TOXOPLASMOSIS & NEOSPOROSIS Flashcards
(100 cards)
1
Q
causative agent of Toxoplasmosis
A
Toxoplasma gondii
2
Q
What kind of parasite is the Toxoplasma gondii?
A
obligate intracellular coccidian parasite
3
Q
Infects virtually all species of warm-blooded animals including people.
A
Toxoplasmosis
4
Q
intermediate hosts of Toxoplasma gondii that harbor tissue cysts
A
All nonfeline hosts
5
Q
Definitive hosts of Toxoplasma gondii that excrete oocysts.
A
Domestic cats and other Felidae
6
Q
Three infectious stages of T. gondii
A
- Sporozoites in oocysts
- Tachyzoites or Trophozoites
- Bradyzoites
7
Q
oocysts of T. gondii are excreted in?
A
feces
8
Q
actively multiplying stage of T. gondii
A
Tachyzoites or Trophozoites
9
Q
slowly multiplying stage of T. gondii enclosed in tissue cysts and found in tissues
A
Bradyzoites
10
Q
Three Major Modes of Transmission of T. gondii
A
- Congenital infection/Transplacental transmission
- Ingestion of infected tissues
- Ingestion of oocyst contaminated food or water
11
Q
Other Minor Modes of Transmission of T. gondii
A
- Lactational
- Transfusion of body fluids
- Transplantation of tissues or organs
12
Q
have also been implicated as carriers of the infective stages of T. gondii from cat feces to food
A
Flies and cockroaches
13
Q
They would serve as potential mechanical vectors for transmission to people as they shed ingested sporulated oocysts in their stool
A
Dogs ingesting cat litter
14
Q
In toxoplasmosis, parasitemia during pregnancy can cause ________ followed by spread of tachyzoites to the fetus.
A
placentitis
15
Q
Tissue cysts of T. gondii are formed in the following organs (ENUMERATE) and probably persist for the life of the host.
A
central nervous system (CNS), muscles, and visceral organs
16
Q
In toxoplasmosis, postnatally acquired infections are generally asymptomatic and self-limiting, usually persisting how many days/weeks/months?
A
1 to 12 weeks
17
Q
In toxoplasmosis, ________ acquired infections are generally asymptomatic and self-limiting, usually persisting 1 to 12 weeks.
A
Postnatally
18
Q
In toxoplasmosis, is reactivation of chronic latent (encysted) infection possible?
A
Yes
19
Q
How long oocysts of T. gondii could stay infective in the environment?
A
one year
20
Q
oocysts of T. gondii are remarkably resistant to the disinfectants, freezing and drying, but are killed by heating to what temperature and time?
A
70˚C for 10 minutes
21
Q
oocysts of T. gondii are remarkably resistant to?
A
disinfectants, freezing and drying
22
Q
In cases of toxoplasmosis, parasites (tachyzoite) multiply rapidly in the tissues during what stage?
A
acute stage
23
Q
In cases of toxoplasmosis, this stage multiply rapidly in the tissues during acute stage.
A
tachyzoite
24
Q
In the case of toxoplasmosis, wha stage follows in 1-2 weeks where parasites are rarely seen in the blood
A
Subacute stage
25
In the case of toxoplasmosis, Subacute stage follows how long? where parasites are rarely seen in the blood
1-2 weeks
26
Cysts containing this infective stage of T. gondii develop which persist for months or years (chronic stage which is usually asymptomatic)
bradyzoites
27
Cysts containing bradyzoites T. gondii develop which persist for months or years (________ stage which is usually asymptomatic)
chronic stage
28
This immunity develops after 7-10 days where lesions of toxoplasmosis subside.
Cellular Immunity
29
Cellular Immunity of Toxoplasmosis develops after how many days where lesions subside?
7-10 days
30
are common sites of initial replication and chronic persistence of Toxoplasmosis infection
brain, liver, lungs, skeletal muscle, and eyes
31
The clinical outcome of Toxoplasmosis is determined by the extent of injury to these organs, especially vital organs such as the?
heart, lung, liver, and adrenal glands
32
cell types that appear susceptible to T. gondii
All cell types
33
is caused by the intracellular growth of Toxoplasma.
Cell necrosis
34
In infections acquired after the ingestion of tissue cysts or oocysts of T. gondii, initial clinical signs are caused by the?
