Parasitology Flashcards
What are ticks a major vector of?
Rickettsia
And other viruses, bacteria and protozoan
When is Toxoplasmosis must dangerous?
Acute infection in pregnant women
Immunosuppressed people
Under what circumstances can *Ascaris *infection be ruled out?
If a person hasn’t been to an endemic area for over 2 years
How do you diagnose giardiasis?
Cysts in faeces
IgA serology in faeces
What type of lifecycle does *Echinococcus *have?
Predator-prey
Where in the body does *Schistosoma *mature?
In the portal circulation
How do human become infected with Taenia?
Consumption of cysts in uncooked meat
Which tick species is the most important in terms of human disease in Australia?
Ixodes holocyclus
How do you treat Echinococcus cysts?
Surgery
PAIR
Antihelminths
What is the name of the new treatment for lice?
Topical ivermectin
What does tick paralysis sometime resemble?
Guillain-Barre Syndrome
How do you prevent tick infestation?
Protective clothing
Repellent
Body inspection after walking
How do you control amoebiasis?
Clean drinking water
Sewage treatment
What is the clinical history of amoebic cysts?
Prolonged diarrhoea followed by cyst symptoms
What makes you scratch in lice infestations?
Lice aand moults are irritants
How is schistosomiasis acquired?
Swimming in frest water (cercaria penetrate skin)
How many eggs can a Ascaris lumbricoides female lay per day?
200,000
Where does Sarcoptes scabiei prefer to infest?
Fingerwebs
Elbows
Axillae
Genitals
What are the symptoms of schistosomiasis?
Light infection: dermatitis, asymptomatic
Heavy infection: Splenomegaly, hepatomegaly, collateral circulation, portal hypertension, pulmonary fibrosis
Is the most important fluke (trematode) infection?
Schistosoma mansonii
How is *Toxoplasma gondii *transmitted?
Ingestion of cyst in water, cat faeces or uncooked meat
How can you diagnose *Ascaris *infection?
Eggs in faeces
What are some diagnostic techniques for Strongyloides?
Serology
Eggs in faeces
What are some disease control strategies for schistosomiasis?
Sewage treatment
Kill snails
Treat carriers
Where does Toxoplasma gondii infect?
Intracellularly
Form cysts in tissue
Which worms undergo a tracheal migration?
- Ascaris*
- Strongyloides*
Where do *Ascaris *eggs hatch?
In the GIT of host after maturing outside
How is toxoplasmosis diagnosed?
Serology
What is the pre-patent period of Enterobius?
4-6 weeks
Name three species of lice and their site of infestation
Pediculus capitis
Pediculus humanis
Phthuris pubis
Which worm can perform immunological masking to avoid the immune response?
Schistosoma
How many eggs can female lice lay per day?
3-9
What are some control stategies for Strongyloides?
Sewage treatment
Wear shoes
What disease control techniques are available for Taenia?
Treat carriers
Avoid uncooked pork
Sewage disposal
Hygiene
Vaccination of pigs
What do Echinococcus cyst common occur?
Lung
Liver
Is lice infestation greater in people with poor hygiene?
No
What is the name of lice infestation?
Pediculosis
What is a paratenic host?
A host in which the parasite can enter, not undergo sexual reproduction but remain infectious
How do you diagnose E. histolytica?
Serology
Faecal cysts
(Imaging for cysts)
What is the treatment for giardiasis?
Tinidazole
How is E. histolytica transmitted?
F-O: usually water
Where does *Entamoeba histolytica *infect in the host?
Colon
Can invade and form cysts in the liver or brain
What are two tapeworms?
Taenia
Echinococcus
How does *Echinococcus *cause disease?
Adult leaves the GIT and encysts in tissue
How does *Emtamoeba histolytica *travel around the body?
Haematogenous spread
Why is treatment for *Taenia *with anti-helmintics sometimes bad?
It can stimulate a immune response and lead to epileptic fits
What are the symptoms of giardiasis?
Diarrhoea
Chronic or acute malabsorption
What is happening to the prevalence of Phthuris pubis?
It is decreasing
Can you do serological testing for giardiasis?
Only IgA in the faeces as *Giardia *doesn’t get into the circulation to cause a systematic immune response
How is *Strongyloides *transmitted?
Direct penetration of host by larvae (usually feet)
Which helminth doesn’t require a second host?
Strongyloides
What do you treat amoebiasis with?
Metroniazole + paromomycin
Abscess drainage
How many eggs does the *Strongyloides *female produce per day
50
What are the symptoms of *Ascaris *infection?
Asymptomatic mainly
Can cause pneumonitis or intestinal blockage (pancreatitis, cholangitis
Where is Ixodes holocyclus distributed in Australia?
Eastern coast
What is a common zoonotic host of *Giardia intestinalis *in Australia?
Possums - they can contaminate water supplies
What are larval cysts of *Echinococcus *called?
Hydatid cysts
What is a complication of *Strongyloides *infection in the immunosuppressed?
Gram negative disease - larval migration take gram negatives with them - cause secondary infection outside GIT, septicaemia
How is Pediculus humanis spread?
On clothing
Which Taenia species causes neurocystocercosis
solium
What type of parasite is Emtamoeba histolytica?
Protozoan, Amoeba
How to diagnose Taenia?
Serology
Imaging
In which worm infection does autoinfection occur?
Enterobius
Strongyloides (new eggs hatch in GIT before being excreted)
What are diseaes control methods for Echinoccocus?
Hygiene
Vaccine livestock
Prevent infection in dogs
How can Ascaris cause asthma like symptoms?
Tracheal migration through the lungs
How many eggs can Taenia produce per day?
300,000
Where does embryonation of A. lumbricoides occur? How long does it take?
In soil
2-4 weeks
What are the two types of paralysis that ticks can cause?
Local or generalised (like Guillain-Barre)
What are three types of roundworms?
Pinworms (Enterobus vermicularis)
Strongyloides sterceralis
Ascaris lumbricoides
