Cryptosporidium

Question 1

What are the three types of emerging diseases?

Answer 1

not occurred in humans before, previously occurred but only in small numbers, and occurred throughout history but recently recognised as a distinct disease

Question 2

What is a re-emerging disease?

Answer 2

a disease that was once a major health problem, then declined dramatically, and again is becoming a major health issue

Question 3

To which phylum does Cryptosporidium belong?

Answer 3

Apicomplexa (all parasites in this phylum are called coccidia)

Question 4

Where does Cryptosporidium develop in the body?

Answer 4

In the GI tract

Question 5

Why is Cryptosporidium an unusual Apicomplexan?

Answer 5

it is phylogenetically very distant to other species in the phylum

Question 6

What is the infective stage?

Answer 6

oocysts

Question 7

Which are the two most important organelles in the apical complex?

Answer 7

micronemes and rhoptry

Question 8

How is the oocyst unique?

Answer 8

the oocyst wall has a suture at the end that dissolves during excystation. this allows the sporozoites to colonise the villi of the small intestine

Question 9

How are oocysts transmitted?

Answer 9

Through the fecal-oral route

Question 10

Is C. parvum species specific?

Answer 10

no

Question 11

What is the most common clinical symptom?

Answer 11

diarrhea

Question 12

What are some other clinical symptoms?

Answer 12

abdominal pain, nausea, fever, fatigue, breathing

Question 13

Which group of individuals shows less signs of symptoms?

Answer 13

immunodeficient individuals

Question 14

Which group of individuals has the highest mortality rate?

Answer 14

persons with AIDS

Question 15

What effect do the metabolites secreted by Cryptosporidium have on the body?

Answer 15

• inhibition of glucose-stimulation affecting Na absorption

- increased production of mucosal prostaglandin which can inhibit NaCl absorption (leading to diarrhea)

Question 16

What affect does the immune system reacting to Cryptosporidium have on the body?

Answer 16

• leukocytes can produce high levels of prostaglandins

- alterations in intestinal permeability via increased secretions of cytokines (ex. IFN-gamma and TGF)

Question 17

How can one contract the parasite?

Answer 17

from animals, manure used as fertilizer, person-to-person contact, waterborne, foodborne, airborne

Question 18

Who is at risk?

Answer 18

veterinarians, farmers, medical personel, day-care workers, immunodeficient people, children, owning pets, family, sexual activities (anaallll), non-filtered water, etc

Question 19

What is the percent efficiency of using water samples to test for the presence of Cryptosporidium?

Answer 19

6.3%

Question 20

What are some new detection methods and what are the disadvantages?

Answer 20

ELISA and PCR

both are expensive, cannot distinguish between viable and non-viable cells, and they are not species-specific

Question 21

What is apparently the best water treatment method?

Answer 21

sand filtered water

Question 22

What is the percent of surface water that was tested positive in Canada and in Quebec?

Answer 22

4.5% in Canada, 12% in Quebec only

Question 23

What is the issue with chemotherapy and this disease?

Answer 23

because chemo destroys the host immune system, they cannot fight the infection on their own and must take drugs

Question 24

Which drugs have been used successfully to treat cryptosporidiosis?

Answer 24

spiramycin, azithromycin, paromomycin

Question 25

How invasive is the parasite?

Answer 25

not very invasive. only resides on the apical surface of intestinal epithelium. still elicits innate and acquired immune responses and causes inflammation