Cryptosporidiosis

Question 1

Pathogenic significance unclear unCl 1955‐Slavin described infecCon in turkeys

Answer 1

Cryptosporidium

Question 2

Apicomplexan parasite described in 1907 by Tyzzer in gastric gland of mice (hidden sporocyst)

Answer 2

Cryptosporidium

Question 3

Low mortality but severe diarrhea

Answer 3

cryptosporidiosis

Question 4

Releases sporozoites and can be found in the intestine

Answer 4

oocysts

Question 5

attached to the epithelial cells

Answer 5

sporozoites

Question 6

undergo ASEXUAL reproduction by merogony (endopolygeny)

Answer 6

Tropozoites

Question 7

What are the two types of meronts?

Answer 7

Type 1 meron

Type 2 meron

Question 8

form 8
merozoites released from
the PV when mature.

Answer 8

Type 1 meront

Question 9

form 8
merozoites released from
the PV when mature.

Answer 9

Type 2 meront

Question 10

form 8
merozoites released from
the PV when mature.

Answer 10

Monoxenous life cycle

Question 11

T or F: Zygote undergo asexual development
producing a sporulated oocyst with 4
sporozoites.

Answer 11

True

Question 12

Toxoplasma gondii

invasion depends only on _________

Answer 12

parasite actin

Question 13

Incubation period: crypto

Answer 13

2-4 days

Question 14

Clinical symptoms

Answer 14

Watery and profuse diarrhea, abdominal cramps, nausea,
vomiCng, weight loss and low‐grade fever.
• Self‐limited disease in immuno‐competent individuals
• Prolonged duraCon in immuno‐compromised host.

Question 15

Diagnosis

Answer 15

Detection of endogenous developmental stages: Most stages are basophilic and stain well with
hematoxylin and eosin or giemsa stains.

Question 16

What makes it different from other apicomplexan parasites?

Answer 16

It lacks a plasCd
• It has a highly simplified mitochondrion
which does no longer perform oxidaCve
phosphorylaCon
• It has lost many of its biosyntheCc enzyme
genes and depends almost completely of
host cell derived nutrients

Question 17

Cryprosporidium is HIGHLY resistant. T or F? Why? or why not?

Answer 17

True
Two possible explanaCons for the drug resistance:
1) Drugs do not reach the parasite because it lives in a specialized
compartment
2) The drugs used against other Apicomplexa are metabolically
inappropriate

Question 18

Prevention

Answer 18

Hygiene/disinfecCon‐prevenCon of oocyst transmission‐difficult.
Oocyst very stable in aqueous soluCon; 3 months at 20oC and 1
year at 46oC
• InfecCvity lost upon heaCng (65oC, 30 min) or desiccated for 4h
or snap freezing

Question 19

Chemotherapy

Answer 19

Parasire is highly resistant to it

Question 20

Transmission

Answer 20

Fecal-oral spread of oocysts
Zoonotic transmission
Contaminated food
person-to-person

Question 21

Definitive host

Answer 21

non-specific

mostly terrestrial mammals

Question 22

Intermediate host

Answer 22

NONE

Question 23

Cryptosporidium infects what?

Answer 23

Humans
livestock
pets
almost any domesticated animal

Question 24

Illnesses caused by Cryptosporidium.

Answer 24

Flu-like symptoms 
Diarrhea
may
be life-threatening in
immunosuppressed people

Question 25

Epidemiology

Answer 25

Shed in the feces of infected animals and
humans
• Low infecCve dose: 1‐10 (oo)cysts
• (Oo)cysts immediately infecCous
• Environmental dispersal
• (Oo)cysts are stable, survive long periods in
environment
• Zoono0c

Question 26

Pathogen of cryptosporidiosis

Answer 26

Cryptosporidium parvum

Question 27

Rservoir

Answer 27

Cattle

water

Question 28

Diagnosis

Answer 28

Acid-fast stain

Question 29

Treatment

Answer 29

Oral rehydration