Parasites Flashcards

Question

What are the lifecycles of Trichinella spp?

Answer 1

Domestic (pigs due to meat scapes, cannibalism) Sylvatic (Bears-predators/scavengers/cannibalism) Mice also help with this Larvae get eaten and bury into the SI then live in muscle

Answer 2

Animals are symptomatic, only humans show signs of clinical disease

Answer 3

Consumption of raw or poorly cooked meat from bear, walrus, horse , badger, dog, cougar, turtles

Answer 4

The infection fro Trichinella spp. Symptoms appear 5-15 days after Fever, GI upset, headaches, muscle pain, facial swelling, rash Inflammation of heart and muscle and the brain, are serious Acute phase could turn into a chronic phase Very chronic, stays for years (up to 40)

Answer 5

Surveillance Control program inspection of meat plants Prohibition to feed meat and meat by products to swine Consumer Proper cooking of meat, all wild game meat, pork and horse should be cooked to internal 71C Curing, drying, smoking, microwaving does not consistently kill infective larvae Freezing for atleast 3-4 weeks kills some Trichinella species, but not all Wild game meat must be cooked thoroughly

Answer 6

Eggs hatch in saltwater, (free swimming) larvae eaten by crustaceans→ eaten by fish or squid→ nematodes burrow through the intestine for form cysts on outside of organs, sometimes the muscle of beneath the skin Fish eaten my marine mammal or human and the meatotode forms a cyst in the intestine → releases eggs into seawater via host feces

Answer 7

Anyone who eats raw or undercooked fish is potentially at risk (especially homemade sushi) Many cases go undetected

Answer 8

Definitive host: mammals (including humans) | Intermediate host: crustaceans and then small fish/squid (that ate the crustacean)

Answer 9

Symptoms: abdominal pain, nausea, vomiting, diarrhea, obstruction of small intestine Treatment: remove larvae through surgery (if obstruction), likely to die within weeks

Answer 10

``` Cooking seafood to an internal temperature of 63C Freezing fish ( -20 for 7 days or -35 until solid, store at -35 for 15 hours/-20 for 24 hours) ```

Answer 11

Definitive host: wild and domestic cats Intermediate hostL most species of warm-blooded animals (birds, mice, squirrels, rabbits) Cows, chicken, moose, sheep, horse, pig, mice, cariboo, possum

Answer 12

Oocysts are zygotic stage of life cycle, excreted from cat feces Sporulate in 3 days Asexual cycle occurs when consumption fo oocysts results in the infection of the intestine→ tachyzoite in the intestine, multiply until cell ruptures and systemic infection results→ infects new cells in the body- cardiac/CNS Bradyzoites can form in the tissus, if ingested by felid→ sexual cycle occur

Answer 13

Cause acute Toxoplasmosis Invade all nucleated cells and occur in groups Rapid multiplication and lyses cell

Answer 14

Latent toxoplasmosis Tissue cysts contain slow growing trophozoites as bradyzoites Most common in brain, skeletal msucle and cardiac muscle Remain for the life of the host Recrudescence of infection in immunocompromised hosts

Answer 15

Infects all mammals, birds → all tissues → one of the most common human infections thorughout the world High prevalnence in Inuit populations of northnern Canada ( North America (30-35%), Quebec (80%) High in France due to eating undercooked meat

Answer 16

Cats are difinitve hosts Shed oocyst for only 1-2 weeks following infection Sporulate and become infective in 24-48hours Only shed once Oocyst survival Potential to remian viable in the soil fro many years Can be washed into the water system Can sporulate in water and remain infectious for mice for up to 6 months

Answer 17

Acute Tocoplasmosis Caused by invasion of tachyzoites Majority of cases are asymptomatic Mild fever, sore muscles, swollen glands and lymph Cerebral Toxoplasmosis Immunocompromised individuals are at greater risk Bradyzoites can transform into tachyzoites and start propagating Ocular Toxoplasmosis Infection in young children or immunosuppressed individuals commonly results in damage to eyes Ocular symptoms include: strabismus, retinochoroiditis, inactive retinal scarring, panuveitis, uveitis, and neuroretinis Congenitival Toxoplasmosis Pregnant womens fetus are at risk if the mother acquires the first infection during pregnancy May lead to spontaenous abortion, still born, child with severe physical or metal diabilit The baby is only at risk if a woman receives her first exposure to toxoplasmoss while pregnant A woman with no previous exposure should aovid eating and handling raw meat, exposure to cat feces, and gardening ( cat feces common)

Answer 18

Only about 30-40% of women who are infected with Toxoplasma for the first time trasmit the infection to the baby Risk of infecting the fetus is realted to the trimester at whcih acquired Greatest in the third trimester (70%) Early pregnancy is only 15% Severity is inversely related Most severe in first trimester Least severe in last trimester Common defects: blindness, seizures, intellectual disability, hydrocephalus

Answer 19

Humans can becom infected by sevreal routes Eating raw or undercooked meat Food or water contaminated with cat feces Contaminated environmental samples (feca Blood transfusion Transplacentally

Answer 20

