Parasitic Infections- Exam 2 Flashcards
______ is primarily Entamoeba histolytica. What is the mode of transmission? what is the host?
Amebiasis
fecal-oral route but can occur through sexual contact
humans
In toxoplasmosis, IgM is ____, IgG is _____
acute
chronic
____ is found worldwide, mainly in subtropical/tropical areas due to crowding, poor sanitation, poor nutrition
Amebiasis
What is the typical incubation of amebiasis?
2-4 weeks
gradual onset diarrhea, abd pain, bloating, usually afebrile
PE - abd distension, abd tenderness, hyperperistalsis, hepatomegaly
Microscopic hematochezia is commonly found
Periods of remission-recurrence may last for weeks
What am I?
mild/moderate amebiasis
colitis, dysentery with 10-20 bloody/watery stools per day
High fevers, prostration, vomiting, abd pain
PE - abd distension, abd tenderness, hepatomegaly, hypotension
Hematochezia is common
What am I?
moderate/severe amebiasis
______ is MC in young children, pregnant pts, malnourished, pts on steroids
moderate/severe amebiasis
What are the acute complications associated with amebiasis?
necrotizing colitis, intestinal perforation, mucosal sloughing, hemorrhage, death
Mortality rates > 40%
What are the chronic complications associated with amebiasis?
chronic diarrhea with weight loss, bowel ulcerations, amebic appendicitis
_____ is the MC extraintestinal manifestation of amebiasis. What are some s/s? More common in men or women?
Amebic Liver Abscess
Abdominal pain, fever, enlarged/tender liver, anorexia, wt loss
MC seen in men; can occur without any hx of colitis
Can rupture–often fatal if rupture occurs
How do you dx intestinal amebiasis? What test should you order?
Stool Microscopy/O&P - E. histolytica
trophozoites and cysts
Stool antigen test
Stool PCR for parasitic DNA/RNA
How do you dx hepatic amebiasis? What test should you order?
*Anti-amebic antibodies - serological
test; almost always +
*Stool O&P or antigen - often negative
*Imaging - US or CT of liver
What is the treatment for amebiasis?
Initial - metronidazole (10 days) or tinidazole (3 days)
Eliminates E. histolytica trophozoites
Followed by - paromomycin x 7 days
PO aminoglycoside
Eliminates E. histolytica cysts
May be only tx if pt has no s/s
How do you prevent amebiasis?
Avoid fruits, vegetables, and
water in endemic areas
Especially in Central/South America, India,
Indonesia, tropical and
sub-Saharan Africa
Handwashing
Boiled water
Thoroughly cooked food
_____ is caused by Giardia lamblia. Where is it commonly found?
Giardiasis
found worldwide, especially in areas with poor sanitation
______ is the MC intestinal protozoal pathogen in US
Giardiasis
What are some risk factors for Giardiasis?
Travelers to Giardia-endemic areas
-Tropical regions with poor sanitation
Swallowing contaminated water during
wilderness or recreation travel
Men who have sex with men
Immunocompromised
______ their cysts can survive weeks-months in the environment
Can survive in chlorinated water
May see outbreaks in households, daycares
Hosts - humans, dogs, cats, numerous wild animals
What am I?
What is the incubation period?
Giardiasis
1-3 weeks
Giardiasis is not discernible in ___ of patients. Asymptomatic cyst passers are ___ of patients
50%- No discernible infection
10%- Asymptomatic cyst passers
Profuse watery diarrhea, weight loss, dehydration
Usually afebrile with no vomiting
May require hospitalization due to dehydration
What am I?
acute diarrheal syndrome of giardiasis
Diarrhea - daily or in remitting-recurring cycles that may alternate with constipation
Greasy or frothy, foul-smelling stools; no blood, mucus, or pus
-May see malabsorption - decreased protein, fats, vitamins
Abdominal cramps, bloating, flatulence, nausea, malaise; no fever or vomiting
Symptoms can persist weeks to months
What am I?
Chronic Diarrheal Syndrome related to giardiasis
What is the correct procedure to dx giardiasis? What will the stool microscopy O&P show?
Stool Microscopy/O&P
—-Positive for cysts and trophozoites
—–No blood or leukocytes
*Stool antigen assay for Giardia
*Stool PCR for Giardia
What is the treatment for giardiasis? For patients 1-3yrs? for less than 12 months?
tinidazole 2 g PO x 1 dose
nitazoxanide 500 mg PO BID x 3 days
metronidazole 500 mg PO BID x 5-7 days
_____ interferes with normal reproduction cycle of Cryptosporidium and Giardia
Nitazoxanide (Alinia)
SE of ____ are usually minimal - GI upset, headache, dizziness, discolored (bright yellow) urine
What are the SE of Nitazoxanide (Alinia)?
_____ have a fecal- oral route of transmission, worldwide distribution and are commonly found in HIV+ pts and swimming pool outbreaks
Cryptosporidiosis
Can be in HIV+ and immunocompetent pts as well, found in 65-97% of surface waters, often see outbreaks in daycares and households. What am I? What is a clinical pearl associated with this protozoa?
Cryptosporidiosis
**swimming pool outbreaks
Fecally contaminated food, water, or hands
Cysts can survive years in the environment
Can survive in chlorinated water
Often see outbreaks in communities, households, daycares - highly infectious
Hosts - humans, numerous animals
What am I?
