2. Which protozoan parasite do you think was causing this patient's illness? Explain. Coccidia are single celled organisms that infect the intestine. Coccidia are single celled organisms that infect the intestine. Coccidia infection causes a watery diarrhea which is sometimes bloody and can even be a life-threatening problem to an especially young or small pet. Coccidia infection causes a watery diarrhea which is sometimes bloody and can even be a life-threatening problem to an especially young or small pet.

3. most common infections are with coccidia of the genus Isospora (pictured here).

4. Which other procedures may be used to diagnosis this infection ? A routine fecal test is a good idea for any new puppy or kitten whether there are signs of diarrhea or not as youngsters are commonly parasitized. This sort of test is also a good idea for any patient with diarrhea. The above illustration demonstrates coccidia oocysts seen under the microscope in a fecal sample. Coccidia are microscopic and a test such as this is necessary to rule them in. A routine fecal test is a good idea for any new puppy or kitten whether there are signs of diarrhea or not as youngsters are commonly parasitized. This sort of test is also a good idea for any patient with diarrhea. The above illustration demonstrates coccidia oocysts seen under the microscope in a fecal sample. Coccidia are microscopic and a test such as this is necessary to rule them in. It should be noted that small numbers of coccidia can be hard to detect so just because a fecal sample tests negative, this does not mean that the pet is not infected. Sometimes several fecal tests are performed, especially in a young pet with a refractory diarrhea; parasites may not be evident until later in the course of the condition. It should be noted that small numbers of coccidia can be hard to detect so just because a fecal sample tests negative, this does not mean that the pet is not infected. Sometimes several fecal tests are performed, especially in a young pet with a refractory diarrhea; parasites may not be evident until later in the course of the condition.

5. Which factor in the child's history might put her at risk for such infections? Which other parasitic infections are associated with this factor? Oocysts (pronounced o'o-sists), are passed in stool. In the outside world, the oocysts begin to mature or “sporulate.” After they have adequately matured, they become infective to any host (dog or cat) that accidentally swallows them. Oocysts (pronounced o'o-sists), are passed in stool. In the outside world, the oocysts begin to mature or “sporulate.” After they have adequately matured, they become infective to any host (dog or cat) that accidentally swallows them. To be more precise, coccidia come from fecal-contaminated ground. They are swallowed when a pet grooms/licks the dirt off itself. In some cases, sporulated oocysts are swallowed by mice and the host is infected when it eats the mouse. Coccidia infection is especially common in young animals housed in groups (in shelters, rescue areas, kennels, etc.) This is a common parasite and is not necessarily a sign of poor husbandry. To be more precise, coccidia come from fecal-contaminated ground. They are swallowed when a pet grooms/licks the dirt off itself. In some cases, sporulated oocysts are swallowed by mice and the host is infected when it eats the mouse. Coccidia infection is especially common in young animals housed in groups (in shelters, rescue areas, kennels, etc.) This is a common parasite and is not necessarily a sign of poor husbandry.

6. Why would this patient's course of illness probably be less severe than the same infection in an AIDS patient? Should this child be treated? How? Should this child be treated? How?

7. We do not have any medicine that will kill coccidia; only the patient’s immune system can do that. But we can give medicines called “coccidiostats” which can inhibit coccidial reproduction. Once the numbers stop expanding, it is easier for the patient’s immune system to “catch up” and wipe the infection out. This also means, though, that the time it takes to clear the infection depends on how many coccidia organisms there are to start with and how strong the patient’s immune system is. A typical treatment course lasts about a week or two but it is important to realize that the medication should be given until the diarrhea resolves plus an extra couple of days. Medication should be given for at least five days total. Sometimes courses as long as a month are needed. We do not have any medicine that will kill coccidia; only the patient’s immune system can do that. But we can give medicines called “coccidiostats” which can inhibit coccidial reproduction. Once the numbers stop expanding, it is easier for the patient’s immune system to “catch up” and wipe the infection out. This also means, though, that the time it takes to clear the infection depends on how many coccidia organisms there are to start with and how strong the patient’s immune system is. A typical treatment course lasts about a week or two but it is important to realize that the medication should be given until the diarrhea resolves plus an extra couple of days. Medication should be given for at least five days total. Sometimes courses as long as a month are needed.

8. Describe the life cycle of this parasite. ingestion of sporulated oocysts containing sporozoites. Sporozoites penetrate intestinal cells, feed, grow and eventually go through a-sexual reproduction called schizogony. The end result of this division is the production of merozoites which rupture from the infected cell and enter new cells. At some point, some merozoites begin the sexual phase of the life cycle, being micro and macro-gametes. Fertilization occurs and a zygote is produced within the host cells. The zygote is called a oocyst and eventually passes out of the intestine with the feces in an unsporulated form (above, right). In all instances, the number of asexual cycles is pre-determined. Pathogenesis is related to intestinal cell distruction. ingestion of sporulated oocysts containing sporozoites. Sporozoites penetrate intestinal cells, feed, grow and eventually go through a-sexual reproduction called schizogony. The end result of this division is the production of merozoites which rupture from the infected cell and enter new cells. At some point, some merozoites begin the sexual phase of the life cycle, being micro and macro-gametes. Fertilization occurs and a zygote is produced within the host cells. The zygote is called a oocyst and eventually passes out of the intestine with the feces in an unsporulated form (above, right). In all instances, the number of asexual cycles is pre-determined. Pathogenesis is related to intestinal cell distruction.

9. There are two other coccidian parasites that are modified acid-fast. Name these parasites, and explain how you would distinguish them from the parasite infecting

10. The most common genera are Eimeria and Isospora.

12. Cryptosporidium spp - This parasite is similar to most coccidia except that the organism is not considered to be host specific and is located in parasitophorous vacuoles just under the surface membrane of host cells or within its striated border rather than within host cells. Additionally, the oocysts are small in size (4-6 micrometers), and sporulation can occur internally resulting in sporulated oocysts being passed in the feces, Some species are thought to be host specific while others are easily transmitted among diffrent species of animals. Transmission is by the fecal-oral route Cryptosporidium spp - This parasite is similar to most coccidia except that the organism is not considered to be host specific and is located in parasitophorous vacuoles just under the surface membrane of host cells or within its striated border rather than within host cells. Additionally, the oocysts are small in size (4-6 micrometers), and sporulation can occur internally resulting in sporulated oocysts being passed in the feces, Some species are thought to be host specific while others are easily transmitted among diffrent species of animals. Transmission is by the fecal-oral route