L32 - Intro To Helminths And Protozoa Flashcards
1
Q
What are protozoa? (2)
A
- diverse group if sinlge celled “animal like” eukaryotes
- part of protists
2
Q
What are protozoa like? (2)
A
- most free living, some are pathogens
- prevalent in (sub)tropical regions
3
Q
What do protozoa do? (3)
A
- infect tissues/organs
- intracellular parasites in cells
- extracellular in blood, intestine, urogenital system
4
Q
How are protozoa transmited? (2)
A
- vectors // malaria
- contaminated water/soil/food //amoeba
5
Q
What do protozoal cells have (organelles, structures)? (6)
A
- mitochondria
- ER
- golgi apparatus
- food vacuole
- contractile vacuole
- pseudopodia
6
Q
What is the classification of protozoa? (4)
A
- amoeba - move by pseudopodia
- flagellates - have flagella
- ciliate - have cilia
- apicomplexa (sporozoa) - have apical complex, all parasitic // plasmodium
7
Q
What are facts about malaria? (4)
A
- bad air, also called marsh fever
- > 100 countries, tropical areas (africa, asia and south america)
- 40% world at risk, 90% of deaths in africa
- deaths dec over last 5-10 yrs (due to prevention strategies, new drugs)
8
Q
What are malaria - causative agents from less common and moderate disease to more common and severe disease? (4)
A
- plasmodium malariae
- plasmodium ovale
- plasmodium vivax
- plasmodium falciparum
9
Q
What is the life cycle for malaria? (4)
A
- parasite injected with saliva of blood-feeding female mosquitoes
- multiply in liver (~2 weeks)
- released - infect RBCs repeatedly (days)
- go through reproductive phase inside mosquito
10
Q
What are uncomplicatedsymptoms of malaria? (5)
A
- 6-10 hours
- cold stage - shivering
- hot stage - fever
- sweating stage
- headache, body ache, nausea, vomiting, weakness, enlarged spleen
11
Q
What are severe (complicated) symptoms of malaria? (6)
A
- cerebral malaria - abnormal behaviour, seizures, coma
- shock (drop in blood flow)
- severe anaemia (haemolysis)
- pulmonary oedema (breathing problems)
- liver failure, jaundice
- swelling, rupturing of spleen
12
Q
What is chemoprophylaxis like in areas without drug resistance? (2)
A
- chloroquine
- proguanil
13
Q
What is chemoprophylaxis like in areas with limited drug resistance?
A
Proguanil plus chloroquine
14
Q
What is chemoprophylaxis like in areas of chloroquine resistance? (3)
A
- mefloquine
- doxycycline
- atovaquone-proguanil
15
Q
What are general feautres of helminths (structure)? (4)
A
- multicellular, differentiated organs (no circulatory tract)
- <1 mm to >10 m
- anterior end, have suckers, hooks, plates (used for attachment)
- touch cuticle - difficult for immune system to eradicate
16
Q
What are general features of helminths (facts)? (3)
A
- most worms dont have full life cycle (replicate free, weight of infection prop. To num of infecting organisms)
- some camouflage by coating with host molecules
- feed on body fluids or intestinal contents
17
Q
What are the 3 main classes of helminths? (3)
A
- nematodes (roundowmrs, cylindrical, alimentary canal)
- cestodes (tapeworms, flat, ribbon, no digestive tract - nutrients through cuticle)
- trematodes (flukes, leaf-shaped, blind-branched alimentary tract)
18
Q
What are the types of nematodes? (4)
A
- large roundworm
- threadworm
- hookworm
- whipworm
19
Q
What is the transmission and symptoms of large roundworm? (2)
A
- fecal-oral
- heavy infection - slows development, shortness of breathm coughing, malnutrition, blockage intestines
20
Q
What is the transmission and symptoms of threadworms? (2)
A
- fecal-oral
- mild anal itching
21
Q
What is the transmission and symptoms of hookworms? (2)
A
- larvae in soil penetrate skin
- slows growth and development, anaemia
22
Q
What is the transmission and symptoms of whipworms? (2)
A
- fecal-oral
- usually asymptomatic, heavy infection, bloody diarrhoea
23
Q
What are adult worms of ascariasis like?
A
10-30 cm
24
Q
What are infections like with ascariasis? (5)
A
- max intensity infection in children at 5-10 yr
- migration of larvae to the lungs causes most of the damage
- heavy infection - abdominal pain, malnutrtition, escape from anus, mouth, nose or ears
- severe infection - blockage of intestines
- adults parasites migrate
25
What is the cycle of tissue nematodes in blood? (6)
- adults in tissue/lymphatic system
- microfiliariae circulate in blood
- ingested with blood meal by arthropod
- dev into infectious stage (L3)
- enter skin when arthopod feeds
- migrate and develop in tissue
26
What is lymphatic filariasis (elephantiasis)?
Damage to lymphatic system and fluid build up = results in enlargement of parts of body
27
What is onchocerciasis (river bilndness)?
Micrifiariae enter internal tissue of eye
= inflammation, bleeding = blindness
28
What is loiasis?
Adult loa loa worm travels through subcutaneous tissues
= inflammation in the skin and eye
29
What are facts about cestodes? (3)
- >10m, live dor decades
- humans as primary host - ingestion of cyst from undercooked meat/fish - worm in lumen
- secondary host - ingestion of egg, develop into larva that invades tissue
30
What are facts about trematodes (flukes)? (3)
- live for decades in tissue or blood vessels
- progressive damage to vital organs
- snail as intermediate host = secondary host
31
What are the different types of flukes? (2)
- lung fluke - eating infected crab and crayfish
- liver fluke - freshwater fish
32
What are schistosomiasis? (3)
- worms 0.6-2.6cm
- contamination through infected water
- // bilharzia, snail fever
33
What are symptoms of schistosomiasis? (4)
- days - develop rash/itchy skin (swimmers itch)
- 1-2 months - fever, vhills, cough, muscle aches
- main damage - eggs stuck in tissues
- organ damage from inflammation and scarring // liver, intestines, lungs, bladder = bladder cancer
34
What is the diagnosis for helminths? (3)
- intestinal nematodes/cestodes - eggs/larvae in faceal sample/ incidental diagnosis
- schistosomas - eggs/larvae in faecal sample or urine
- tissue nematdodes - adults in tisssue, microfilaria in blood
35
How could helminths be used as therapeutics? (4)
- not declared bc they are able to modulate immune system
- nematode infection protects against allergic disease
- // Gi nematode lead to reduced skin reactivity to dust mite allergen
- // inverse correlation between incidence of asthma and hookworm infection