✓ necrosis of intestine
✓ associated lymphoid organs caused by tachyzoites
35
Postnatally acquired toxoplasmosis is generally less serious than is ______ acquired infection.
prenatally
36
may also aggravate T. gondii infection
Stress
37
Historically, the prevalence of canine toxoplasmosis has decreased with the routine use of these vaccines.
canine distemper vaccines
38
Clinical signs of this disease may be localized in respiratory, neuromuscular, or gastrointestinal (GI) systems, or they may be caused by generalized infection.
Toxoplasmosis
39
Clinical signs of Toxoplasmosis may be localized in the following system, or they may be caused by generalized infection.
respiratory, neuromuscular, or gastrointestinal (GI) systems
40
The neurologic form of toxoplasmosis may last for several weeks without involvement of other systems, whereas severe disease involving the ____ and _____ may kill dogs within a week.
lungs and liver
41
Generalized toxoplasmosis is seen mostly in dogs at what age and is characterized by?
younger than 1 year
fever, tonsillitis, dyspnea, diarrhea, and vomiting
42
Icterus usually results from extensive hepatic necrosis in this disease
Toxoplasmosis
43
Dogs with myositis may initially show abnormal gait, muscle wasting, or stiffness in this disease
Toxoplasmosis
44
What disease may result in paraparesis and tetraparesis that may rapidly progress to lower motor neuron paralysis?
Toxoplasmosis
45
Canine toxoplasmosis is clinically similar to what infection, which was previously confused with toxoplasmosis.
Neospora caninum infection
46
Canine CNS toxoplasmosis may occur concurrently or be predisposed by?
canine distemper virus infection
47
Nonregenerative anemia, neutrophilic leukocytosis, lymphocytosis, monocytosis, and eosinophilia are most commonly observed in this type of infection
Toxoplasmosis
48
Biochemical abnormalities during the acute phase of Toxoplasmosis include _______ and ________.
Dogs generally have increased serum ALT and alkaline phosphatase (ALP) activities with hepatic necrosis.
hypoproteinemia and hypoalbuminemia
49
This serological test is highly sensitive and specific for human toxoplasmosis. Moreover, the test is too technical to perform in diagnostic laboratories, and it uses live T. gondii.
Sabin Feldman dye test
50
Test that uses live T. gondii.
Sabin Feldman dye test
51
is comparable to the dye test but does not require live Toxoplasma gondii antigen
Indirect fluorescent antibody technique (IFAT)
52
is the drug of choice for treating clinical toxoplasmosis in dogs and cats because of its good intestinal absorption
Clindamycin
53
Combination of these drugs is synergistic in the therapy of systemic toxoplasmosis.
pyrimethamine and rapid acting sulfonamides
54
intermediate hosts or mechanical vectors of Toxoplasma gondii
cockroaches, earthworms, rodents
55
internal temperature of meat to kill Toxoplasma gondii infective stages
≥ 67° C or 152.6°F
56
is an effective method for killing Toxoplasma gondii
Freezing of meat in home freezers (−12° C) for at least 24 hours
57
at doses of 5 centigray this process has been effective in killing Toxoplasma gondii
Gamma-ray irradiation
58
An oral vaccine containing live bradyzoites of a mutant strain (T 263) was reported for?
reducing oocyst shedding by cats
59
This vacine was reported for reducing oocyst shedding by cats. The vaccine strain itself does not produce oocyst shedding.
oral vaccine containing live bradyzoites of a mutant strain (T 263)
60
is an important neuromuscular disease of domestic dogs and wild canids worldwide.
Neosporosis
61
neosporosis was first described as a distinct disease in what year?
1984
62
In what year, the causative organism, Neospora caninum, was identified.
1988
63
is the most common cause of abortion in cattle and is a cause of infertility and neonatal mortality.
N. caninum infection
64
N. caninum infection is the most common cause of _______& in cattle and is a cause of ______ and ______.
abortion
infertility and neonatal mortality
65
is an obligate intracellular coccidian protozoal parasite of the phylum Apicomplexa
Neospora caninum
66
Neospora caninum is an obligate intracellular coccidian protozoal parasite of what phylum?
Apicomplexa
67
The stages of Neospora caninum that resemble those of T. gondii under light microscope.
tachyzoites and tissue cysts (bradyzoites)
68
is the definitive host and sheds oocysts following ingestion N. caninum–infected tissues
domestic dog or the coyote (Canis latrans)
69
Shedding in some instances of N. caninum oocyst has been documented up to ___ months by both of these methods (ENUMERATE 2)
4 months
visual inspection and PCR methods
70
are shed later after ingesting tissue cysts
Unsporulated oocysts
71
Sporulation of N. caninum oocyst occurs after how many hours outside the body?
