Parasitic Pathogenesis

Question 1

Give some examples of parasite pathogenesis

Answer 1

Hydrolytic enzymes
Amoebic ionophore
Endotoxins
Protein-losing entheropathies

Question 2

Characteristics of malaria

Answer 2

Caused by plasmodium parasites carried by female anopheline mosquitoes.

• can live in liver and blood of humans
• mosquito is definitive host to parasite, male is intermediate host

Question 3

What symptoms does the multiplication of parasites within erythrocytes cause

Answer 3

Anaemia
Splenomegaly (enlargement of spleen)
Fever up to 40 degrees
Severe coma, often death

Question 4

True or false: nephrotic syndrome is a complication of malaria as well as jaundice

Answer 4

True

Question 5

Treatment of malaria

Answer 5

• Alkaloid quinine is the main antimalarial drug
• chloroquine kills merozites within erythrocytes but not sportizoites, merozoites or gametes outside cells which can be killed by primaquine
• I’m case of resistance, mefloquine or doxycycline are used

Question 6

What is amoebiasis

Answer 6

Infection with entamoeba histolytica, water residing parasite.
2 forms
- vegetative form
- Trophozoite - able to divide

Question 7

What is the appearance of cysts

Answer 7

4 nuclei packed in a dense cell

Question 8

Diagnosis of amoebiasis

Answer 8

Presence of cysts In stool

Question 9

Characteristics of a trophozoite

Answer 9

Motile containing ingested erythrocytes, moves like rolling bag of marbles

Question 10

Characteristics of entemoeba histolytica infection

Answer 10

• Trophozoite causes diarrhoea
• proteinase degrading epithelial Membranous and cell-anchoring proteins, disrupting epithelial layers
• phospholipids and ionophore-like proteins that lyse host neutrophils releasing neutrophil toxic substances

Question 11

Characteristics of liver abscess

Answer 11

The material aspirate produces from amoebic liver abscesses have characteristic reddish tinges and smells. Consist of necrotic tissue as a result of proteolytic enzymes.
- radiological scan shows elevation of diaphragm

Question 12

What is toxoplasmosis

Answer 12

Infection with protozoan Toxiplasma gondii

Question 13

Characteristics of toxiplasmosis

Answer 13

Infection common, disease rare, commonly involves CNS

• characteristic of AIDS patients
• maternal toxiplasmosis can spread to foetus
• exists in 3 forms, Tachyzoite, tissue cyst and faecal cyst

Question 14

How can toxiplasmosis manifest

Answer 14

Localises in CNS so hydrocephalus etc.

Choroidoretinitis