Amebae, GI and Urogenital Sporozoa Flashcards
Describe the general morphology of Amoebae
2 stage life cycle Trophozoite (active motile stage) and Cyst (resistant inactive stage)
replicate by binary fission
What are the 4 clinically relevant amoebae and differentiate if they are free living
- Entamoeba Histolytica
- Entamoeba Polecki
- Naegleria fowleri- free living
- Acanthamoeba sp- free living
Describe Entamoeba Histolytica in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide but higher in tropical and subtropical regions w/ poor sanitation
Cause: ingestion of contaminated food or water, flies and roaches can serve as vectors
Symptoms: burden related
- low=asymptomatic
- high= profuse bloody stools , liver abscess
DX: trophozoites and cyst in stools, PCR and antigen test
Prevention: chlorination of water and education of travelers going to developing countries
Describe Entamoeba Polecki in terms of typical carries, symptoms, how to dx
Carriers: pigs and monkeys
Symptoms: mild transient diarrhea
DX: cyst in stool
Describe Naegleria fowleri in terms of distribution, what causes it, symptoms, how to dx, treatment and prevention
Distribution:
Cause: random bad luck when swimming in warm months of contaminated water
Symptoms: intense headache, fever, blocked nose w/ altered taste/smell, meningoencephalitis, stiff neck, death usually in 4 to 5 days
DX: saline wet prep, ameba in sterile tissues
Treatment: usually ineffective
Prevention: prevent exposure
Describe Acanthamoeba sp in terms of what causes it, symptoms, how to dx, and prevention
Cause: contaminated contact lenses or exposure to contaminated water
Symptoms: ulcerated cornea, and encephaltits in immunocompromised
DX: saline wet prep, ameba trophozoites in sterile tissues
Prevention: prevent exposure
Describe Giardia Duodenalis in terms of distribution, what causes it, symptoms, how to dx, treatment and prevention
Distribution: worldwide in streams and lakes
Cause: fecal oral, consumption of contaminated water, fruits/vegs. Beavers and muskrats are carriers
Symptoms: profuse watery, foul smelling diarrhea (NO blood or pus), malabsorption syndrome if chronic
DX: cyst and trophozoites in stool, need 1 stool x 3 days
Treatment: spontaneous recovery usually, may become chronic in pts w/ diverticula or Ig A def treat those
Prevention: cyst are resistant to chlorination so need filtration or boiling water
Describe Dientamoba fragilis in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide
Cause: possible transmitted with pinworm
Symptoms: asymptomatic to abd discomfort, intermittent diarrhea, anorexia
DX: small trophozoites in stool, need 1 stool x 3 days
Prevention: sanitation
Describe Trichomonas vaginalis in terms of distribution, what causes it, symptoms, how to dx, treatment and prevention
Distribution: worldwide
Cause: sexual intercourse, men are primary carriers
Symptoms:
- women= aymptomatic to vaginitis and PID, may cause adverse pregnancy outcomes
- men= usually asymptomatic but prostatits/urethritis can occur
- neonates= PNA and conjunctivitis
DX: trophozoites in vaginal or urethral discharge
Treatment: both male and female partners are treated w/ metronidazole
Prevention: hygiene, safe sex practices
Describe Neobalantidium. coli in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide where swine is raised
Cause: fecal oral route
Symptoms: abd pain, nauesa, watery, bloody stools
DX: very large trophozoites and cyst in stools
Prevention: hygiene, sanitation
Describe Cystoisospora in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide, increased awareness caused by AIDS
Cause: fecal oral
Symptoms: asymptomatic to severe GI dz that mimic giardiasis
DX: iodine or acid fast staining from stool
Prevention: hygiene, sanitation
Describe Sarocystis in terms of clinical presentation and cause
Intestinal dz= asymptomatic to GI distress from toxin
Muscle dz= fever and muscle pain
cause= eating raw horse meat
Describe Cryptosporidium in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: Worldwide
Cause: drinking contaminated water, fecal oral route
Symptoms: mild self limiting watery diarrhea in healthy pts to chronic profuse (>50 stools per day) in immunocompromised
DX: oocysts that are concentrated in flotation technique
Prevention: sanitation
Describe Cyclospora sp in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide, infects reptiles, birds and mammals
Cause: likely from contaminated water or fruits and vegs
Symptoms: mild abd/GI issues
DX: oocyst by light microscopy
Prevention: resistant to chlorination and not readily id, so must use sanitation, hygiene
