Parasitology III-IV

Question 1

What is the severity of symptoms of the helminths infection related to?

Answer 1

The number of organisms at inoculation because they do not multiply within the human host

Question 2

What are the only helminths that reproduce in humans?

Answer 2

• Strongyloides

- Hymenolepsis nana

Question 3

What are the nematodes that are acquired by passage though the skin?

Answer 3

• Strongyloides stercoralis

- Hookworms

Question 4

What is the movement of Strongyloides though the body?

Answer 4

Penetration through the skin is followed by relocation to the lungs and ends up in the intestines

Question 5

Why is Strongyloides a chronic infection?

Answer 5

Due to its ability for autoinfection

Question 6

How is Strongyloides diagnosed?

Answer 6

• Marked eosinophilia

- Rhabditiform larvae in stool

Question 7

What is the treatment for Strongyloides?

Answer 7

Albedazole

Question 8

What are the species of hookworm?

Answer 8

Ancylostoma duodonale

Necator americanus

Question 9

What is the difference in the life cycle of hookworms and Strongyloides?

Answer 9

Ova passed in feces - hatches to R. larva in soil whereas Strongyloides can pass larvae in the stool

Question 10

What are some symptoms of the hookworm infection?

Answer 10

Iron deficiency anemia

Question 11

How are hookworms diagnosed?

Answer 11

Ova found in feces with microcytic anemia

Question 12

What is the treatment for hookworms?

Answer 12

Albendazole

Question 13

What are the nematodes acquired by ingestion?

Answer 13

Visceral/Ocular/Neural Larva Migrans

• Ascaris lumbricoides
• Toxocara canis, Toxocara catis
• Baylisascaris procyonis

Question 14

How is Ascaris lumbricoides diagnosed?

Answer 14

• Ova/worm in the stool

- Barium x-ray

Question 15

What is the treatment for Ascaris?

Answer 15

Albendazole

Question 16

What are the nematodes that humans are accidental hosts for?

Answer 16

• Toxocara canis, Toxocara catis

- Baylisascaris procyonis

Question 17

What are the signs of V/O/N larva migrans?

Answer 17

Wandering larvae produce hemorrhage and inflammation – Eosinophilic infiltration, granulomas - humans are not the right host so worms cannot embed like in their normal host

Question 18

How are visceral larvae migrans diagnosed?

Answer 18

• Larva in tissue

- Serology

Question 19

What is the treatment for visceral larvae migrans?

Answer 19

Albendazole - none effective for Balylisascariasis

Question 20

What is the life cycle of Enterobius vermicularis (pinworm)?

Answer 20

Ova are ingested and it develops in the intestine where the female migrates to the perianal region to deposit eggs

Question 21

What are the signs of pinworm infection?

Answer 21

• Perianal and perineal itching

* GU granuloma

Question 22

How is pinworm infection diagnosed?

Answer 22

Ova demonstrated on tape from perianal area

Question 23

What is the treatment for pinworms?

Answer 23

Albendazole - there is reinfection possibility though so MUST TREAT TWICE

Question 24

Where is Trichuris tirchiura infection commonly seen in the world?

Answer 24

In the tropics

Question 25

What is the life cycle of Trichuris tirchiura?

Answer 25

Ingested ova will develop only within the intestine

Question 26

What are the signs of Trichuris tirchiura infection?

