raw meat

Question 28

Q

Cestataodes/Taenia Solium (pork)

Answer

A

Epidemiology: WW, Pigs=Intermidiate host ^{(eat grass with eggs can survive for months)} Human = Intermidiate/Definitive host
Transmission: Undercooked pork or autoinfection^{ (Fecal-oral)}
**Recurge of eggs from GI to stomach allow them to hatch **
Symptoms-Adult lives in intestine & larvae (cyst) found in many tissue
GI: infections are asymptomatic w/mild ab-discomfort
Cysticerciosis: Space occupying lesion
Immune response when cyst dies
Symptoms depend on where cyst is:
Brain = seizures, headaches, vomiting
Spinal cord = paralysis
Eyes = blindness
DIagnose: CT, MRI, biopsy w/Larvae seen

Question 29

Q

Tremadotes/Clonorchis sinensis (Liver)

Answer

A

Epidemiology: Oriental region, Fresh water Fish or snail = Intermediate host
Trasmitted: Eating raw/undercooked freshwater fish which were infected by: ^{Cercariae & Metacercariae are in flesh of fish}
Symptoms: ^{can happen over 10-20 years}
adults live in BILE DUCT = inflammation w/fibrosis & hyperplasia
Narrowing/Blockage occurs=Jaundice
Heavy infections of eggs = Liver granuloma, Edema, ascites & diarrhea
GI discomfort & loss of weight
Diagnosis: ID of eggs in stool
Prevention: Avoid raw, pickled, smoked fish

Question 30

Q

Tremadotes/Paragonimus Westermani (lung)

Answer

A

Epidemiology: WW
Transmitted: Eating Raw/undercooked crab which are infected w/Cercariae
Snails 1st intermediate host^{ (life cycle)}
In humans cercariae encyst=^{Metacercariae}
Symptoms of Lung fluke:
Start off in Duodenum and go through diaphragm to infect pleura
Long term = Pulmonary fibrosis ^{(0.5 no O2)}
Symptoms can appear as TB
Pleurisy ^{(Inflammation of pleura)}=Pulm pain
chronic bad/dry cough w/blood in sputum (Rusty brown)
Other ectopic infections can occur Brain, SC, & GI
GI = diarrhea & ab pain
Brain = visual disturbances, headaches, serious cases embolisms and epilepsy
Diagnose: ID eggs in sputum/Stool & Xray
Treatment: Praziquantel ^{(specific anti-parasite)}

Question 31

Q

Trematodes/Schistosoma spp (Blood)

Answer

A

Schistosoma mansoni/Japonicum
Morphology: Sexes seperate ^{(male & female attached to eachother)}=Ensures fertilization
Snail intermediate host ^{(larvae)}
Epidemiology: WW, affects millions, associated w/water resource development projects ^{(dams/irrigation)}
ex. Workers in rice fields
Transmission: Penetrate skin by cercariae
Symptoms: Adults live in urinary or mesenteric BV-GI ^{(live 10-25 years)}
3 sub-species
(Mesenteric Blood humans, baboons, rats)
Schistosoma haematobium- lives in veins draining bladder (HUMAN HOST ONLY)

Question 32

Q

Trematodes/Schistosoma spp (Diagnosis)

Answer

A

Acute phase: Swimmer’s itch-w/in 12 hrs
Immune rxn to penetrating cercariae
Pruritus ^{(itchy skin)} or urticaria ^(hives)
2-3 weeks fever & chills
Chronic phase: Presence of eggs
Formation of granuloma
Production of proteolytic enzymes by eggs
Organs most affected:
Liver-Periportal fibrosis = portal hypertension^(ascites)=hepatosplenomegaly
Bladder-granulomatous, lesion, hematuria, urethral occulsion (BLADDER CANCER)
GI-cause polyp formation, severe cases life threatening dysentery^{(bloody, mucus feces)}
Diagnosis: Egg in urine/stool or serology (ELISA)
Prevention: Destroy snail habitat by clearing water plants (breed on vegetation)

Question 33

Q

Trematodes/Schistosoma (Slide ID)

Answer

A

Paired adults men are bigger and females are slender
_S. Manosni = Live in mesenteric _
Eggs Found in feces & Urine
Oval shape w/small bud (spine)
S. Japonicum = Live in mesenteric
Eggs found in feces & Urine
Circle shape NO buds
S. Haematobium = Live in Bladder
Eggs found in Urine
Oval shape w/NO bud

