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37 Cards in this Set
- Front
- Back
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Which eggs are going to be the easiest to identify?
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Ascarid eggs.
Maybe add the pictures - slide 4/76 |
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What is the unique aspect of ascarid eggs?
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They embryo develops into L3 in the egg and that is what is ingested.
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When might you see unfertilized eggs in the feces?
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When there are no males in the GI.
The signifigance is that the female worms will go looking and could crawl up the throat, or out the nose. |
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Do cool, dry conditions that kill hookworm eggs kill ascarid eggs?
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No, they are very resistant.
Their thick shell and lipid layer around the egg allows this resilience. |
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What is the life cycle of Ascarids?
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slide 9
Usually involve only one host, so have a direct life cycle, but can have a paratenic host. The tracheal migration of ascarids go from intestine, to lungs, to trachea, and back to gut (right?) Pre-patent period ~2 months |
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missed slides up to 13
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go get them
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What are the systemic effects of Ascaris?
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Migrating worms get lost and can cause inflammatory reaction
Migrating worms can cause significant damage to lungs. Cause haemorrhaging where break out of capillaries -Heavy infections: edema clogging of air spaces, Ascaris pneumonitis, secondary bacterial infections Adult worms eat gastro-intestinal contents Usually generalised symptoms of intestinal upset Intestinal blockage worms are robust - may perforate gut, may migrate up bile duct. “Wandering worms” |
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Are Ascarids blood suckers?
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No, they eat what the host eats. Anemia is not a symptom
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What is the most important pathological helminth of swine?
What are the clinical and pathological manifestations? |
Ascaris suum
Clinical & pathological manifestations 1. Milk spot liver – chronic inflammatory changes associated with hypersensitivity to migrating larvae. Livers condemned. 2. Lung lesions = respiratory problems in young pigs (coughing, etc) 3. Adults in intestine. Diarrhea, malnutrition, stunted growth Clinical signs not always present. Even so, growth rate may be reduced by 2-10% and food conversion by 5-13% (experimental infections). Reduction in the digestibility of food has been demonstrated 4. May impair response to vaccines (Mycoplasma hyopneumonia) Overall: respiratory distress, pneumonia, poor growth, emaciation |
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What is this?
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Milk spot liver– chronic inflammatory changes associated with hypersensitivity to migrating larvae. Livers condemned.
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What are the controls and treatments of A. suum?
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Egg removal from animals
Bathe every 2 wks with warm, soapy water to remove eggs (e.g., sticky eggs on hair) Eggs resistant to disinfectants Frequent treatment Treatment: Ivermectin Levamisole 8mg / kg body wt. Fenbendazole Pyrantel tartrate |
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What is the pathology of ascaris in humans?
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Juveniles penetrate lungs
Intestinal: blockage, Humans: 35% cases of acute abdomen deaths in Cape Town Murder weapon: http://en.wikipedia.org/wiki/1970_ascariasis_poisoning_incident |
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What is the life cycle of Parascaris equorum?
What is the signifigance to age in horses? Where do they hang out? What is their pathology? |
Parascaris equorum of equids, a parasite of foals
50 cm long Similar life cycle as Ascaris spp. Older horses immune to infection Intestinal: heavy infections = malnutrition, enlarged abdomen, dull coat, colic, impaction Penetration of bowel = fatal peritonitis Lung and liver damage in sensitized hosts |
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How do you control parascaris?
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1. Adult roundworms, drug treatment: avermectins (ivermectin, eqvalan), benzimadazoles (panacur) and pyrantels (strongid-P).
2. Recommended to worm all horses that are stabled together at the same time Resistance to macrocyclic lactones 3. Pick-up manure from grazing areas, difficult to remove eggs from environment 4. Feed foals off of the ground |
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What is the ascarid of cattle?
What is the life cycle? What kind of transmission occurs along with ingestion? |
Toxocara vitulorum
Direct life cycle Young cattle Ingest eggs Lung migration Mature in small intestine. Egg production 3-5 weeks after infection. Worms do not mature in adult cattle if have had previous exposure (> 4 months old). Transmammary transmission Older animals ingest eggs Larvae migrate through tissues and encyst In pregnant females, reactivate and move to mammary glands Calves ingest larvae and worms mature into adults in their intestine. |
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What is the pathology of Toxocara vitulorum?
What is used in diagnosis? What is the treatment? |
Hosts: May also infect sheep and goats
Pathology; Anorexia, catarrhal enteritis , wasting diarrhea Breath: smells like acetone or butyric acid due to metabolites of worms Diagnosis: fecal examine, breath Treatment: Ivermectin, piperazine, etc. |
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What is the ascarid of raccoons? What other hosts can this worm have?
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Baylisascaris procyonis
Zoonotic Disease Raccoon: Normal host Dogs: Aberrant host, but can support life cycle. Not clinical Human: accidental, dead end hosts. Infections result in severe neurological disease |
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What is the life cycle of Baylisascaris procyonis? Does this worm have tracheal migration? Paratenic hosts?
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No tracheal migration.
Yes paratenic hosts Transmission Direct. Eggs ingested in soil. Paratenic host. Rodent, bird, lagomorph. Larvae wander throughout these hosts and often invade the central nervous system. Debilitation confused for rabies. Makes prey more vulnerable. Zoonotic. Human cases can be severe. Fatal cases reported in humans |
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Does Baylisascaris procyonis cause signs of disease in raccoons? Dogs? Humans?
