6 LIFECYCLES

Question 1

Toxoplasma gondii:

Answer 1

• Toxoplasmosis

- Single cell organism (no male or female)

Question 2

Toxoplasma gondii geographic location:

Answer 2

France and Central America

Question 3

Modes of infection of Toxoplasma gondii: (3)

Answer 3

• Eating undercooked meat of animal that has cysts
• Litter box
• Blood transfusion or organ transplant

Question 4

Toxoplasma gondii

Definitive host:
Intermediate host:

Answer 4

Cat

Humans, dogs, mice, cow, sheep, pig

Question 5

Toxoplasma gondii mode of transmission: (3)

Answer 5

Cat defecates (unsporulated oocyst in feces)-> rat eats oocyst-> cat eats rat-> intestinal cycle in cats only

Question 6

Plasmodium:

Answer 6

• Malaria

- Causes recurrent fever when RBC pop and release parasites

Question 7

Plasmodium geographic location:

Answer 7

Tropical regions such as South America, Asia, Africa

Question 8

Plasmodium

Vector:
Intermediate host:

Answer 8

Mosquito (female)

Humans

Question 9

Plasmodium transmission:

Answer 9

Female mosquito-> sporozite-> liver-> RBC (trophozoite)-> other RBC (merozite)-> schizont-> merozoites

Question 10

Taenia solium: (3)

Answer 10

• Causes Teaniasis disease
• Pork tapeworm
• Leading cause of epilepsy and cysticercosis (cysts in brain)

Question 11

Taenia solium geographic location:

Answer 11

-South America and Central America

Question 12

Taenia solium mode of transmission:

Answer 12

Gravid proglottid in fecal matter-> pig-> oncosphere penetrates intestinal wall-> forms cyst in pig in muscle -> human eats undercooked pork-> adult worm attaches to small intestine via scolex->gravid proglottid-> ingested by human-> causes autoinfection-> oncosphere hatches and penetrates intestinal wall-> circulation-> cyst (brain, lung, eye, c.t.)

Question 13

Definitive host in Taenia solium:

Intermediate host:

Answer 13

Humans

Pig

Question 14

Taenia saginata:

Answer 14

Causes Taeniasis Disease
Beef tapeworm
IH: cattle

Question 15

Ascaris:

Answer 15

• Human roundworm
• Largest nematode
• Most common human helminthic infection

Question 16

Ascaris geographic location:

Answer 16

Tropical regions with poor sanitation

Rural areas of Southeastern US

Question 17

Ascaris mode of transmission:

Answer 17

Eggs shed in fecal matter-> egg dormant and can survive w/o water-> ingested by human (def host)-> hatch in intestines and get into bloodstream-> lungs, trachea-> pharynx-> swallowed-> female lay eggs, male fertilize eggs

Question 18

Diphylobrothriasis:

Answer 18

• Broad fish tapeworm

- Cestodes have a scolex instead of suckers

Question 19

Diphylobrothriasis geographic location:

Answer 19

East Asia and South America

Question 20

Diphylobrothriasis mode of transmission:

Answer 20

Unembryonated egg passes in feces-> water embryonate-> egg hatches and eaten by crustaceans-> gets ingested by small fish (infected stage)-> predator fish eats small infected fish-> human eats fish-> infects adults small intestine

Question 21

Diphylobrothriasis

Definitive host:
Intermediate host:

Answer 21

Humans and fish-eating mammals

Crustaceans and small fish

Question 22

Anisakis:

Answer 22

• Anisakiasis Disease

- Ingestion of larvae of nematodes (roundworms)

Question 23

Anisakis geographic location:

Answer 23

Japan, South America, Netherlands

Question 24

Anisakis mode of transmission:

Answer 24

Marine mammals excrete unembryonated eggs-> water embryonate-> larvae hatches from eggs and is free-swimming-> larvae ingested by crustaceans-> crustaceans eaten by fish and larvae transferred from fish to fish-> infects marine mammals and humans

Question 25

Incidental host of anisakis?

Answer 25

Humans when eating infected raw or undercooked seafood