``` Wash hands Throuhly cook meat Wash and peel fruits and vegetables Clean littler box daily Feed cat commercial dry food (never raw meat) Cover outdoor sandbozes ```

Answer 21

Oocysts shed in feces of the host, can survive for long periods under coold moist conditions Waterborne route is numerically most important Water, food, travel , communities, HIV → how it is tranmitted, more at risk

Answer 22

In HIV individuals Prevalence in HIV with diarrhea is 3-16% C. parvum is primarily reponsible for watery diarrhea tha last for >30 days Mortality of AIDS pateints is 42% In children Mayn children die of diarrhea Parasites are leading agents of chronic or persistent diarrhea worsened by specific risk factors such as malnutrition or immune deficiency Healthy Individuals Self-limiting and usually last for 1-2 weeks, diarrhea, abdominal pain, weight loss, nausea, vomting, fever

Answer 23

Human-human day cares, hospitals, households Animal-human Farm visits of school children, petting zoo, turkey farms, pet animals WAter Drinking water, recreational water, swimming pools Food Fresh produce, unpasterurized apple cider

Answer 24

Resistant to chlorine and disinfectants Wash raw fruit and vegetables Avoid swallowing recreational water Avoid drinking untreated water or treat water before drinking Avoid unpasteurized milk or fruit juices Wash your hands after contact with farm animals Use caution when travelling to countries where water supply might be unsafe

Answer 25

Cyst: infective stage Cysts can survive inwater at 4C for 3 months 10 cysts are sufficient to infect humans

Answer 26

Worldwide Giardisis is a major diarrheal disease foudn throughout the world Most common identified parasite in the US Most common protozoal intestinal parasite isolated worldwide Farm Prevalnce- cows can harbour asymptomatically Dairy Beef

Answer 27

Some people can carry giardia parasite without experiencing any symptoms Symptoms start 1-2 weeks after exposure Common symptoms: fatigues, nausea, diarrhea or GREASY stools, loss of appetite,vomitng, blatoing and abdominal carmaps, weight loss, excessive gas, headaches, abdonmial pain Infectiosn last 6-8 weeks, but problems sucha s lactose intolerance persist post infection

Answer 28

``` Human to human Animal to human Resevoir: cats, dogs, cattles, sheep, pigs, rodents, beavers, bears Water Drinking water, recreational water Food Fresh produce (herbs, leafy greens) ```

Answer 29

It is chlorine resistant Avoid drinking intreated water or treat water beofre drinking (boil for 1 minute) Wash hands after handling soil or feces Use caution when travelling to countries where water supply might be unsafe Avoid swallowing recreational water Wash raw fruits and vegetables before eating

Answer 30

Giardia, Cryptosporidium

Answer 31

Contaminated water for irrigation, mixing pesticides, washing and processing Application of manure or sweage to crop lands Direct access to crops by wildlife and livestock Contaminated equipment Poor hygiene of infected food handlers/consumers Cats contaminate crops and livestock feed and water

Answer 32

Use treated water for irrigation, washing hands/equipment Monitor heatlh and hygiene of farm workers (education) Improved on-farm sanitation Use of properly composted manure Restricted access by livestock and other animals Environmetnal resistance of cysts/oocysts

Answer 33

Use of treated water for washing/processing produce and equipment Monitoring health and hygiene of farm workers (education) Chemical and physical disinfectants

Answer 34

Good personal hygiene (handwashing washing /rinsing of produce Cooking and freezing