parasitic infection

Question 1

define infection

Answer 1

invasion by and growth of
pathogenic microorganisms
within the body

Question 2

define disease

Answer 2

a disordered or incorrectly functioning
organ, part, structure, or system of
the body resulting from the effect of
genetic or developmental errors,
infection, poisons, nutritional deficiency
or imbalance, toxicity, or unfavorable
environmental factors; illness;
sickness; ailment.

Question 3

what is a parasite?

Answer 3

organism living in or on the host and
dependent on the host for nutrition - causing
damage

Question 4

what are the 2 different types of parasites?

Answer 4

endoparasites; protozoa, metazoa

ectoparasites

Question 5

what is a protozoa? give an example

Answer 5

single celled organism

amoeba, coccidiae, ciliae, flagellates

Question 6

what is a metazoa?

give an example

Answer 6

multicellular orgamisms

roundworms, flatworms, flukes

Question 7

what are the 2 different types of amoeba?

Answer 7

•   Entamoeba histolytica

*   Entamoeba dispar

Question 8

give 3 examples of coccidia and the diseases they cause

Answer 8

plasmodium –> malaria
toxoplasma –> toxoplasmosis
cryptosporidium –> diarrhoea

Question 9

what are the main symptoms of malaria?

Answer 9

Fever, headache, chills, vomiting, muscle pain
Paroxysm (cycle in 4-8hrs)

Complications of malaria:
Severe anemia (destruction of red cells)
Cerebral malaria (swelling of the brain,seizures, coma)

liver failure
Shock 
Pulmonary edema
abnormally low blood sugar 
kidney failure
swelling and rupturing of the spleen

Question 10

how might someone get infected by toxoplasma?

Answer 10

Humans can become infected by any of several routes:
• eating undercooked meat of animals harboring tissue cysts
• consuming food or water contaminated with cat feces
• by contaminated environmental samples
• blood transfusion

Question 11

what are the concequenses of toxoplasma infection?

Answer 11

worse in immuncocompromised patients

Immunocompromised patients may develop central nervous system disease, brain lesions, pneumonitis or retinochoroiditis among other risks.

Question 12

what are the symptoms of cryptosporidium

Answer 12

Causes diarrhoea, fever, nausea, vomiting in humans; very common in HIV+ patients presenting with diarrhoea.

Question 13

give an example of a ciliate?

Answer 13

balantidium coli

Question 14

what are the symptoms of balantidium coli infection?

Answer 14

symptomless in most people
–> problem as may stay in person for a long time undetected

Immunocompromised patients may experience more severe signs and symptoms: persistent diarrhea, dysentery, abdominal pain, weight loss, nausea, and vomiting. If left untreated, perforation of the colon can occur.

Question 15

give an example of a flagellate

Answer 15

giardia lamblia

trichomoniasis (sexually transmitted)

Question 16

what are the symptoms of giardiasis?

Answer 16

Acute symptoms: 
Diarrhea
Greasy stools that tend to float
Stomach or abdominal cramps
Upset stomach or nausea/vomiting
Dehydration (loss of fluids)

Question 17

what are the symptoms of trichomoniasis infection?

Answer 17

Females10-50% are asymptomatic.
=> vaginal discharge, vulval itching, dysuria, or offensive odour, but these are not specific for TV.
Occasionally the presenting complaint is of low abdominal discomfort or vulval ulceration.

Males
15 to 50% of men are asymptomatic
=> discharge and/or dysuria.

ComplicationsDetrimental outcome on pregnancy and is associated with preterm delivery and low birth weight.

Question 18

what are some different examples of parasitic worms?

Answer 18

•   Roundworms (Nematodes): Ascaris, hookworm, Filaria, Strongyloides
•   Flatworms (Cestodes): Taenia (Tapeworms)
•   Flukes (Trematodes): Schistosoma

Question 19

what are the symptoms of ascarasis infection?

Answer 19

often symptomless
large number: abdominal pain, intestinal obstruction
larvae may cause localised reaction in organs

Question 20

what are the main symptoms of hookworm infection?

Answer 20

iron deficiency anaemia- caused by blood loss at site of intestinal attachment
cardiac complications
GI and nutritional/metabolic symptoms
resp symptoms

Question 21

what are the symptoms of taenia infection?

Answer 21

Most people => no symptoms or mild symptoms. Patients with T. saginata taeniasis often experience more symptoms (size of the worm up to 10m) that those with T. solium or T. asiatica (~3 m).

Tapeworms can cause digestive problems including abdominal pain, loss of appetite, weight loss, and upset stomach.
The most visible sign of taeniasis is the active passing of tapeworm segments

Question 22

what is the most common cause of aquired epilepsy worldwide?

Answer 22

taenia solium infection

Question 23

give an example of a trematode (fluke)

Answer 23

schistosomiasis

Question 24

what are the symptoms of schistosomiasis

Answer 24

Within days: possible rash or itchy skin. Within 1-2 months; fever, chills, cough, and muscle aches but most people have no symptoms at this early phase of infection.

eggs produces travel to intestines, liver or bladder causing inflammation or scarring

repeatedly infected children : anaemia, malnutrition, learning difficulties

Question 25

what is an ectoparasite?

Answer 25

parasite that lives on the outside of the host

Question 26

give some examples of ectoparasites

Answer 26

Pediculus humanus capitis (head louse),

Pediculus humanus corporis (body louse, clothes louse)

Pthirus pubis (“crab” louse, pubic louse)

Question 27

what are examples of diseases caused by Leishmania parasite?

Answer 27

Visceral Leishmaniasis

cutaneous leishamaniasis

diffuse cutaneous
leishmaniasis

mucoocutaneous/ mucosal leishmaniasis