Parasites Flashcards
1
Q
Endoparasite
A
Lives within the host
2
Q
Ectoparasite
A
Lives on the surface of body
3
Q
Organisms classified as parasites are usually? Two categories?
A
Eukaryotes (Protozoa and Metazoa)
4
Q
Protozoa
A
Unicellular
5
Q
Metazoa
A
Multicellular
These are branched into anthropoids and helminiths (round and flat worms)
6
Q
Flat worm divisions?
A
Flukes and Tapeworms
7
Q
Most protozoa and metazoa are ______ and seldom are an inconvience to the human race. Minority = parasites of humans/other vertebrates. Disease-causing species are typically OBLIGATE PARASITES, dependent on vertebrate and/or anthropoid hosts to live in.
A
Free-living
8
Q
Increased risk for parasitic disease?
A
Third world, travelers, impoverished, sexually active, immunocompromised
9
Q
Protozoa transmission?
A
insect, fecal-oral, sex
10
Q
Metazoa transmission?
A
macroscopic penetration of barriers (or insects)
11
Q
What plays a role in helminth infections?
A
IgE (early role)
Degranualtion of basophils and mast cells is due to IgE response. Histamine is released as well as others. Helps to recruit ore inflammatory cells.
12
Q
What participates in killing of antibody coated parasites (IgE)?
A
Eosinophils.
13
Q
Techniques for parasitic infections?
A
- history taking
- imaging
- laboratory techniques (definitive)
14
Q
Death categories from parasites?
A
Helminths
Malaria
Schistosomiasis
Entamoeba histolytica
15
Q
Sudden attack in malaria is described as what…?
A
paraoxysm
16
Q
Malaria Most deadly? How to diagnose? What does it look like?
A
Plasmodium Flaciparum
Blood test is used to diagnose
Looks like a ring in the RBC
17
Q
Vector for Malaria?
A
Anopheles mosquito
18
Q
What family is the plasmodium falciparum apart of? What is their asexual reproduction called?
A
- Sporozoa class (technically a protozoa - unicellular)
- Schizogony (sporogony) = asexual reproduction in RBCs where the nucleus undergoes division before cell division (unique)
19
Q
What phylum is the plasmodium flaciparum in? What other types of parasites does it include?
A
Phlyum = Apicomplexa
Includes:
- Cryptosporidium parvum (causes severe diarrhea in AIDS pts, tranmitted via cyts in H20)
- Toxoplasma gondii - COMMON - (brain abscess [aids] and brain damage [newborn], raw meat transmits cysts
20
Q
TORCH used when?
A
NEONATAL JAUNDICE - INFECTIOUS ETIOLOGIES
Used for several perinatal infections that are vertically transmitted from mother to offspring and associated with congenital anomalies, rash, hepatosplenomegaly, jaundice, and other changes
21
Q
TORCH stands for…?
A
Toxoplasmosis Other (syphilis, varicella-zoster, parvovirus B19) Rubella Cytomegalovirus (CMV) Herpes
22
Q
Definitive Host
A
host where the parasite reproduces sexually (ex. mosquito in malaria)
23
Q
Intermediate Host
A
host where the parasite reproduces ASEXUALLY or undergoes larval development (ex. human in malaria)
24
Q
Steps in Malaria
A
- Mosquito takes a blood meal (injects sporozites).
- Infected Liver cell - Liver cell bursts.
- Human blood cell infected (ring stage). - SEE SYMPTOMS HERE. Matures in RBC and causes it to burst.
- Creates gametes in RBCs that can be taken up by another mosquito.
- Fertilization happens in mosquito through sexual reproduction.
25
Symptoms of Malaria?
Cycling fever due to lysing of RBC; periodicity = 48 hrs
26
Diagosis/Tx for Malaria?
Diagnosis = blood smear
Tx = chloroquine; Artemisinin therapy if resistant
Use nets/pesticides
27
Plasmodium falciparum is deadly but what is one thing that is good about it?
doesn't remain dormant in liver; aka eradicating the RBC contained form = curative
28
P. vivax and P. ovale infections... what is unique about them?
Remain dormant in liver as "hypnozoite" (sleeping animals) and they can have a relapsing infection even if you eradicate the RBC forms
29
What medication should be used for P. vivax and P. ovale dormant liver forms?
primaquine to clear liver forms
30
miricidia - seen in schistosoma mansoni
a free-swimming ciliated larval stage in which a parasitic fluke passes from the egg to its first host, typically a snail
31
Schistosoma Mansoni picture
View slide!! - Has an egg inside (egg meaning embryo - zoology egg)
32
Schistosoma mansoni is what type of parasite? Intermediate host? Nick name for schistosoma species?
flatworm
snail
blood flukes
33
Symptoms of schistosoma mansoni? Increased risk of what?
