Parasites of the Nervous System Flashcards
List common parasites of the nervous system (4)
- Taenia multiceps (tapeworm)
- Eyeworms
- Sarcocystis neurona (protozoa)
- Neospora caninum
Taenia multiceps - type of parasite, definitive, intermediate hosts, diseases caused (5)
Taenia multiceps definitive host
Dog (farm dogs), wild canid
Taenia multiceps intermediate hosts
Sheep, goat, cow, pig, horse human
Taenia multiceps metacestode location
Brain, CNS
Taenia multiceps metacestode name
Coenurus cerebralis = GID in sheep (larval stage_
Taenia multiceps cysts in goats
Cysts can mature in subcutaneous and intramuscular sites, metacestode = Coenurus gaigeri
Taenia multiceps life cycle (9)
- Eggs or gravid proglottids in faeces and passed into the environment
- Embryonated eggs and/or gravid proglottids ingested by intermediate host (sheep)
- Oncospheres hatch, penetrate intestinal wall, and circulate to tissue - oncospheres develop into coernuri in tissue of intermediate host (brain + spinal cord (CNS tissue))
- Canids (definitive host) infected by ingesting infected intermediate host
- Scolex attaches to intestine - series of proglottids become more sexually mature so move away from scolex, terminal proglottids are gravid (egg-containing)
- Adults in small intestine - eggs/gravid proglottids pass out in faeces + contaminate faeces + environment
- Embryonated eggs ingested by human host (occasionally infected)
- Oncospheres hatch, penetrate intestinal wall and circulate to tissue
- Coenuri may develop in any organ, being more common in the brain and eyes
Taenia multiceps adult morphology (3)
Taenia multiceps pathogenesis (7)
Taenia multiceps cyst (coenurus) in sheep brain
Clinical signs of acute coenurosis (5)
Clinical signs of chronic coenurosis (7)
Diagnosis of taenia multiceps in intermediate hosts (4)
Diagnosis of taenia multiceps in definitive host
Dogs - presence of tapeworm segments in perianal area or proglottids/eggs in faeces
Taenia multiceps treatment (2)
- Surgery to remove cyst – success rate up to 85% = expensive
- Most farmers slaughter sheep fit for market & euthanase others