Question 34

Q

Nematodes/Enterobius vermicularis (Symptoms)

Answer

A

“Pinworm”
Epidemiology: World wide & most common in US
Transmission: Fecal-oral, Cold weather, Small children No animal reservoir (human-human)
Symptoms: Type 4 immune rxn to secretion of female, excoriation (flaking of skin)
Severe itching-Perianal & vaginal irritation by female laying eggs/Larvae=Insomnia
Secondary infection-Due to scratching
GI-Pain, nausea
Adult worm enters appendix or genital tract^(female) = granuloma
Eosinophila & elevated IgE seen
Retroinfection migration of newly hatched larvae from the anal skin back into rectum

Question 35

Q

Nematodes/Enterobius vermicularis (Diagnose)

Answer

A

Pin Worm
ID: Scotch tape test-adult worm & eggs can be recovered (20,000+)
Eggs mature in an oxygenated-moist enviroment & survive 2-3 weeks outside
eggs are thin walled & falttened
Treatment:
2 doses to treat adults and then eggs=Very high cure rate
Whole families should be treated to prevent reinfection
Bedding & underwear sanitized between 2 treatments

Question 36

Q

Nematodes/Trihuris trichiura

Answer

A

“Whip worm”
Epidemiology-World wide children greater risk (Southeast in US & poor countries)
Mostly asymptomatic
Infections are serious
Chronic profuse mucus & bloody diarrhea w/ab pain - Prolapsed rectum (worms)
Can result in malnutrition, anemia, growth retardation
Larvae hatch in GI
Adults in cecum
Unembroynated eggs in feces
Diagnosis-Unembroynated eggs in feces, lemon color & barrel shaped (bipolar plugs)

Question 37

Q

Nematodes/Ascaris Lumbricoides (diagnosis)

Answer

A

LARGEST NEMATODE
Epidemiology: WW-common w/poor sanitation, eggs survive in nature, thrive in feces & sewage
No animal reservoir ^{(some pigs can infect)}
Human-Human - ex. Pig farmer
Transmission: ingestion of eggs
1/4 of world’s pop has infection
Tropical & subtropical (SE USA)
Egg hatches in GI->carried into portal circulation->lung (further develop)->work up the trachea to shallowed->back to GI
2nd trip to GI = Adult worm
Diagnosis:Thick walled Fert egg & Thin wall Unfert egg
Stool-eggs (knobby) and occasionly adults
Sputum or gastric content larvae
Imaging study: Patchy infiltrate on X-ray or Adults seen in Ab X-ray

Question 38

Q

Nematodes/Ascaris Lumbricoides (symptoms)

Answer

A

Pulm: Pneumonitis (asthma-like)
Caused by larvae in lungs
Larvae brings eosinophils=Accumulation
Dry NON-productive cough
Chest pain
Wheezing/Rales
Chest X-ray shows WBC/eosinophils infil
GI: Mech irritation vague pain
Heavy infection=Large # of parasites
Small bowel obstruction (children)
Perforation (bleeding)
Intussusception (telescope-like fold)
Volvulus (bowel twist on itself)
Adult worm migration-
Bile duct leads to cholecytitis
pancreatic duct leads to pacreatitis

Question 39

Q

Nematodes/Ancylostoma Duodenale

Answer

A

Hookworm & Necator Ameri
Epidemiology: WW, warm, shady, sandy soil
Transmitted: Direct penetration of skin by LARVAE in soil
Filariform larva infects barefoot
Skin->Circulation->Lung->Trachea->GI
In GI they mature
Skin-Ground itch @ site of penetration
Pulm: migrating larvae
GI: Anorexia, PICA, Ulcer-like symptoms,Diarrhea
Anemia due to perferation=chronic blood loss (worm secretes anti-coag)
Children suffer retardation ^{(mental&physical)}
Diagnosis: eggs in stool (thin walled)
A. duodenle has chitnous teeth

Question 40

Q

Nematodes/Strongloides Stercoralis (diagnosis)

