Ch. 18 - Parasites (Protozoans)

Question 1

Malaria

Answer 1

“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

Question 2

Toxoplasmosis

Answer 2

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

Question 3

Leishmaniasis - Visceral Disease (kala-azar)

Answer 3

Sandfly vector

Blood - “black fever”

High fever, swollen speed and liver

90% fatal – infection of WBC

Veterans in Iraq/Afghanistan

Question 4

Leishmaniasis - Cutaneous Disease

Answer 4

Vector - sand fly

Skin sores that ulcerate

“Baghdad boil”

Question 5

Trachoma as vaginalis

Answer 5

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

Question 6

Cryptosporidiosis

Answer 6

Cryptosporidium parvum
-highly infectious protozoan

Transmission: fecal oral route (contaminated water)

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

Treatment: fluid replacement

Question 7

Pinworm Disease

Answer 7

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

Question 8

Babesiosis

Answer 8

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

Question 9

Parasites - general

Answer 9

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

Eukaryotes

Complicated life cycle

Insect vector

No cell wall (unique!)