24 to 72 hours
72
Sporulated oocysts contain how many sporocysts and sporozoites
2 Sporocysts, each with 4 Sporozoites
73
In naturally infected dogs with N.caninum, the predominant route of transmission is considered to be ________ and a clinical sign is often an exacerbation of congenitally acquired infection.
transplacental
74
The disease is best known for causing loss of pregnancy in cows, especially on farms with dogs.
Neosporosis
75
Neosporosis is best known for causing what?
loss of pregnancy in cows
76
Dogs with Neosporosis typically do not show signs of infections. Signs are most commonly observed in puppies.
77
Purebred dog that have been noticeably prevalent in published case reports with Neosporosis.
German shorthaired pointers, Labrador retrievers, golden retrievers, boxers, basset hounds, and greyhounds
78
Patency of N. caninum oocyst
3 weeks
79
When a dog ingests N. caninum oocysts (or tissue cysts), sporozoites release from sporulated oocysts (or bradyzoites excyst from tissue cysts) within the ______. These stages then transform into tachyzoites within the ________. Tachyzoites multiply asexually and disseminate.
duodenum
intestinal epithelium
80
In cases of Neosporosis, neuronal cell destruction within _____ and _____ produces neuromuscular disease.
cranial and spinal nerves
81
The host's immune response to N caninum can lead to differentiation of tachyzoites into bradyzoites (with tissue cyst formation). Cysts are found primarily in what tissues?
muscles and CNS tissues
82
Experimental studies suggest that N. caninum can cause the following conditions in puppies.
early fetal death, mummification, resorption, and birth of weak pups
83
is a major feature of the Neosporosis in cattle
abortion
84
In Neosporosis, most severe (disseminated) and frequent infections have been in young (under 6 months) dogs that showed this condition.
ascending paralysis of the limbs
85
In the youngest pups, signs associated with Neosporosis are often noticed beginning at what age?
3 to 9 weeks of age
86
Features that distinguish neosporosis from other forms of paralysis are
gradual muscle atrophy and stiffness, usually as an ascending paralysis
87
are more severely affected in cases of ascending paralysis associated with Neosporosis
pelvic limbs are more severely affected than are the thoracic limbs
88
In some pups with Neosporosis, this conditions may develop.
joint deformation and genu recurvatum
89
Cervical weakness, dysphagia, megaesophagus, and ultimately death occur.
Dogs do not develop severe intracranial manifestations and maintain alert attitudes.
They can survive for months with hand feeding and care but remain paralyzed with associated complications.
What disease?
Neosporosis
90
Dogs Older Than 6 Months with this disease often have signs of multifocal CNS involvement with or without polymyositis; less common manifestations result from myocarditis, dermatitis, pneumonia, or multifocal dissemination.
Neosporosis
91
has been most common in dogs that become immunosuppressed from concurrent illnesses or drug therapy.
Cutaneous neosporosis
92
Signs of a multifocal CNS problem (eg, paralysis, tremors, difficulty swallowing) or myositis (eg, muscle weakness, swelling, pain, and atrophy) are the common clinical signs of what disease in adults?
neosporosis
93
Drugs that can be used alone or in combination have been administered to treat canine neosporosis.
Clindamycin, sulfadiazine, and pyrimethamine
94
Neosporosis:
Dermatitis and myositis have responded to therapy with this drug.
clindamycin
95
is effective in suppressing the replication and dissemination of tachyzoites but does not appear to be effective against encysted bradyzoites.
Clindamycin
96
Clindamycin is effective in suppressing the replication and dissemination of ______ but does not appear to be effective against _____.
tachyzoites
encysted bradyzoites
97
Neosporosis with neurologic involvement, these drugs should be used because of better penetration of the CNS.
trimethoprim-sulfonamide or pyrimethamine and sulfonamide
98
To avoid Neosporosis, dogs should not be fed uncooked meat, especially tjis type of meat.
beef
99
The sexual cycle of Toxoplasma gondii is restricted to cats, the only mammals to lack what type of enzyme activity?
lack delta-6-desaturase
100
The sexual cycle of Toxoplasma gondii is restricted to cats, the only mammals to lack delta-6-desaturase activity, with consequent high levels of __________. This allows Toxoplasma sexual development in mice, potentially opening up alternative model hosts.
linoleic acid
