importance of zoonotic parasites SDL Flashcards
what is toxocariasis
infection caused by larvae of toxocara spp
explain the lifecycle of toxocara and how zoonotic transmission occurs
Toxocariasis is caused by worms found in some dog, cat and fox poo.
Animals with these worms in their digestive system can pass out worm eggs in their poo. You can become infected if poo, soil or sand containing these eggs gets in your mouth.
Toxocariasis is not caught from fresh poo. It’s usually caught from soil or sand that has contained worm eggs for a few weeks or months.
Toxocariasis cannot be spread between people.
is toxocariasis common in pets/humans in the uK
- most people who swallow the eggs of toxocara spp do not become ill
- it is rare that they cause disease but common to ingest
how is toxocariasis treated in dogs
- anthelmintics
- regular disposal of dog/cat feces
for humans:
- wash hands regularly, especially before eating
- wear gloves when gardening
- teach young children not to eat soil or sand
- wash vegetables before eating them
- pick up and bin dog and cat poo quickly
- make sure pet dogs and cats are de-wormed regularly
if a child gets infected from a dog with toxocariasis, are the parents at risk
no - it is not spread between humans. the parents are only at risk if they have been handling feces/soil/sand that has been contaminated without washing hands after and even then, it is rare that disease is caused in humans
what is trichinosis
infection caused by eating raw meat infected with trichinella spiralis
Outline the cycle of Trichinella spiralis .Based on the cycle and the epidemiological situation in the UK, do you think the wild boar would be riskier than the back yard pigs?
trichinella is relatively rare in the UK (no human cases reported as a cause of meat produced in the UK in the last 40 years (strict rules on prok production) however wild boars are more likely to have because they are more likely to scavenge and eat infected meat. back yard pigs are usually fed controlled diets and are more frequently treated with anthelmintics
Which preventative measures would you advise a pig farmer to reduce the risk of their pigs from being infected with Trichinella spiralis
- controled feeding
- rodent control
- biosecurity measures (wildlife exclusion)
- regular health checks
- proper disposal of carcasses
- liscened slaughter houses and meat inspection
are pigs tested for trichinella in the UK
Pigs and horses are routinely monitored at abattoir for the presence of trichinella.
What is neurocysticercosis?
Neurocysticercosis is a parasitic infection of the central nervous system caused by the larval stage of the pork tapeworm, Taenia solium when humans become the accidental intermediate host
Why is neurocysticercosis not common in the UK and where is it most common in the world?
uk has strict sanitation regiments, regulated pork industry, high health awareness, and effective waste management
more common in developing countries: latin america, sub-saharan africa, southeast asia
outline the life cycle of neurocysticerosis and what is the most likely source of zoonotic infection
Humans are usually exposed to eggs by ingestion of food/water contaminated with feces containing these eggs or proglottids or by person-to-person spread. Tapeworm carriers can also infect themselves through fecal-oral transmission (e.g. caused by poor hand hygiene).
NOT EATING UNDERCOOKED PORK (which causes intestinal taeniasis)
can neurocysticercosis be treated?
yes - with anti parasitices but sometimes requires surgery
which measures can prevent neurocysticercosis
- hygiene practices
- avoiding ingesting anything that might be contaminated (water, food, esp raw)
why is treatment with praziquantel so important for animals who enter the uK from another country
- prevents tapeworm infection by echinococcus spp
- the UK is free of Echinococcus multilocularis (a zoonotic parasite!)