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Raccoons: (adults) Typically no signs
Dogs: (adults) Typically no signs Humans: (larvae) Larval migrans Larvae wander through tissues as paratenic host Symptoms depend on Tissues invaded Infection dose Severe symptoms when invade brain, spinal cord Nausea Tiredness Liver enlargement Loss of coordination Lack of attention to people and surroundings Loss of muscle control Coma Blindness Take about 1 week to develop symptoms |
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What is the geographic distribution and prevalence of Baylisascaris procyonis?
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Geographic distribution
Where raccoons occur North America (rare in SE U.S.) Japan Germany Prevalence Raccoons: very common (up to 94%) Dogs: about 30 canine cases have been reported If eggs detected—diagnosed correctly? Humans: about 25 cases reported. Thought to be underdiagnosed. Why aren’t there more infections? |
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What is the diagnosis, treatment and way to control Baylisascaris procyonis?
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Diagnosis (dogs and raccoons)
-Finding eggs or adults in feces Treatment (dogs and raccoons) -Most products labeled for Toxocara are probably effective against B. procyonis Control -Dogs should avoid raccoon defecation sites (“latrines”) -Discourage raccoon inhabitation near homes -Eggs are very long lasting in the environment -Pet raccoons |
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What is the ascarid that causes death in pet skunks?
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Baylisascaris columnaris
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What are the ascarids of dogs and cats?
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Cats:
Toxocara cati Toxascaris leonina Dogs: Toxocara canis Toxascaris leonina |
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What is the life cycle of Toxascaris leonina?
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DIRECT LIFE CYCLE
embryonated egg eaten by definitive host enters gut wall for histotrophic phase then re-enters lumen to develop to adult. No extraintestinal migration 2 month prepatent period OR PARATENIC HOST egg eaten by rodent (paratenic host) larvae enter tissue of rodent as 3rd larva rodent eaten by dog, cat or fox histotrophic phase absent or much shorter adults in lumen No extraintestinal migration |
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Is there extraintestinal migration with Toxascaris leonina?
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no
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Is Toxascaris leonina zoonotic?
Are they more or less pathogenic than T. canis and T. cati? How long does it take the eggs to develope? |
Occurs in cooler climates
Rapid development of eggs (ca 1 wk) Less pathogenic than T. canis and T. cati Not zoonotic Eggs are smoother in appearance |
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What species does Toxocara cati infect? Where will we often see the worms? What clinical symptom might it cause?
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Domestic cats and other felids
Often found in vomitis Stunted growth |
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What is the life cycle of Toxocara cati?
Do they undergo extraintestinal migration? |
may have direct life-cycle throughout life of cat
may use rodents as paratenic host may have transmammary transmission (no transplacental) Many do not undergo extraintestinal migration |
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What is the geographic distritibuton of Toxocara cati?
Are they common? Are they zoonotic? How do you diagnose them? |
Geographic distribution
Widespread Prevalence One of the most common feline helminths Zoonotic--Can cause visceral larval migrans, but less common than T. canis Diagnosis Egg in feces |
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What species do the Anisakidae family of helminths infect?
Are they zoonotic? |
Parasites of marine mammals and birds
Zoonosis |
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How are a aquatic parasites zoonotic?
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Acquired by eating fish
Marine: Anisakid nematodes Freshwater: Eustrongylides (Nematoda) Diphylobothrium latum (tapeworm) Heterophyes, Clonorchis, Paragonimus (Digenea) Anisakis simplex - adults in whales, dolphins Pseudoterranova (Phocanema) spp. - pinnepeds (seals) |
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What is the Anisakid life cycle?
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see pic
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How could Anisakis be transmitted zoonotically?
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Source: undercooked or raw seafood products
E.g., ceviche, sashimi, sushi, etc. Fish species: many on the Pacific coast Rockfish (Sebastes spp.) Salmon – 100% wild, absent in farmed Pacific herring – 100% Case Reports: US – 50, Japan – 12,000. |
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What type of host are humans to Anisakis?
How can these infections manifest? |
Dead end host, only L3 or L4
1 “Mouth tickle” – worm migrates to mouth after a few days 2 Penetration of gut: pain, cramps, peritonitis, death (rare) 3 Allergic reactions Fulminated Form: Acute abdomen: ascites, etc. with 2nd bacterial infections Swollen hemorrhagic small intestine with embedded worms No eggs in humans (dead end host) Endoscopy, immunodiagnositcs Gastric: Endoscopic Removal with Biospy Forceps Intestinal: Surgical Resection of Intestine |
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How do you prevent anisakid transmissal zoonotically?
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Prevention:
cook at 60 C for 10 min freeze at 20 C for 60 hrs. candle – inspection of fillets raw fish: pre-freeze |
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What type of host are the crustaceans and fish in the Anisakis life cycle?
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They are intermediate hosts
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What is the life cycle of Toxocara Canis?
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Adult in small intestine of dogs
Eggs released with feces Embryonate in environment Eggs ingested Larvae released in intestine Lung migration Mature in small intestine Produce eggs |
