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Naegleria fowleri & Acanthamoeba. Ashley Skellie & Karissa Jensen. Naegleria fowleri. Background. Single-celled amoeba 30+ Naegleria species Discovered in Australia Infections are rare. Taxonomy. Geographic Distribution. Worldwide United States Australia Czech Republic - PowerPoint PPT Presentation
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Naegleria fowleri& Acanthamoeba
Ashley Skellie & Karissa Jensen
Naegleria fowleri
BackgroundSingle-celled amoeba30+ Naegleria speciesDiscovered in AustraliaInfections are rare
TaxonomyKingdom ProtistaSubkingdom ProtozoaPhylum SarcomastigophoraSubphylum SacodinaSuperclass RhizopodiaClass AcarpomyxeaOrder SchizopyrenidaFamily VahlkampfiidaeGenus NaegleriaSpecies fowleri
Geographic Distribution
Worldwide United States Australia Czech Republic Great Britain Mexico Czechoslovakia
Prevalent in the summer months
HostsDefinitive
HumansIntermediate
NoneInhabitants of:
SoilWarm, freshwaterGeothermal springsRecreational poolsHeated tap water
Means of InfectionInhaled through the noseCannot spread from human to humanMigrate to the brain via olfactory nervesNeti Pots http://abcnews.go.com/Health/Wellness/fatal-infections-linked-neti-pots/story?id=15170230
http://www.huffingtonpost.com/2011/12/17/brain-eating-amoeba-death_n_1155334.html
MorphologyCyst
8-12 um diameter Single-walled Spherical
Trophozoite 10-15 um diameter Infectious form Reproductive form
Flagellated formReproduce asexually
Binary fission
Life Cycle
Pathogenesis Primary Amoebic
Meningoencephalitis Leads to destruction of brain
tissue Early Symptoms
Headache Fever Nausea Vomiting Stiff neck
Later Symptoms Confusion Lack of attention Loss of balance Seizures Hallucinations
Death within 1 to 12 days
Diagnosis & TreatmentEarly diagnosis is key
Cerebral spinal fluidTissue biopsyAutopsy
Amphotericin BHigh toxicity
MiconazoleHigh mortality rate
Control VectorsAvoid swimming, diving, or jumping into water
when temperatures are high and water levels are low
Hold head above waterHold nose shut; nose plugsAvoid digging up/disrupting sediment while
swimming.
Acanthamoeba
BackgroundPart of same superclass as Naegleria fowleri
Microscopic amoebaRare infection found worldwideMany species infect humansAccidently discovered in 1930
TaxonomyKingdom ProtistaSubkingdom ProtozoaPhylum SarcomastigophoraSubphylum SacodinaSuperclass RhizopodiaClass LoboseaSubclass GymnamoebiaSuborder AcanthopodinaFamily AcanthamoebidaeGenus Acanthamoeba
HostsDefinitive
HumansIntermediate
NoneInhabitants of:
All types of waterHeating, ventilating, and air conditioning systemsDustSoil
MorphologyCyst
Double-walledDormantHighly resistant
Trophozoite Infectious stageReproduction
Means of InfectionRuptured skinInhaled through the noseEye http://www.youtube.com/watch?v=C6ZEHUg2bgk
Life Cycle
PathogenesisGranulomatous Amoebic Encephalitis
Attacks brain & spinal cordHeadachesStiff neckNauseaVomitingTirednessConfusionLack of attentionLoss of balanceSeizuresHallucinations
Immunocompromised
PathogenesisAcanthamoeba keratitis
Affects visionPainRedness Blurred visionSensitivity to lightSensation of something in the eyeExcessive tearing
Disseminated infection Infection throughout bodyRuptured skin
Diagnosis & TreatmentEarly diagnosis is essentialGranulomatous Amoebic Encephalitis & Disseminated
Infection Difficult to diagnose Brain scans Biopsies Spinal taps Ketoconaole, miconazole, itraconazole, fluconazole Amphotericin B
Acanthamoeba keratitis Scraping of eye Confocal microscopy Topical anti-microbial agents Combination of propamidine, miconazole, and neomycin.
Control VectorsUse proper contact lens hygiene
Visit eye care providerWash handsAvoid water
Unclear prevention for Granulomatous Amoebic Encephalitis & disseminated infection.
Review QuestionsWhat are the definitive and intermediate hosts of both
parasites?Where can these parasites be found in the
environment?Can Naegleria fowleri be spread from human to human?Name a disease caused by Naegleria fowleri.Name a disease caused by Acanthamoeba.What is the difference between the parasites’ cyst
stage?
References http://www.stanford.edu/group/parasites/ParaSites20
10/Katherine_Fero/FeroNaegleriafowleri.htm http://www.ncbi.nlm.nih.gov/books/NBK7960/ http://www.aoa.org/x8186.xml http://www.cdc.gov/parasites/acanthamoeba/ http://www.jstor.org/stable/4455900?seq=2 http://www.huffingtonpost.com/2011/12/17/brain-eati
ng-amoeba-death_n_1155334.html http://www.youtube.com/watch?v=C6ZEHUg2bgk http://webeye.ophth.uiowa.edu/eyeforum/cases/58-A
canthamoeba-Keratitis-Contact-Lens-Wear-Pain-Ring-Infiltrate.htm
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