Answer 26

``` Most are asymptomatic but serious infections can have: – Diarrhea – Abdominal pain – Rectal prolapse – Anemia ```

Question 27

How is Trichuris tirchiura diagnosed?

Answer 27

Ova in feces with morphology of polar plugs

Question 28

What is the treatment for Trichuris tirchiura?

Answer 28

Albendazole

Question 29

What is the life cycle of Trichinella spiralis?

Answer 29

Infects carnivorous animals like rats, swine and bears and is acquired by ingestion of undercooked meat - enters the skeletal muscle

Question 30

What are the phases of trichinosis?

Answer 30

Phase I - diarrheal intestinal phase Phase II - migration of larvae to the muscle causing pain - often in the muscles around the eyes Phase III - recovery

Question 31

How is trichinosis diagnosed?

Answer 31

- Eosinophilia with elevated muscle enzymes - Serology - Muscle biopsy

Question 32

What is the treatment for trichinosis?

Answer 32

Albendazole - role of drug is to eliminate the adult form

Question 33

What is the cause of eosinophilic meningitis?

Answer 33

Angiostrongylus cantonensis

Question 34

How is eosinophilic meningitis acquired?

Answer 34

Ingestion of snail or snail secretions

Question 35

How is eosinophilic meningitis diagnosed?

Answer 35

Eosinophils and larvae in CSF

Question 36

What is the life cycle of lymphatic filariasis organisms?

Answer 36

– Larvae transmitted by several mosquito types | – Adults in lymphatics produce larvae which circulate in bloodstream

Question 37

What are the manifestations of lymphatic filariasis?

Answer 37

• Acute - lymphangitis and lymphadenitis – Nocturnal cough and wheezing • Chronic - lymphatic destruction – Obstruction and chronic lymphedema

Question 38

How is lymphatic filariasis diagnosed?

Answer 38

– Eosinophilia | – Bloodsmears

Question 39

How is lymphatic filariasis treated?

Answer 39

– Diethylcarbamazine/Doxycylcine

Question 40

What is the vector of Onchocerciasis?

Answer 40

Black fly Simulium - inoculates onchocerca larvae

Question 41

What are the symptoms of onchocerciasis due to?

Answer 41

Dead or dying microfilariae

Question 42

What is one possible result of Onchocerciasis?

Answer 42

Blindness if the parasite migrates to the eye - keratitis in the lens is one example

Question 43

How is onchocerciasis diagnosed?

Answer 43

– Biopsy – Skin snips - Serology

Question 44

What is the treatment for onchocerciasis?

Answer 44

Ivermectin

Question 45

What is the vector of Loa loa?

Answer 45

Tabanid fly Chrysops

Question 46

What are that manifestations of Loa loa infection?

Answer 46

- Painful Calabar swellings | - Worm in conjunctiva

Question 47

How is Loa loa diagnosed?

Answer 47

– Microfilariae in blood smear | – Adult in subcutaneous nodule or eye

Question 48

Whati s the treatment for Loa loa?

Answer 48

Diethylcarbamazine

Question 49

How is Dracunculus medinensis (Guinea worm) acquired?

Answer 49

Ingestion of copepod containing water from wells - larvae will migrate into tissue

Question 50

What are some characteristic of Guinea worm infection?

Answer 50

Blisters with chronic non-healing sores - typically on the lower extremities

Question 51

How is Guinea worm treated?

Answer 51

See worm in skin or with X-ray

Question 52

What is used to treat Guinea worm?

Answer 52

Metronidazole

Question 53

What is Taenia saginata known as?

Answer 53

Beef tapeworm

Question 54

What is Taenia solium known as?

Answer 54

Pork tapeworm

Question 55

What Diphyllobothrium latum known as?

Answer 55

Fish tapeworm

Question 56

What is Hymenolepsis nana known as?

Answer 56

Dwarf tapeworm

Question 57

What is a defining characteristic of Hymenolepsis?

Answer 57

Autoinfection - can lead to enteritis

Question 58

Cysticercosis

Answer 58

Infection with larval form of T.solium after ingestion of ova from human feces leading to cerebral effects: – Meningoencephalitis and hydrocephalus – Space occupying lesions – Seizures

Question 59

How are tapeworm infections diagnosed?

Answer 59

Ova or proglottids in the feces or MRI/X-ray with cystercercosis

Question 60

What is the treatment for tapeworms?

Answer 60

Praziquantel

Question 61

What is the treatment for cystercercosis?

Answer 61

Albendazole

Question 62

What deficiency can occur with D. latum infection?

Answer 62

Vitamin B12 deficiency

Question 63

What is Echinococcus granulosis known as?

Answer 63

Dog tapeworm

Question 64

What is the sylvatic form of the dog tapeworm?

Answer 64

E. multiocularis

Question 65

What are the clinical signs of E. granulosis?

Answer 65

Space occupying lesion in liver, lung, kidney, bone

Question 66

What are the clinical signs of E. multilocularis?

Answer 66

Spreads like a malignancy

Question 67

What is the difficulty in treatment of the dog tapeworm?

Answer 67

Surgical removal of the cyst but it is difficult to not break open the contents

Question 68

What is the life cycle of Schistosoma?

Answer 68

Complex life cycle that involves snails and can invade through the skin of humans wading in water where they will invade in the liver to reproduce

Question 69

Katayama Fever

Answer 69

Associated with Schistosoma infection with acute fever, cough and LAD that is self-limiting

Question 70

How is Schistosomiasis diagnosed?

Answer 70

– Characteristic ova in feces or urine | – Rectal biopsy crush preparation

Question 71

What is the treatment for Schistosomiasis?

Answer 71

Praziquantel

Question 72

What does S. mansoni ova have as characteristics?

Answer 72

Round with a distinguishing spine

Question 73

Cercarial Dermatitis

Answer 73

* Accidental infection of human swimmers with duck schistosome * Papular dermatitis with intense itching

Question 74

What are some of the associations of Clonorchis (liver fluke) infection?

Answer 74

– Obstructive biliary tract disease | – Associated with cholangiocarcinoma

Question 75

How is Clonorchis acquired?

Answer 75

* Complex life cycle involving snail | * Acquired by ingestion of metacercariae- infested fish

Question 76

What are the signs of Paragonimus westermani (lung fluke) infection?

Answer 76

Cough, hemoptysis, chronic pneumonia, lung abscess, pleural empyema

Question 77

How is Paragonimus acquired?

Answer 77

* Complex life cycle involving snail | * Acquired by ingestion of metecercaraial- infested crayfish/crab

Question 78

How is Paragonimus diagnosed?

Answer 78

Ova seen in the sputum or in the stool