parasitic infections

Question 1

what are the two classes of parasitic infections

Answer 1

endoparasites

ectoparasites

Question 2

what subclasses come under endoparasites

Answer 2

protozoa

metazoa

Question 3

what is an endoparasite

Answer 3

organism living INSIDE a host

Question 4

what is an ectoparasite

Answer 4

organism living ON a host

Question 5

what is a protozoan and give the different categories

Answer 5

single cell organism- eukaryotic- do NOT cause eosinophilia - some have insect vectors

Amoebae, coccidia, ciliates, flagellates

Question 6

what is a metazoan and give the different categories

Answer 6

multi-cellular organism- some inhabit gut, others invade tissues- eosinophilia if they invade the blood.
Adult worms cannot multiply in humans- number of worms correlates to infection

roundworms, flatworms, flukes

Question 7

what are the different examples of Amoebae and their main symptoms

Answer 7

Entamoeba dispar- normal commensal bacteria of GIT

Entamoeba histolytica- infects 10% of population and 10%is pathogenic, causes amoebiasis; faeco-oral route of transmission- can cause bloody diarrhoea and liver abscess

–Cause ulcers

Question 8

what are the different examples of Coccidia

Answer 8

Coccidia: mainly zoonoses

Plasmodium species:- malaria

Toxoplasma gondii-toxoplasmosis

cryptosporidium

Question 9

what are the different examples of ciliates and their main symptoms

Answer 9

Balantidum coli: causes balantidiasis

reservoir hosts: pigs, rodents, primates
symptoms: mostly asymptomatic, in immunocompromised = persistent diarrhoea, dysentery, abd pain weight loss, nausea, emesis all leading to perforation of colon

diagnosed via stool examination

Question 10

what are the different examples of Flagellates and their main symptoms

Answer 10

Giardia lamblia– diarrhoea

Trichomonas vaginalis– mostly asymptomatic (10-50% F, 15-50% M), if no: discharge and/or dysuria–sexually transmitted

leishmania-transmitted by sand flies

• cutaneous leishmaniasis – skin disease, localised ulcers- -visceral leishmaniasis – fever, weight loss, hepatosplenomegaly
• diffuse cutaneous- leprosy / skin lesions
• mucocutaneous- disfigurement as destroys much membranes

Question 11

give the main symptoms, causes and facts about: plasmodium species

Answer 11

Plasmodium species:- malaria

• 2 hosts (human and female anopheles mosquito.
• 2 stages: blood and liver
• fever, headaches, chills, emesis, myalgia aka muscle pain
• complications=severe anaemia, cerebral malaria, renal failure

(class: protozoa, coccidia)

Question 12

give the main symptoms, causes and facts about: toxoplasma Gondii

Answer 12

Toxoplasma gondii-toxoplasmosis

• major disease in pregnant
• caused by: infected food (aka undercooked meats) or cat faces contamination, blood transfusion, trans placental transmission, organ transplant
• symptoms: can cause CNS infection in immunocompromised- retinochoroiditis

(class: protozoa, coccidia)

Question 13

give the main symptoms, causes and facts about: cryptosporidium

Answer 13

cryptosporidium:

• symptoms: diarrhoea, fever, nausea, emesis
• very common in HIV patients
• treatment = fluid rehydration

(class: protozoa, coccidia)

Question 14

what are the different examples of roundworms/nematodes and their main symptoms

Answer 14

Ascaris- often asymptomatic, abdo pain, obstruction, malnourishment, Loeffler’s pneumonia

hookworm-iron deficiency anaemia, local skin manifestations, respiratory symptoms, cardiac complications

filaria- cause elephantiasis

strongyloides-dermatitis, diarrhoea

whipworm-trichuris trichuria- bloody diarrhoea, anaemia, vitamin/mineral loss

Loa Loa- these can get into the eye, can live fro 4-12 years
vector: Chrysops
confined to africa

Question 15

what are the different examples of Flatworms/cestodes and their main symptoms

Answer 15

Tapeworm (Taenia)- humans only host

• Taenia solium (pig) – cysticercosis (acquired epilepsy)
• Taenia asiatica (pig)
• Taenia saginata (beef) - abdominal pain, loss of appetite, weight loss

most people are asymptomatic

treatment: praziquantel
diagnosis: segements of worm in stools

Question 16

what are the different examples of Flukes/Trematodes and their main symptoms

Answer 16

Schistosoma mansoni, 
Schistosoma japonicum (small intestine), 
Schistosoma haematobium (bladder, ureter)

• carried by snails- schistosomiasis
  symptoms:
  -early: rash, muscle aches, most asymptomatic
• Later: learning difficulties, malnutrition, fever, chills, cough,

diagnosis: stool/ urine anaylsis
treatment: Praziquantel

Question 17

What are the main examples of ectoparasites and their symptoms

Answer 17

scabies- Sarcoptes scabei

symptoms: rash and burrows presence

Lice:

• Pediculus humanis corporis: body louse
• Pediculus humanis capitis: head louse
• Pthirus pubis: pubic louse

transmission by direct contact

Question 18

define vector and give examples

Answer 18

an organism that transmits a desires or parasite from one organism to another

Eg:

• Snail: schistomiasis
• Female anopheles mosquito: malaria (plasmodium species)
• Chrysops: transmits Loiasis (Loa Loa)