1) pruritic - itchy - skin rash occurs after contacting cercariae (free swimming larval stage looking for intermediate host)
2) Ultimately it is intestinal involvement because tissue is damaged there as part of egg shedding - why there is blood in stool
3) Increased risk of liver failure and mortality and maybe cancer risk (liver or bladder depending on the species)
34
What species of schistosoma affects the bladder?
schistosoma haematobium
35
What are you looking for in blood labs of schsitosoma mansoni?
eosinophilia
36
What type of part of the vascular system to blood flukes invade?
Veins of lower abdominal cavity - mate there and produce fertilized eggs (humans = definitive host)
37
Why are the related Schistosoma species in northern US not a threat?
They cause a rash but humans are not their oat and they cannot complete their life cycles or invade deeper human tissues
38
Schistosomiasis kills how many people? malaria?
300,000
| 1 million
39
Schistosoma life cycle
1) Maricedia hatch from urine/feces
2) enter snail tissue
3) replicate in snail
4) cercariae released by snail and are free-swimming in water
5) penetrate skin of human
6) animals circulate in blood till they migrate to portal blood in liver and mature into adults
7) mature adult worms migrate to the mesenteric venues of the bowel/rectum and lay their eggs that circulate to the liver and shed in stools or go to the venous plexus of the bladder)
(eggs go into stool)
(S. haematobium eggs into bladder urine)
40
Fluke (Trematode) characteristics - low yield
leaf-shaped with oral and ventral suckers
hermaphroditic - schistosoma has two sexes
two intermediate hosts - schistosoma has one host though
MULTIPLE TYPES OF FLUKES!
41
Symptoms of Schistosoma mansoni?
Fever, abdominal pain, bloody stool, increased cancer risk for bladder/ liver; EOSINOPHILIA!
42
Diagnostic methods for Schistoma mansoni?
| Tx?
Assess stool/biopsy for eggs
Tx: praziquantel (impacts calcium regulation of animal)
Advise to avoid affected waters
43
Biopsy of Entamoeba histolytica reveals?
| Serology reveals?
- trophozoites - developmental stage of organism that is detected on H and E stain
- 1:1600 titer for ab
44
Tx for entamoeba histolytica?
Metronidazole (discomfort and ulceration's disappear)
45
Tx for entamoeba histolytica?
Metronidazole (discomfort and ulceration's disappear)
| Kills via Free Radicals
46
How do you get Entamoeba histolytica?
Where is it found (climate)?
Infectious agent?
Who is the central reservoir?
- Ingesting contaminated water/food (contain cysts), contact with contaminated hands, anal sex
- tropics-temperates (warmer climates - africa, asia, south and central america)
- usually cysts, which can survive weeks to months outside a host in the environment (soil/water)
- humans are their ONLY reservoir!
47
What do slides of Entamoeba histolytica look like?
Results in ulceration (inflammation with loss of epithelium - not through entire thickness)
ALSO, have parasites - trophozoites that look like macrophages - but smaller appearance with granular appearance
48
What do slides of Entamoeba histolytica look like? (look at slides for picture!!)
Results in ulceration (inflammation with loss of epithelium - not through entire thickness)
ALSO, have parasites - trophozoites that look like macrophages - but smaller appearance with granular appearance
49
Amebic Colitis for Entamoeba histolytica... How do you diagnose?
Cannot yield diagnosis with microscopic analysis of stool (not enough sensitivity/specificity)
Use ELISA and PCR
Serology can also be used (ELISA plate coated with parasite Ag to detect pt antibodies in blood)
50
Amebas are what class of protozoa?
Locomotion?
Method of reproduction?
Rhizopods
Use Psedopods for locomotion
Method of reproduction = Binary fission
51
Symptoms of Entamoeba histolytica?
Mild/No symptoms
Blood/mucus in stool with abdominal pain (amoebic colitis)
**CYSTS IN STOOL ARE VERY HARDY AND CAN LAST WEEKS!
52
How common are ciliated protozoan parasites? How do they move? Ex.?
RARE!
Move via cilia (do binary fission)
Balantidium coli - cause of diarrhea - hand washing/washing of food prevents
53
How common are flagellated protozoan parasites at causing disease? Ex.? (3)
VERY COMMON!
flagella = locomotion; binary fission
Ex. Giardia lamblia - cause of diarrhea - most common intestinal protozoan in the USA - water borne cysts (campers)
Ex. Trichomonas vaginalis - burning/itchy vanities, yellowish discharge, dysuria and dyspareunia - sexually transmitted
Ex. Trypanosoma cruzi - Chagas disease! (swelling around the eye/infection in the heart)
54
```
Giardia Lamblia - flagellated protozoa - afflicts both humans and animals
Symp?
