Parisitology Week 1

Front 1

Define Parasite

Back 1

Organism of the animal kingdom, that lives in or on another organism

Front 2

What is is an ECTOparasite?

Back 2

An external parasite that lives on the outside of another animal such as fleas, ticks, mites, flies

Front 3

What is an ENDOparasite?

Back 3

An internal parasite that lives in tissues or body cavities of an animal.

Front 4

Most endoparasites live within

Back 4

the GI tract---> mouth, esophagus, small and large intestines

Front 5

Most endoparasites that live in the intestines live in which intestine and this results in____

Back 5

Small intestine, (mysentary is connected to SI)

results in loss of nutrients

Front 6

Esophogeal parasites do what?

Back 6

Burrow into tissue lining the esophagus

Front 7

Ruminants endoparasites tend to make their home where?

Back 7

Stomach

Front 8

Endoparasites that invade the liver have eggs that pass via __________ to the intestines and then exit host via feces

Back 8

Common bile duct

Front 9

An example of pulmonary parasites is

Back 9

lung worms

Front 10

an example of circulatory system parasites is

Back 10

heartworms

Front 11

An example of urinary system worms is

Back 11

Kidney and bladder worms

Front 12

A stationary parasite is one that _____________________-

Back 12

Attaches somewhere and STAYS there (i.e. Demodex- burrowing mite

Front 13

A periodic parasite is one that ______

Back 13

is on and off the host during part of its life cycle (ie-fleas)

Front 14

Permanent parasites __________

-All internal parasites are permanent
-Some external parasites are permanent
-Some permanent parasites are stationary parasites, but not all

Back 14

stay on host ALL the time

Front 15

An Obligate parasite is one that

Back 15

MUST live as a parasite-cannot live on its own
- much more common type
-Always have a final host ( not true for facultative parasites)
ie-lice are obligate and permanent but not stationary

Front 16

A facultative parasite is one that

Back 16

involves 2 generations of parasites
1. A free living generation that can live at the expense of another organism OR can live on its own (ie-Stronyloides)
2. An obligate generation that must live at the expense of another organism

Front 17

What does the term host refer to?

Back 17

The animal a parasite lives IN or ON at any given time. the Host "harbors" the parasite at some stage of its life cycle

Front 18

A final or definitive hosts is one that____

Back 18

Harbors the adult stage.

**EVERY parasite must have a final/definitive host***

Front 19

An intermediate host is one that_____

Back 19

harbors a larval stage and is necessary to the parasite in completion of its life cycle

-not all parasites have an intermediate host but some may have 2

Front 20

A transport or paratenic host is an accidental host that

Back 20

is unnecessary but convenient host that harbors larval stage of a parasite

-no development occurs in this type of stage

Front 21

All parasites are Host specific but there are two types, one is Host Specific Singular (HSS) and this refers to:

Back 21

Only one animal will harbor the adult stage

(ie-Toxocara canis-dogs only)

Front 22

All parasites are Host specific but there are two types, one is Host specific plural (HSP) and this refers to:

Back 22

More than one animal can harbor adult stage

(ie-cow and sheep)

Front 23

What is a parasitic life cycle?

Back 23

The reproduction and maturation series of a parasite and its development through stages

Front 24

A direct life cycle (DLC) is one that means the parasite __________

Back 24

does not need the use of an intermediate host but can use a paratenic host

Front 25

An indirect life cycle (IDC) is one in which the parasite __________

Back 25

MUST make use of an intermediate host

Front 26

What are the three stages of the typical life cycle of a parasite or protozoa?

Back 26

1. Egg, ova or cyst
--protozoans produce cysts
2. Larva--all have at least one stage
3. Adult--stage that causes infestation

Front 27

In terms of parasites, an infestation refers to

Back 27

Establishment of a parasite within or upon a host and this occurs at the adult stage of the life cycle of the parasite

Front 28

Infection is something caused by bacteria and viruses and is not the same as infestation. Parasites do have an Infective stage however and this refers to:

Back 28

Stage the parasite can infest the host

Front 29

Routes of infestation refers to:

Back 29

how the parasite enters the host. this is the point where the parasite has reached the "infective stage" and can be the egg/ova, cyst or larva

Front 30

What are some common routes of infestation?

Back 30

-Direct---most common
-Ingestion of paratenic host
-In utero-transplacental
-ingestion of intermediate host
-skin penetration (hookworms)
-transmammary-lactogenic)

Front 31

The prepatent period (PPP) refers to:

Back 31

Amount of time which elapses, from the time a final host is infested, until the parasite can be demonstrated through the detection eggs/ova, cysts or larvae.
-this is the time it takes parasite to become reproductively mature

Front 32

The first growth stage of a Parasite is the __________-

Back 32

Egg or ova

-Diagnosis of these via examination of feces, blood or urine

SIZE and APPEARANCE are critical in diagnosis

Front 33

A cyst is a:

Back 33

protozoan ova or egg

Front 34

What are the major differences between eggs/ova and cysts?