Answer

A

Thread Worm
Epidemiology: Tropical/Subtropical & poor sanitation
Warm moist soil
Sporadic cases in temperate regions
Transmission: penetration through skin(hookworm) + Autoinfection (YEARS)
Life cycle:
Free living cycle (Adult worms)
Skin penetration (Infective filarform larvae)
Auto-infection w/o leaving host (Rabditiform larvae become Filariform)
Diagnosis: Larvae NOT eggs in stool or sputum

Question 41

Q

Nematodes/Strongloides Stercoralis (Symptoms)

Answer

A

Thread worm
Ground itch-site of penetration
Migratory larvae-Larvae currens is slow/wavy progressive (rash)
Pulm: Pneumonitis- migrating larvae
Cough, dyspena, wheezing (asthma-like)
GI: Cramping, chronic bloody diarrhea
Hyperinfection = autoinfection reaccuring episodes for years
Disseminated storgloidiasis:
In immunocompromised pts
Same symptoms-lead to shock/death

Question 42

Q

Nematodes/Trichinella Spiralis

Answer

A

Trichinellosis
Epidemiology: WW, infects variety of animals (carnivores/Omnivores)
Rare in tropics
Pig MAIN source for humans
Transmission: Undercooked meat (pig/bear)-Larvae embedded in muscle
Adults intestine & Larvae in muscles
Host has rxn with LARGE # of larvae due to their metabolites
Muscles become enlarges & deformed
Neutrophils, eosinophils, lympho can PARALYZE muscle
Symptoms: GI & Fever* (first 3 days)*
mytositis, periorbital edema, myocarditis
Neuro-_vertigo & Tinnitus_(14-28 days)
Treatment: Cant reach larvae in tissue-Steroids for inflammatory
Diagnosis: encyted worms in muscle biopsy (spiral-look)

Question 43

Q

Nematodes/Toxacara canis or T. cati

Answer

A

Dog & Cat parasite like Ascaris Humans are dead end host
Transmission: Ingestion of eggs from dog/cat feces
Larvae from GI wonders in different organs & disintegrate = inflammatory response, granuloma, tissue damage
Migrate-Lungs, liver, hear, kidneys, brain
Symptoms (depend on what organ):
GI: 1st manifestation fever, anroexia, pain
Pulm: coughing & wheezing
Blindness
Death occurs due to resp failure, cardiac arrthymias or brain damage
Diagnosis: Biopsy of affected tissue larvae

Question 44

Q

Nematodes/Ancylostoma caninum & Braziliense

Answer

A

Dog & Cat Hookworm
Larvae penetrates human skin
Migrates under skin
Induced strong Anti-inflammatory IgE
Children exposure to soil w/pet’s feces
Symptoms:
Cutaneous larva migrans (creeping eruption)
Extremely itchy
Lasts 2-10 weeks
Seen mostly on lower extremities due to entry

Question 45

Q

Nematodes/Flilarial Elephantiasis

Answer

A

Tropical/sub-tropical transmitted by mosquitos @ night
Chronic & Debiltating
Acute: Fever, inflammation of lymphs
Chronic: Lymph nodes enlarge=Obstruction of lymph vessels
Edema in extremities
Stretched skin susceptible to traumatic injury=Bacterial infections
Diagnosis=Larvae (microfilariae) in blood

Question 46

Q

Nematodes/Onchocerca Volvulus

Answer

A

Onchocerciasis (River Blindness)
Africa & central/south america
Transmitted: by black flies simulim damnosum found along rivers & springs
Symptoms: Eye, skin & lymph
Immune rxn is to migrating microfila
Ocular: Larvae go to cornea
Chronic infection leads to keratitis-area goes opaque = Blindness
Skin: nodules form Onchocercomata
Adults found here
Intense itching & swelling
Lizard skin = keratinized
Lepard skin = depigmentation of ant leg
Lymph: hanging groin
Inguinal & femoral area enlarged
Ivermectin kills Larvae ONLY
Suramin kills adult worms quite toxic

Question 47

Q

Nematodes/Dracunlus medinensis

Answer

A

Guinea worm or feiry serpent
Tropical Africa
Transmission: Water containing Copepod, cyclops
Impregnated females move under skin of legs, ankles or feet-Forms lesion (HOLE)
Prevention:
Filter drinking water using a fine mesh
Ground water
Expected to extinct in near future

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