Protozoa

“first animal”- one-celled eukaryotes that inhabit water

and soil(Page 416)

Amoebiasis(Amoebic Dysentery)

Readings question #1:How do the cysts of the protozoan amoeba Entamoeba histolytica cause disease in the human?

• Diagnosis: feces serological tests

Malaria

Page 417Readings question #2:

How does the Anopheles mosquito transport the microorganism that causes malaria? How is the microorganism transmitted to the human host?

Plasmodium Protozoa

• Readings question #3:Describe the movement of the Plasmodium protozoa once it has entered the human host and the symptoms that occur. (Also known as the “Life Cycle of Malaria”?)

Uncomplicated Malaria

• attack lasts 6-10 hours

• Stages: cold stage (shivering)hot stage (fever, headaches, vomiting, seizures in young

children)sweating stage (return to normal temperature, tiredness)

Severe Malaria

• always a medical emergency• manifestations:– cerebral malaria– severe anemia– hemoglobinuria– pulmonary edema– thrombocytopenia– cardiovascular collapse

Malaria Relapses

• may occur months or even years without symptoms

• due to dormant liver stage parasites that may reactivate

• mosquito control in the U.S. has decreased the number of cases of malaria

• treatment: quinine• serious threat in parts of the world where

mosquitoes breed uncontrollably

Toxoplasmosis

• caused by single-celled protozoan: Toxoplasma gondii• healthy people who become infected do not have

symptomsReadings question #4:

How can humans contract toxoplasmosis? What is the most common form of transmission?

Pregnant Women

• if infected BEFORE becoming pregnant, the unborn child is protected because the mother has developed immunity

• if infected during pregnancy, can pass the infection to the unborn child– the earlier the transmission, the more severe the

result for the unborn child (miscarriage, stillborn, vision loss, mental disability, seizures)

Life Cycle of Toxoplasma gondii

• Page 418 Figure 28-5

Readings question #5:

What are the symptoms of toxoplasmosis?