Back 34

-Eggs are usually larger than cysts
-Eggs have a thicker cell wall
-Cysts tend to be filled with fluid therefore are more fragile
-Ova are filled with cytoplasm, nucleus etc (hardier

Front 35

What are the 4 shapes of eggs or cysts?

Back 35

Majority are round or oval

One type found in cows in triangular and one with D shaped ends is found in horses

Front 36

What a larva?

Back 36

a growth stage following the egg or ova stage. A microscopic "baby worm"
Larval stage one is L1 although some may have as many as 5 larval stages (L1 to L5)

Front 37

What is an operculum?

Back 37

An indentation or protrusion on one or both ends of oval shaped eggs/ova
-can be single with an in or out
-Doubles always protrude out

Front 38

Public health significance (PHS) refers to:

Back 38

Damage a parasite has the potential to do to the public

Front 39

Pathology and pathogenicity refer to __

Back 39

the damage a parasite is capable of producing to its host

Front 40

Morphology is the study of

Back 40

shape

Front 41

A hermaphroditic parasite is one that

Back 41

contain both sets of nonfunctional sex organs that become functional once they reach the final host

Front 42

A monecious parasite is one that

Back 42

Contains both sets of sex organs and BOTH are functional

Front 43

A dioecious parasite is one that

Back 43

Has one set of either male or female sex organs that are functional

Front 44

Oviparous reproduction refers to:

Back 44

Production of ova within the parasite, which then passes out of the parasite and into the host, then out of the host as ova
**MOST COMMON**

Front 45

Ovoviviparous reproduction refers to:

Back 45

Production of ova within the parasite , that pass into the host as ova, THEN hatch into larvae and pass out of the host as LARVAE

Front 46

Viviparous reproduction refers to

Back 46

Production of an ova within the parasite which hatch into larvae within the parasite as well and then pass into and out of host as larvae

Front 47

Parasitiasis refers to

Back 47

the fact that there are parasites present in/on a host and although potentially pathogenic, host shows no outward signs

Front 48

Parasitosis refers to

Back 48

Parasite is present in or on host and animal exhibits outward signs and harm

Front 49

What are some of the ways a parasite/protozoan can cause its host harm?

Back 49

1. absorbing food meant for host (malnutrition, malabsorption)
2. Sucking blood or lymph
3. Feeding on tissues of host
4. Causing mechanical obstruction or pressure
5. Causing growth of nodules or tumors
6. Perforating tissues or vessels
7. Causing wounds through which infestation and possibly infection can occur
8. Destruction of tissue
9. Irritation of tissues
10. Transmitting some infestious disease such as malaria, viruses, blood protozoa
11. secreting toxins or otherwise harmful substances such as digestive or anticoagulatory enzymes

Front 50

A Qualitative test is one of the more common tests for parasites and it tests simple for ______________

Back 50

If the animal does or does not have the parasite at that given time

Front 51

The less common type of the 2 general parasite tests is the Quantitative test and it refers to :

Back 51

Approximate degree of infestation and is never done unless there is a positive qualitative test

Front 52

Types of samples used for qualitative tests most often are:

Back 52

fecal
blood
urine

Front 53

If nothing is seen on a test, repeat with another sample on another day UNLESS significant signs are being shown> based on Hx, parasite may still be

Back 53

In PPP and it will be best to do a follow-up test a week later

Front 54

What are the 3 types of qualitative tests done most often on a fecal sample?

Back 54

1. Gross or visual
2. Direct smear
3. Concentration or flotation technique

Front 55

What are 7 of the 14 factors that can cause variations in results?

Back 55

1. Ova producing potential varies greatly among parasites
2. With heavy infestations, females produce fewer eggs
3. Sex ratio may not be the same, though both sexes cause harm
4. Could be a large # of immature, non-egg producing worms present (parasite in the PPP)
5. Diet of host greatly affects # of eggs produced (alfalfa enhances egg production in ruminents)
6.egg output is not a constant process and number of eggs found will vary hour to hour and day to day
7. Fecal consistency affects # of eggs present

Front 56

What are the other 7 of the 14 factors that can cause variations in results?

