Ch. 18 - Parasites (Protozoans) Flashcards Preview

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Flashcards in Ch. 18 - Parasites (Protozoans) Deck (9):


"Bad air"

1 million children die each year, one child every 30 seconds

Plasmodium species:
P. Malariae
P. Falciparum - most serious

Transmitted via female mosquito - human blood needed to produce chemical component in eggs

Two hosts: mosquito (definitive host) and human (intermediate host)

RBC rupture - release parasites and toxins
Symptoms occurs when RBC lysed --> fever, headache, nausea, vomiting

Death due to RBC destruction (anemia), clots from RBC fragments

Breed in standing water

Treatment: quinine (tree extract), cloroquinone, mefloquine



Universal parasite --> common in AIDS pts --> cause sever disease

One of the most common infectious diseases

Toxoplasma Gondi

Symptoms: high fever, swollen spleen, liver, and lymph nodes

Transmission: soil --> animals (cats, cows)--> humans (pets, contaminated beef)

Diagnosis: identification in blood, bodily fluids

Treatment: Sulfonamides

Congenial risk (TORCH) - cross the placenta, retina infection


Leishmaniasis - Visceral Disease (kala-azar)

Sandfly vector

Blood - "black fever"

High fever, swollen speed and liver

90% fatal -- infection of WBC

Veterans in Iraq/Afghanistan


Leishmaniasis - Cutaneous Disease

Vector - sand fly

Skin sores that ulcerate

"Baghdad boil"


Trachoma as vaginalis

Transmitted by sexual contact

Women - STD - vaginitis
Men - usually asymptomatic

Symptoms: dysuria (painful urination), pruritis (itching), yellow and frothy discharge

Treatment - to pt and partner--> to prevent transmission or reinfection



Cryptosporidium parvum
-highly infectious protozoan

Transmission: fecal oral route (contaminated water)

Healthy - limited diarrhea
Immunocompromised - opportunistic (AIDS); profuse diarrhea and dehydration

Treatment: fluid replacement


Pinworm Disease

Caused by roundworms, live in intestines

Symptoms: diarrhea, itching in anal region

Diagnosis: Tape to wooden stick --> surface of tape to anal region --> tape onto slide --> slide examined microscopically for pinworm eggs



Babesiosa microti

Top 6 microbes causing emerging infections - only parasite on the list
Emerging infection in NE USA

Malaria-like disease --> parasites invade RBC --> anemia, headache, occasionally meningitis

Transmission - ticks


Parasites - general

Protozoans - organisms that must live in/on a different species to get their nourishment


Complicated life cycle

Insect vector

No cell wall (unique!)