Protozoan Diseases

unicellular eukaryotic

Protozoans are multicellular/unicellular eukaryotic/prokaryotic organisms

Malaria, African sleeping sickness, and leishmaniasis

What are some diseases protozoans are responsible for?

Bloodstream (humoral) and intracellular (cell-mediated)

Types of immune responses

Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense

What causes African Trypanosomiasis?

Tse tse fly

What typically transmit African trypanosomiasis?

1. Bite infected human

2. Replication in bug

3. Bite new human

What is the life cycle of the African typanosomiasis?

life cycle

Almost all parasites have a...

West African and East African (worse)

What are the two types of African trypanosomiasis and which is worse?

Hemolymphatic stage and meningoencephalitis stage

What are the two stages of African trypanosomiasis?

Severe headache, somnolence, coma, and death

What symptoms occur if African trypanosomiasis if the disease occurs?

Bite site; East African

Where does a chancre occur with African sleeping sickness and what type is more common with?

death

If African trypanosomiasis is not treated early ____________ can occur

East African early, West African later

Which type of African trypanosomiasis can be treated early and which can be treated later?

Fexinidazole

What drug cures all stages of African trypanosomiasis in 10 days?

Chagas disease

American trypanosomiasis is referred to as...

Trypanosoma cruzi

What causes American trypanosomiasis?

protozoan parasite

Trypanosoma cruzi is a...

Heart disease

What does American trypanosomiasis cause in primarily South America?

Acute and chronic

What are the disease stages of American trypanosomiasis (Chaga's disease)?

asymptomatic

Most people in the early stages (70%) of American trypanosomiasis are...

Romaña (eye) and chagoma (skin)

Common signs with acute American trypanosomiasis

Local lymphadenopathy, fever, malaise, headache, and hepatosplenomegaly

Common symptoms with acute American trypanosomiasis

parasites in blood

American trypanosomiasis is usually diagnosed in the acute stage via...

Cardiac (heart attack) and smooth muscle (achalasia of esophagus)

When American trypanosomiasis reaches the chronic stage, what tissues are affected (and what occurs)?

Serologic tests

How is chronic American trypanosomiasis diagnosed?

indeterminate; determinate

In the chronic phase, American trypanosomiasis typically has a __________________ and ________________ form

Indeterminate form

In which chronic stage form is treatment with an antiparasitic drug more successful?

Bite from infected female anopheles mosquito

How is one infected with malaria?

RBCs

What does malaria infect?

young children; single severe episode or anemia from multiple infections

Most deaths due to malaria are ________________ due to...

Patient has fever and appropriate travel history

When MUST you consider malaria?

fever in tropics

Malaria is the most common cause of...

Babesia microti

What causes Babesiosis?

intraerythocytic parasite

Babesia microti is a...

Rings with basophilic stippling (under microscope)

How is Babesia microti distinguished from malaria?

<1%

What % of RBCs are infected with babesiosis?

Cattle and dogs

What serve as the reservoir for Babesia microti?

Tick bite (Ixodes scapularis) or blood transfusion

How is babesiosis transmitted?

mild

Most people that have babesiosis have a ____________ illness

20 species of Leishmania

What causes leishmaniasis?

Sand flies

What transmits leishmaniasis?

Cutaneous, visceral, and mucocutaneous

What are the 3 types of leishmaniasis?

Single or multiple chronic painless, moist ulcers or dry nodules that appear 2 weeks to several months after infection

What symptoms are common with cutaneous leishmaniasis?

months to years; scarring

Ulcers caused by cutaneous leishmaniasis normally spontaneously heal in _________________ and cause _______________

If on hands or face and New world type

When should cutaneous leishmaniasis be treated?

Prevent mucocutaneous leishmaniasis

Why should hand, face, or New world cutaneous leishmaniasis be treated?

destructive nasopharyngeal lesion

Mucocutaneous leishmaniasis causes...

Visceral leishmaniasis (kala azar)

Most deadly form of leishmaniasis (90% fatality rate without treatment) that causes a "black fever" hyperpigmentation of the skin, irregular fever, hepatosplenomegaly pancytopenia, and wasting

Toxoplasma gondii

What causes toxoplasmosis?

Cats

What serve as the reservoir for Toxoplasma gondii?

Ingestion of cysts in raw/undercooked meat, oocysts in food/water contaminated by cat, transplacental, and blood transfusion or organ transplant

When can humans develop a Toxoplasma gondii infection?

20-30%

How many people in the U.S. are seropositive for Toxoplasmosis gondii?

Primary infection, congenital infection, retinochoroiditis, and reactivated disease in immunocompromised patients

4 syndromes of toxoplasmosis

nonimmune

For a congenital toxoplasmosis infection to occur, the mother must be _____________. The infection can also present as symptomatic or asymptomatic

asymptomatic

Most acute toxoplasmosis infections are...