Back 56

8. fecal output varies among animals due to species, age and size
9. Immune response may in some cases inhibit/stop egg production, may speed up production in some cases
10. Different diagnostic techniques used to determine number of eggs will produce varying results
11. Technician error
12. Luck--just happen to have part of sample with parasite in it
13. Inadequate sample size
14. Sample is too old

Front 57

Sodium nitrate is not as efficient in floating eggs as:

Back 57

Zinc Sulfate

Front 58

Concentration techniques will yield __________ eggs per gram of feces compared to simple flotation techniques.

Back 58

MORE

Front 59

Refrigeration of fecal sample does what?

Back 59

-slow down cyst rupture and larvation of the eggs

Front 60

Lab test results are reported in both the ____________ and ____________

Back 60

Lab log and patients file

Front 61

With a fecal exam, can often see ________ with the naked eye.

Back 61

adults

Front 62

Tapeworm segments are usually viewed with _____ on a microscope, although they can be seen with the naked eye.

Back 62

4x

Front 63

To view eggs, cysts and larva, use ______ magnification and _____ to ID

Back 63

10x
40x

Front 64

With Giardia, the smallest cysts we come across, you use ____ to locate and ID

Back 64

40x

Front 65

Scanning for eggs/ova & cysts is done on __________magnification and no staining is done on these slides

Back 65

10x

Front 66

The exception to the scan on 10x rule is when you are scanning for Giardia and its 2 forms. What are they?

Back 66

Cysts
trophazoites (kite with multiple flagella)

Front 67

When scanning, it is best to use two hands, one on the ______and the other on ____________ to continuously fine focus back and forth.

Back 67

fine focus knob
stage movement knob

Front 68

When something is found while scanning left to right, top to bottom while scanning in an overlapping manner, you should ___________

Back 68

Move to 40x, write down what you see, then go back to scanning on 10x

Front 69

When you find something, you may or may not be able to give its Genus of the parasite. If you do not find something, you ___________report out__________ because____________

Back 69

NEVER
negative
parasite could be in another part of the sample or in PPP

Front 70

NSATT and NoPSATT are used to report nothing found and they stand for:

Back 70

Nothing seen at this time

No ova/parasites seen at this time

Front 71

What are the 3 tests ALWAYS done on a fecal?

Back 71

1. Gross or visual- (NO microscope)

2. Direct smear

3. Fecal concentration/flotation

Front 72

What are some reason for doing a direct exam on a fecal sample?

Back 72

1. Tapeworms are often Dx by segments in sample
2. Sometimes adult worms are passed (roundworms)
3.Odor of feces can give hints as to type of parasite (Giardia) as well as consistency. (diarrhea can be viral/bacteriological in origin, not just parasites)
4. Excessive mucous can be indicative of Whipworms but can be
associated with colitis and not have parasites as a cause.

Front 73

What are the advantages of doing a Direct Smear, the 2nd test that should ALWAYS be done on a fecal sample?

Back 73

Fast-quick prep time

Cheap- just need slide, cover slip, applicator stick and PSS

Front 74

The disadvantages of Direct Smear fecal test are?

Back 74

1. Small amount of feces used- (can miss something)
2. May need to contend with a greater amount of fecal debris while scanning

Front 75

What are the basic steps for doing a fecal Direct Smear?

Back 75

1. Obtain a tiny fleck of sample
2. Use 2-3 gtts PSS
3. Mix with app. stick gently ( do NOT lay on counter)
4. Take cover slip, hold by edges at 45 degree angle, gently skim top of sample across sample then drop cover slip down
5.Place slide on stage on 10x, condenser down

Front 76

What are the reasons a Direct Fecal Smear is done?

Back 76

1. Only test where you are able to see larvae
2. Can see the 2 forms of Giardia
-Cysts are more fragile and more likely to rupture
-Trophozoites even more fragile and are ID 'd by their kite shape and 8 flagella

Front 77

For the 3 test that is always done on a fecal sample, the Concentration or Flotation technique, the specific gravity of the flotation solution is_____?

Back 77

1.180-1.200

Front 78

Using the flotation solution with a particular specific gravity of 1.180 to 1.200 leads to the heavier material ________ and the lighter Ova to _____.

Back 78

sinking

rising to the top

Front 79

In a flotation/concentration test, larvae are about the same weight as _______ and will therefore ______

Back 79

debris, sink

Front 80

The cover slip touches the meniscus at the top of the test where it sits for ________ to collect Ova that may rise to the top of the solution.