How long is the typical incubation?
Cryptosporidiosis
1-14 days
5-10 days of diarrhea; other s/s for up to 2 weeks
Watery, nonbloody diarrhea
N/V, abdominal pain and cramping
Low-grade fever is possible
May have milder or asymptomatic course
What am I?
acute Cryptosporidiosis
typically have chronic presentation
Chronic diarrhea - frequent, foul-smelling stools
Malabsorption and weight loss
Extraintestinal disease
Pulmonary infiltrates and dyspnea
Biliary tract infection and sclerosing cholangitis
What am I?
HIV/AIDS pt with Cryptosporidiosis
How do you dx Cryptosporidiosis? What will stool O&P show?
Stool microscopy/O&P with acid-fast stain
—-No blood or leukocytes
**Stool antigen assay for Cryptosporidium
**Stool PCR testing
**What is the treatment for acute Cryptosporidiosis?
**Acute form is self-limiting; may use supportive tx
What is the treatment for Cryptosporidiosis for immunosuppressed patients or persistent cases?
**Nitazoxanide or paromomycin
Consider adding azithromycin if severe symptoms or refractory to tx
______ is associated with Cyclospora cayetanensis
Cyclosporiasis
Fecal-oral route
Ingestion of oocyst form of parasite
Worldwide distribution
Endemic to Haiti, Peru, Nepal
Often linked to foodborne outbreaks
in US from imported produce
What am I?
Cyclosporiasis
**Cyclosporiasis what is the clinical pearl? What is the typical incubation?
MC in imported **fresh produce
2-14 days
May see a flu-like prodrome
Watery diarrhea, nausea and abdominal cramping
Fatigue, malaise, anorexia
Fever present in 25%
Symptoms usually present for 2+ weeks
May remit and relapse for months
What am I?
symptomatic cyclosporiasis
What would immunocompromised patients who have contracted cyclosporiasis present like?
May see a flu-like prodrome
Watery diarrhea, nausea and abdominal cramping
Fatigue, malaise, anorexia
Fever present in 25%
Symptoms usually present for 2+ weeks
May remit and relapse for months
More severe, prolonged symptoms
Chronic, fulminant watery diarrhea and weight loss
How do you dx Cyclosporiasis?
**Stool microscopy/O&P with acid-fast stain
Colonoscopy with biopsy
What is the treatment for Cyclosporiasis? include both first and second line
First line: **TMP-SMX (Bactrim) 160/800 BID x 10 days
Long-term, 3x/wk prophylactic treatment can reduce recurrence in AIDS pts
Second-line options (also for 7 days)
Ciprofloxacin (Cipro) - may not be as effective as TMP-SMX
Nitazoxanide (Alina) - not as well studied, seems effective
May be good for pts with sulfa allergy
_____ is caused by Trichomonas vaginalis
Trichomoniasis
_____ is sexually transmitted, worldwide and very common cause of GU infections. What is the most common pt demographic?
Trichomoniasis
Especially common in non-Hispanic
black females
Name all the ways you can get trichomoniasis. What is the typical incubation?
sexually transmitted- MC
contact with moist, contaminated
cloths, toilet seats, specula
mothers to newborn during birth
5-28 days
Frothy, yellow or green nonmalodorous vaginal discharge
Vulvovaginal discomfort, abdominal pain
Dysuria, dyspareunia, pruritus
inflamed vaginal mucosa and cervix with punctate hemorrhages
“Strawberry Cervix”
May have milder or asymptomatic course
Does NOT usually have an odor
What am I?
Trichomoniasis
What is the classic presentation of trichomoniasis in males?
Dysuria
Scant, thin urethral discharge
How do you dx trichomoniasis?
Wet prep of vaginal or urethral secretions
——-Presence of motile, flagellated organisms
**Nucleic acid assay (PCR)
What will a wet prep of trichomoniasis look like?
Presence of motile, flagellated organisms
What is the treatment for trichomoniasis?
**Tinidazole or Secnidazole - 2 g PO x 1 dose
Alternative - metronidazole 500 mg PO BID x 1 week
Refractory - tinidazole 2 g PO QD x 14 d, +/- vaginal boric acid or paromomycin
Must also treat all sexual partners!
____ is fecal-oral, ingestion of cysts in undercooked meat, transplacental, or from infected organ/blood donor.
Toxoplasmosis
_____ is caused by Toxoplasma gondii
Toxoplasmosis
**_____ is worldwide and one of the leading causes of deaths from foodborne illness in the US
Toxoplasmosis
Toxoplasmosis is more concerning in ____ and _____ pts
pregnant or immunosuppressed pts
Name some ways you can contract toxoplasmosis. What is the typical incubation?
Fecal-Oral Transmission- CATS!!!
Ingestion of infected meat
Transplacental infection
Infected donor transmission
1-2 weeks
mono-like - fever, malaise, sore
throat, HA, myalgias, LAD, HSM
Rare - hepatitis, meningoencephalitis,
polymyositis, retinochoroiditis
What am I?
What percentage is asymptomatic?
primary toxoplasmosis infection of a normal person
80-90% will have no symptoms