Parasitic Infections Flashcards
What are Protozoa?
Diverse group of single celled animal-like eukaryotes
Where are Protozoa prevalent?
(Sub)tropical regions
What are the four classifications of Protozoa?
Amoeba
Flagellates
Ciliates
Apicomplexa
What Protozoal diseases can affect the CNS?
Amoeba
Malaria
Toxoplasma
Trypanosomes
What Protozoal diseases can affect the blood?
Malaria
Trypanosomes
What Protozoal diseases can affect the liver?
Entamoeba
Leishmania
What Protozoal diseases can affect the skin?
Leishmania
What Protozoal diseases can affect the intestine?
Cryptosporidium
Entamoeba
Giardia
Isospora
Where is malaria mainly found?
Africa, Asia and South America
What Protozoal diseases can affect the CNS?
Amoeba
Malaria
Toxoplasma
Trypanosomes
What Protozoal diseases can affect the blood?
Malaria
Trypanosomes
What Protozoal diseases can affect the liver?
Entamoeba
Leishmania
What Protozoal diseases can affect the skin?
Leishmania
What Protozoal diseases can affect the intestine?
Cryptosporidium
Entamoeba
Giardia
Isospora
How many cases of malaria are there in the U.K. per year?
1,500-2,000
What are the four causes of malaria in humans?
P.falciparum
P.vivax
P.ovale
P.malariae
What are the uncomplicated symptoms of malaria?
6-10 hours of: -cold stage- shivering -hot stage-fever -sweating stage Other:headache, body aches, nausea, vomiting, weakness, enlarged spleen
What are the complicated symptoms of malaria?
Cerebral malaria- abnormal behaviour, seizures, coma Shock Severe anaemia Pulmonary oedema Liver failure Swelling, rupturing of spleen
What is the malaria ABCD?
Awareness of risk
Bite prevention
Chemoprophylaxis
Diagnosis and treatment
What malaria chemoprophylaxis should be used in areas without drug resistance?
Chloroquine
Proguanil
What malaria chemoprophylaxis should be used in areas of little chloroquine resistance?
Proguanil plus chloroquine
What malaria chemoprophylaxis should be used in areas of chloroquine resistant P.falciparum?
Mefloquine
Doxycycline
Atovaquone-proguanil
How can malaria be diagnosed?
Blood smears
Rapid diagnostic tests
PCR, antibody detection, mass spec
What is the treatment for malaria caused by P.falciparum?
Quinine followed by doxycycline or clindamycin
Atovaquone-proguanil
Arthemether-lumefantrine
What is the treatment for malaria caused by P.vivax or P.ovale?
Chloroquine followed by primaquine
What is he mode of action for proguanil, pyrimethamine and sulphadoxine?
Antifolate
What is the mode of action for chloroquine, lumefantrine and mefloquine?
Inhibits harm detoxification
What is the mode of action for atovaquone?
Inhibits mitochondrial metabolism
How is the malaria vaccine engineered?
From parts of surface protein of P.falciparum and fused to surface antigen from hep B to boost immune response
what are helminths?
Multicellular with differentiated orgains
What parasitic infection does not have its full life cycle in humans?
helminths
Why are helminths difficult for the immune system to eradicate?
they have a tough cuticle
Name an example of an helminth which camouflages by coating with the host molecules?
Blood flukes
What do parasitic helminths feed on?
body fluids or intestinal contents
Where are helminths mainly found?
Rural villages/overcrowded cities in tropics
What symptom can helminths cause?
malnutrition
What are the three main classes of helminths that infect humans?
Nematodes (roundworm)
Cestodes (Tapeworms)
Trematodes (Flukes)
What do nematodes look like?
Cylindrical body, alimentary canal
What do cestodes look like?
Flat, ribbon shaped, no digestive tract
What do trematodes look like?
leaf-shaped, blind branched alimentary tract
How are large roundworm transmitted?
Fecal-oral
What symptoms do large roundworm give?
slows development, shortness of breath, coughing, malnutrition, blockage intestines
How are threadworm transmitted?
Fecal-oral
What symptoms do threadworm give?
mild anal itching
How are hookworm transmitted?
larvae in soil penetrate skin
what symptoms do hookworm give?
slows growth and development, anaemia
How are whipworm transmitted?
Fecal oral
What symptoms do whipworm give?
usually asymptomatic but heacy infection can cause bloody diarrhoea
Ascariasis is caused by what?
Roundworm
What are the symptoms of ascariasis?
abdominal pain, malnutrition
How many eggs do mature female ascariasis produce per day?
> 200,000
Name the 7 steps of te ascariasis life cycle
- Produce eggs
- eggs excreted in faeces
- eggs mature in soil
- eggs ingested
- larvae hatch in small intestine and penetrate wall
- enter blood and carried to organs
- coughing brings larvae into intestines where they mature
What are nematodes?
roundworms
What are cestodes?
Tapeworms
What are trematodes?
Flukes
What does lymphatic filariasis/ elephantiasis cause?
Enlargement of body parts
What does onchocerciasus/river blindness cause?
inflammation of the eye leading to blindness
What does loiasis cause?
Inflammation in the skin and eye
What usually causes tapeworm?
ingestion of cust from undercooked meat/fish
What do trematodes cause?
Progressive damage to vital orgains
What do trematodes use as their intermediate host?
Snail
What are lung fluke caused by?
Eating infected crab and crayfish
What are liver fluke caused by?
Freshwater fish
What is the 2nd greatest economic impact of parasitic diseases?
Schistosomiasis
What are Schistosomiasis caused by?
blood flukes through infected water
What are the symptoms of Schistosomiasis?
Rash
1-2 months: fever, chills, cough, muscle aches
organ damage
What is the lifecycle of Schistosomiasis?
Larvae in water infect snail Snail forms larvae Larva penetrate skin of human Migrate to liver Mature and form male:female pairs to final destination
How many eggs do femal Schistosomiasis produce per day?
300
How are intestinal nematodes/cestodes diagnosed?
Eggs detected in faeces
How are Schistosomas diagnosed?
eggs in faecal sample or urine
How are tissue nematodes diagnosed?
Adults in tissue, microfilaria in blood
What is Ivermectin used to treat and what’s its MoA?
Filarial nematodes
Blocks ion channels in neurons, leading to paralysis
What are albendazole & mebendazole used to treat and MoA?
Intestinal nematodes
Blocks microtubulin assembly, inhibits glucose uptake
What is niclosamide used to treat and its MoA?
Tapeworms
Uncouples oxidative phosphorylation
What is piperazine used to treat and its MoA?
Roundworms, threadworms
Blocks neurotransmitter-paralysis, often used with sennosied
What is praziquantel used to treat and its MoA?
Flukes, tapeworms
Alters calcium permeability, paralysis