Disease mechanism?
Diagnostic methods?
Tx?
```
Symp - diarrhea - greasy (wilderness setting = increased risk)
Mechanism: cysts from fecal contamination are swallowed; reproduced in intestine and new cysts are passed in stool
Diag: assess stool; blood serology
Tx - metronidazole
55
```
Trichomonas vaginalis (flagellate class)
Afflicts only humans!!
symp?
mechanism?
diagnostic?
Tx?
```
Men - no symp; Women - burning/itchy/discharge
mechanism - sexual transmission
Diag - swab/pap smear (micrscope)
Tx - Metronidazole
56
```
Trypanosoma cruzi (flagellate class) - Chagas disease
Afflicts only mammals - south america
bodily event?
mechanism?
diagnosis/tx?
```
- envades heart muscle - damages it
- transmitted by insect
- blood smear/serology
- Tx: nifurtimox (ROS, not very effective, avoid if pregnant)
57
Tapeworms are all what type of parasite?
flatworms!
58
Echinococcus granulosis eggs life cycle?
1) ingested with ingestion of dog feceswith embryoniated egg
2) hatch in duodenum
3) develop and invade the liver/lungs and form larval cysts (CYSTICERCOSIS)
59
Echinococcus granulosis definitive host? intermediate hosts (short transition period of development)? accidental hosts?
- dog (ingest cysts through organs)
- sheep, goats, swine, rodents (ingest cysts through feces)
- humans = accidental hosts (cannot transmit the disease) of Echniococcus granulosis
60
Humans are definitive hosts of what tapeworm?
pork and beef (infestations rare due to modern inspection, feeding, and culling)
61
Morphology of Tapeworm (cestode)
head with segmented body (proglottids)
| Hermaphroditic
62
Taenia solium mechanisms?
| Tx?
- when transmitted as cysts in meat, get taeniasis (tapeworm in intestine)
- when transmitted by eggs from human carrier, get cysticerosis (tissue lesions)
- give praziquantel (calcium regulation)
63
High pitched tinkles?
Result of peristaltic attempts to push contents through intestinal obstruction
64
X-Ray/CBC findings with Ascariasis?
```
X-ray = tangled cords in area joining small and large intestine (gas)
CBC = leukocytosis - elevated neutrophils and EOSINOPHILS!
```
65
```
Ascaris Lumbricoides
What type?
Sexes?
Prevalence?
How acquired?
```
Nematode (roundworm)
Separate sexes (4 larval stages then adult)
HIGH PREVELANCE! - billion people
Acquired via fecal-oral transmission of eggs via contaminated food and water (from soil)
Mostly in ASIA!!! and no where in west
66
```
Ascaris Lumbricoides
What type?
Sexes?
Prevalence?
How acquired?
```
Nematode (roundworm)
Separate sexes (4 larval stages then adult)
HIGH PREVELANCE! - billion people
Acquired via fecal-oral transmission of eggs via contaminated food and water (from soil)
Mostly in ASIA!!! and no where in west
67
Ascaris lumbricoides mechanism
Spread by people
Eggs get into intestine, larvae go to lungs, larvae and adults in intestines or other organs, some passed eggs are fully infective, others required time in soil to mature
68
Ascarsis Adults
- morphology?
- travel?
- presentation?
- They are cylindrical
- Larvae migrate via blood through heart, LUNGS, trachea, then swallow, develop in intestine (lay eggs there)
- adult worms may go to any organ (can carry bacteria to liver causing abscesses)
- presentation often vague...GI complaints, have pneumonitis or be asymptomatic (no symptoms unless obstruction occurs); have eosinophilia!!!
69
Ascarsis diagnositcs/tx/control
```
Diag = stool for eggs, worms, radiology to localize
Tx = mebendazole (blocks glucose uptake - diff mechanism than before which was ROS), removal via laproscopy, surgery
Control = improved hygeine, washing of fruits/veggies
```
70
Which intestinal parasite usually has pain?
Giardia (flagellate) - often with steatorrhea (fat with feces - explains greasy stools)
71
Which parasites do NOT cause pain?
intestinal worms-- on occasion see obstruction (e.g. ascaris blocking bile duct flow or child's alimentary canal)
72
Which parasites tend to produce high eosinophilia?
Helminths (esp trematodes and nematodes - flukes and round worms); not usually seen with protozoa
73
Chronic lymphedema? Elephantiasis? Worm?
Chronic lymp = dysfunction results in poor lymphatic drainage
elephantiasis = dysfunction is from parasitic worms
Worm --- filarial round worms (nematodes)
(Wuchereria bancrofti and Brugia malayi)