ID of parasites and serum AB testing of IgG and IgM

How is primary toxoplasmosis diagnosed?

No exposure

Interpret the following results and what toxoplasmosis infection (if any) is occurring: IgG/IgM negative

Acute infection

Interpret the following results and what toxoplasmosis infection (if any) is occurring: IgM positive

Chronic infection or previous exposure

Interpret the following results and what toxoplasmosis infection (if any) is occurring: IgG positive

spontaneously

Most people with a primary toxoplasmosis infection recover...

tachyzoites

Treatment of toxoplasmosis is only effective against _____________, so it does not eradicate infection

As pregnancy progresses, risk of fetal infection increases, but severe fatal disease decreases

What is the pattern regarding chance of infection and symptoms severity with a congenital toxoplasmosis infection?

Spontaneous abortion, stillbirth, and sever neurologic manifestations

What can a congenital toxoplasmosis infection cause?

Weeks to years later

When does the retinochoroiditis syndrome of toxoplasmosis appear following a congenital infection?

AIDS, cancer, and those on immunosuppressive drugs

In what patients does a reactivated toxoplasmosis infection occur?

Encephalitis, retinochoroiditis, pneumonitis, and myocarditis

What does a reactivated toxoplasmosis infection cause?

IgG + (and IgM -) and brain CT and/or MRI

How is a reactivated toxoplasmosis infection diagnosed?

Avoiding undercooked meat and contact with contaminated cat feces and chemoprophylaxis for immunocompromised

How is a toxoplasmosis infection prevented?

Humans

What serve as the host of Entamoeba histolytica?

ingestion of cysts from fecally contaminated food/water or human to human

How is Entamoeba histolytic transmitted?

Men who have sex with men

Entamoeba histolytica spreads human to human especially in what population?

Amebiasis

What does Entamoeba histolytica cause?

Intestinal and extraintestinal

Two types of amoebiasis

Control of food/water supply and proper sanitation and personal hygiene

How is a amebiasis infection prevented?

1. Ingested cysts to intestine

2. Trophozoites hatch

3. Invade mucosa

4. Cause necrosis

Life cycle of Entamoeba histolytica

Perforation, abscess, and peritonitis causing pain, obstruction, or hemorrhage

Common symptoms of amebiasis

Ameboma

Local granuloma caused by Entamoeba histolytica

Liver; blood vessels from intestines travel via portal system to liver

Where do abscesses caused by Entamoeba histolytica typically occur? Why does this make sense?

asymptomatic

Intestinal amebiasis is often...

Gradual onset of abdominal pain and diarrhea, distention, hyperperistalsis, and cyclic nature

Signs and symptoms of mild intestinal amebiasis

Pregnant women, young children, and patients on corticosteroids

In what patients is severe intestinal amebiasis most common?

High fevers, prostration, and vomiting (can lead to necrotizing colitis or perforation)

Symptoms of severe intestinal amebiasis

Never treat with steroids until amebiasis is ruled out

What is important to remember when treating a presumed inflammatory bowel disease?

Liver abscess in right lobe

Most common symptom of extraintestinal amebiasis

lungs, brain, and genitalia

Rarely, abscesses for extraintestinal amebiasis can occur in the...

1. ID of cysts or trophozoites in 3 stool samples

2. Serum Ab tests

3. Mild elevation in WBCs

4. Ulcers in colonoscopy

5. ID of organisms or + antigen test on abscess aspirate

How is amebiasis diagnosed?

If no response to tinidazole or metronidazole and luminal amebicide occurs in 3 days

When is a hepatic abscess caused by amebiasis drained?

Cryprosporidium Sp.

What causes coccidiosis and microsporidiosis?

Oocyts and spores

What serve as the infectious agents for Cryprosproidium Sp?

ingestion of contaminated water in lakes or swimming pools

Coccidiosis and microsporidiosis typically cause outbreaks of diarrhea in daycare and households due to...

Prolonged diarrhea

What does Cryprosporidium Sp. cause in immunocompromised patients?

Ingestion of fecal sporocysts in undercooked beef or pork

How does one develop sarcocystosis?

Myalgias, fever, bronchospasm, and pruritic rash

Signs and symptoms of sarcocystosis

Elevated eosinophils and creatine kinase and ID of organism in stool or muscle biopsy

How is sarcocystosis diagnosed?

Giardia lamblia

What causes giardiasis?

US and Europe

Giardia is the most common protozoal pathogen in the...

Travelers to endemic areas and swallowing of contaminated water with recreational or wilderness travel

How does Giardia lamblia typically spread?

10

How many Giardia lamblia cysts are needed to cause an active infection?

Trichomonas vaginalis

What causes trichomoniasis?

flagellated protozoan parasite

Trichomonas vaginalis is a...