Back 80

10 minutes

Front 81

Solutions for this floatation tests are too potent for ___________ and will therefore cause them to rupture and the sensitivity of Giardia cysts will make fewer of them seen with this technique

Back 81

trophozoites

Front 82

Sample size is about the size of a pea, bigger amount than used on Direct smear test, so there is a ___________

Back 82

greater potential for seeing something

Front 83

What are the 3 types of flotation media (solutions)?
** technically, these are drugs because they aid in the Dx of something)

Back 83

1. Sodium Nitrate (NaNO3) Brand names Fecasol, Flomed, Ovassay

2. Zinc Sulfate (ZnSO4) Some studies show this to be best but is more expensive

3. Sheather's Sugar solution- has a specific gravity of 1.270 and can float any ova

Front 84

Advantages of flotation/concentration techniques are:

Back 84

1. greater potential for recovering eggs/cysts
2. larger sample size leads to #1
3. Less fecal debris to contend with because it sinks to the bottom

Front 85

What are the 5 techniques used for flotation/concentration tests?

Back 85

1. Willis
2.Fecalyzer
3. Ovassay
4. Ova-tector
5. Centrifugation

Front 86

The Willis Simple Flotation technique is the first one to come out and 2 of its advantages are:

Back 86

Cheap, vials can be cleaned and reused

Easy to do

Front 87

What are some advantages of the Fecalyzer (green), the commercial version of the Willis test?

Back 87

-Disposable
-Less debris due to secondary filter
-Easy for client to use to collect sample from their pet

Front 88

What is a disadvantage of the Fecalyzer test?

Back 88

Cost

Front 89

The Ovassay (white) is a test that is very similar to the Fecalyzer but with some distinct disadvantages. What are they?

Back 89

It is a generic version that is more cheaply made and has a poor seal that leaks

Front 90

What are some disadvantages of the Ova-tector?

Back 90

This less often used test is harder to use and has many pieces.

Front 91

Of the 5 flotation tests, the most effective is the Centrifugation technique. Its advantages are:

Back 91

1. More efficiently recovers parasite eggs parasite eggs and cysts than any other method.
2. Requires less time
3. Less egg/cyst distortion
4. Even less fecal debris than the other flotation/concentration techniques

Front 92

With Centrifugation, a Swing-head centrifuge is used to allow gravity and suction to hold the cover slip on. Gravity forces ______________

Back 92

lighter stuff to top and heavier stuff to the bottom to a greater degree than other flotation techniques.

Front 93

What are a few items to remember when setting up the Centrifuge fecal test?

Back 93

1. Tube holder has to be slightly shorter than tubes used ( needs to 5cc size)
2. Don't re-use tubes
3. Arms are numbered, so write down # on reporting lab sheet to keep sample and patient matched
4. Must be balances, so put tube with water on opposite side.
5. Spin for 3 minutes at 1200 to 1500 rpm

Front 94

When is Lugol's iodine used?

Back 94

To attempt to view protozoa cysts such as Coccidia and giardia.

Front 95

Lugol's Iodine is used on direct smears and with concentration techniques. If cysts are present and can be seen, they will look like:

Back 95

A cell with double walls that look like 2 thin black lines which have a greenish color in between them. To double check, turn fine focus back and area cell wall will look like on thick black line and then fine focus the other way to see if greenish color returns between the double walls.

Front 96

When using Lugol's Iodine on a direct smear, you need _____ of iodine to see if trophozoites are present.

Back 96

1 gtt

Front 97

When using Lugol's Iodine with a concentration technique, never drop it directly on feces.Fill container _______, then add _______ of iodine.

Back 97

2/3rds full

2 gtts

Front 98

A forth type of fecal test that may be done in addition to the Gross exam, direct exam and Flotation test, is the Fecal Cytology test, aka Fecal smear, and the purpose of this test is to view:

Back 98

Clostridium -looks like safety pins

Campylobacter -a spirochete/seagull appearance

Front 99

What is the basic procedure for doing a Fecal Cytology/smear?

Back 99

1. Obtain a fleck of of feces and roll it onto a slide and allow to dry.
2. May heat fix slide
3. Then stain the slide with Diff quick and examine on 100x.

Front 100

What is the procedure for using the 3 solutions used for doing a Diff Quick stain?

Back 100

#1 is the Fixative which is blue/green color and slide is dipped 5 times for 1 second.
#2 is The Eosinophilic and slide is dipped 5 times for 1 second.
#3 is Basophilic which is bluish/purplish and slide is dipped 7-10 times for 1 second.
-Rinse with cool water and allow to dry

Front 101

On a fecal cytology, it is normal to see less than ___________

Back 101

5/hpf as this is usually NF

Front 102

Always report out the ______________

Back 102

number per HPF after checking a minimum of 10 fields---average this

Front 103

Some clinics will require you to set up 3 slides when doing a routine fecal exam. What tests make up the fecal 3?

Back 103

Direct, Float and cytology

Front 104

What are the 3 main purpose of veterinary Cytology?

Back 104

Locate

ID

Treat