Protozoa Flashcards
Motile form of protozoa
Trophozoite
Form that protozoa takes when exposed to new environments such as temperature changes down the intestinal tract. The protozoa can secrete a protective coat and shrink into this round armored form
Cyst
What are the five intestinal protozoa that cause diarrhea?
- Entamoeba histolytica
- Giardia lamblia
- Cyclosporancayetanesis
- Cryptosporidium
- Isospora belli
Clinical manifestation of entamoeba histolytica
Usually asymptomatic
Can cause bloody diarrhea (10%)
Can cause liver abscess
Who are commonly asymptomatic carriers of entamoeba histolytica
Homosexual men
Most sensitive diagnostic test for entamoeba histolytica
Antigen detection from stool or serum
What is metronidazole (flagyl) used for
Entamoeba histolytica
Giardia lamblia
Trichomonas vaginalis
Bacteroides fragilis
C. Diff
Gardnerella vaginalis
How many us adults are estimated to carry giardia asymptomatically?
5%
Describe giardia stools
Packed with fat
Smell horrible
Greasy, frothy diarrhea
Is there blood in the stool with the giardia infection?
No
Diagnosis of giardia
Examination of stool for cysts or trophozoites
Immunoassay to detect giardia antigens in stool
Protozoa that causes severe protracted diarrhea that is life threatening in people with AIDS, cancer patients, or organ transplant recipients that are receiving immunosuppressive therapy
Cryptosporidium
Treatment for cryptosporidium in immunocompromised patients
No specific treatment for protozoa but goal to restore immunity (ie antiretroviral treatment AIDS pts)
Protozoa that’s been associated with outbreaks from contaminated raspberries
Cyclospora
Protozoa that are acid fast and cause diarrhea and immunocompromised individuals
Isospora and cyclospora
How to treat isospora and cyclospora
Tmp-smp
Protozoa that is sexually transmitted
Trichomonas vaginalis
Test for trichomonas vaginalis
Microscopic examination of vaginal discharge on a wet mount
Symptoms of trichomonas vaginalis
Itching
Burning urination
Vaginal secretion
Treatment for Trachomonas vaginalis
Metronidazole
What are the protozoas that can cause meningitis and be life-threatening? They live in freshwater lakes
Naegleria fowleri
Acanthamoeba
Balamuthia mandrillaris
This protozoa will kill 95% of patients it infects within 1 week
Naegleria fowleri
Responsible for chronic granulomatous, brain infection in immunocompromised patients
Acanthamoeba
Protozoa that causes corneal infection of contact lenses not cleaned properly
Acanthamoeba
Causes acute meningoencephalitis in normal hosts about a week after swimming
Naegleria
The protozoa looks almost identical to bacterial meningitis, but no bacteria in gram stain and may see motile aoemoba
Protozoa causes chronic meningoencephalitis in immunocompromised hosts
Acanthamoeba
This protozoa causes chronic meningoencephalitis in normal and immunocompromised hosts
balamuthia mandrillaris
This protozoa is found causes granulomatous skin lesions
balamuthia mandrillaris
Major protozoan infections in AIDS patients
Cryptosporidium
Isospora
Toxoplasma Gondii
Pneumocystis jiroveci (now a fungi)
Transmission of toxoplasma gondii
Ingestion of cysts from undercooked pork or food contaminated with cat feces
Transplacentally
Who is susceptible to growth of latent toxoplasma Gondii?
AIDS
Immunosuppressive drugs
Most common CNS infection in AIDS patients
Toxoplasma encephalitis
Common clinical manifestations of TOxoplasmosis (if symptomatic)
- fever, swollen lymph nodes, liver and spleen enlargement, pneumo
- meningitis/ brain infection with growing mass in brain
- retinal infection resulting in vision loss
When does congenital toxoplasmosis occur?
Pregnant woman who had never been previously exposed to toxoplasma is infected
Complications of congenital toxoplasmosis
Chorioretinitis and blindness
Seizures
Mental retardation
Microcephaly
Encephalitis
Stillbirth
Dx toxoplasmosis
Ct scan of brain- mass
Retinal inflammation
Serology elevated immunoglobulin
85% of children have had a mild or asymptomatic respiratory illness with this organism by age 4
Pneumocystis jirovechii
Most common opportunistic infection in AIDS patients
Pneumocystis jirovechii pneumonia
What is the prophylactic treatment for PCP in AIDS patients
Tmp-smp
What is the genus of malaria
Plasmodium
Transmission of malaria
Mosquito
What organ does malaria protozoa replicate in?
Liver
Clinical manifestation malaria
Cyclical fevers and anemia
Plasmodium that can continuously reproduce in liver and cause relapsing disease
Plasmodium vivax and ovale
Plasmodium with severe manifestations
Plasmodium falcilarim and knowlesi
Cells plasmodium infects and bursts from
Red blood cells
Dx malaria
Microscopy- direct examination trophozoites in blood
Rapid antigen tests
Tickborne protozoa that is found in red blood cells
Babesiosia
What tick spreads Lyme disease and babesiosis?
Ixodes scapularis
Most common clinical manifestation babesiosis
Asymptomatic or subclinical
Who may have a severe infection with babesiosis?
Aspleenic patients
Transmission leishmaniasis
Bite of sandfly
What type of organism is leishmania?
Protozoa
What arm of the immune system controls the severity of leishmanis infections? What disease does that resemble?
Cell mediated
Resembles leprosy, which is also controlled by cell mediated immunity
What cells does leishmania invade?
Phagocytes
What are the types of leishmania?
Cutaneous leishmania
Muccocutaneous leishmania
Visceral leishmania
Agent for African sleeping sickness
Protozoa trypanosoma brucei
Agent of Chagas disease
Trypanosoma cruzi
Vector for African sleeping sickness
Tsetse fly
Reservoir for Chagas disease
Rodents, opossums, armadillos
Vector Chagas disease
Kidding but, reduviid bug
