L74b: parasitic infections of reproductive system

oocyts

resistant stages for environmental transmission shed in cat feces, only produced by the felid D.H

tachyzoites

rapidly dividing tissue stages found in all vertebrate hosts

bradyzoites

slowly dividing, encysted tissue stages found in all warm-blooded vertebrate hosts

MCQ: Several cows on a farm were aborting and vaginal swabs were taken for cultures. What was the parasite identified?

trichrichomonas

What definition best describes the host in which a parasite undergoes sexual reproduction?

definitive host

What is the definitive host of Toxoplasma gondii?

cats

which parasite is of public health concern?

toxoplasma gondii since zoonotic

who are the intermediate hosts of toxoplasma gondii?

1. rats

2. birds

3. warm-blooded mammals

What stage of toxoplasma gondii will be transferred from mother to fetus?

Tachyzoite

What stage of toxoplasma gondii can be consumed from infected tissue to cause infection?

Bradyzoite

How can toxoplasma gondii be spread from contaminated food and water?

Consumption of sporulated cyst

what is indicative of an active toxoplasma gondii infection?

IgM = active infection; stays elevated for months

what is IgG indicative of in regards to toxoplasma gondii infection?

previous exposure and immunity

what are the most severe signs of toxoplasma gondii in pregnant women?

brain and eyes

what is the number one cause of abortion or stillbirth in sheep in regards to parasites?

toxoplasma gondii

what does toxoplasma gondii cause?

abortion and stillbirth (animals and humans)

what happens after infection of toxoplasma gondii in pregnant animals?

1. TACHYZOITES transmitted through bloodstream to placental cotyledons resulting in cell death, tissue necrosis, and granulomatous inflammation

2. tachyzoites transmitted to fetus

what are the outcomes of toxoplasma gondii in the animal?

1. Mummification

2. resorption

3. abortion

4. weak or stillborn lambs/kids

when can happen in a toxoplasma gondii infection upon host immunosuppression?

Bradyzoites may be reactivated and transform to rapidly dividing tachyzoites leading to severe signs in the immunocompromised adult animal

what can be used in the diagnosis of toxoplasma gondii?

1. PCR

2. histopathology

3. ELISA

4. serology test (IgG and IgM)

5. modified direct agglutination test

6. Sabin-Feldman dye test (GOLD STANDARD)

what stage of toxoplasma gondii is shown?

sporulated and unsporulated oocysts

what stage of toxoplasma gondii is shown?

tachyzoites (ACTIVE STAGE OF INFECTION)

what stage of toxoplasma gondii is shown?

tissue cysts containing bradyzoites

what do we use for treatment of dogs with neurological disease from toxoplasma gondii?

1. Clindamycin & Pyrimethamine

2. supportive care

which animal can be vaccinated for toxoplasma gondii?

• sheep but only in UK and New Zealand

• marketed for breeding ewes

what can we do for control against toxoplasma gondii in cats?

1. do not feed raw meat to cats (freeze meat prior to cooking if want raw)

2. change litter box daily

who are the definitive host for neospora caninum?

1. dogs

2. coyotes

3. gray wolves

who are the intermmediate hosts of neospora caninum?

1. cattle

2. sheep

3. goats

how is neospora caninum transmissed in dogs?

ingestion of infected cattle (placenta and aborted fetuses)

how is neospora caninum transmissed in cattle?

• horizontal (ingestion of sporulated oocysts)

• vertical transmission (transplacental)

what protozoal parasite agent causes ABORTION STORMS in cattle?

neospora caninum

what are clinical signs associated with neospora caninum?

miscarriage and stillbirthweak births with neurological dysfunction of newborns

how do we diagnose neospora caninum in cattle?

histopathology of aborted fetus or placenta

what other tests can we do to diagnose neospora caninum?

1. PCR

2. serological tests (ELISA)

what can we do for the control of neospora caninum?

1. Testing of calves and heifers

2. BiosecurityPrevention of horizontal & vertical transmission

3. Contact between cattle and dogs or canids should be prevented

4. Proper disposal of dead cattle, placentas and aborted fetuses

who are the hosts of TRITRICHOMONAS FOETUS?

bovine

what is the transmission of tritrichomonas foetus?

veneral

where is tritrichomonas foetus located in bulls?

epithelial folds of prepuce and penis

where is tritrichomonas foetus located in cows?

cervix and uterus

what type of life cycle does tritrichomonas foetus have?

direct life cycle

what are the clinical signs of tritrichomonas foetus in cows?

1. endometritis

2. cervicitis

3. vaginitis

4. salpingitis

5. infertility

6. embyronic and early fetal death

when do most cows get infected with tritrichomonas foetus?

at time of breeding mount an immune response and clear the infection after 2 or 3 estrous cycles

what are the clinical signs of at time of tritrichomonas foetus in bulls?

do not show clinical signs are they are clinically normal carriers

what is used for the diagnosis of tritrichomonas foetus?

1. history of decreased calving rates and herd fertility

2. irregular calving distribution

3. organism isolation and ID of vaginal discharge or prepuce samples

4. culture

5. PCR

why is control of tritrichomonas foetus so important?

no effective treatment

what can we do to control tritrichomonas foetus?

1. cull infected bulls older than 4 years old

2. sexual rest for few months of infected cows

3. trichguard vaccine

4. use of AI

sporozoites

occur inside oocysts excreted in the feces of definitive host (sporulation occurs in the environment)

what are the infective stages?

1. sporozoites

2. tachyzoites

3. bradyzoites

What stage of toxoplasma gondii is responsible for chronic infection persistence?

Bradyzoite

What stage of toxoplasma gondii is responsible for acute infection?

Tachyzoite

Which disease are bulls asymptomatic carriers?

Tritrichomonas fetus