Transcript Naegleria fowleri - Winona State University

Naegleria fowleri
& Acanthamoeba
Ashley Skellie & Karissa Jensen
Naegleria fowleri
Background
 Single-celled amoeba
 30+ Naegleria species
 Discovered in Australia
 Infections are rare
Taxonomy
Kingdom
Protista
Subkingdom
Protozoa
Phylum
Sarcomastigophora
Subphylum
Sacodina
Superclass
Rhizopodia
Class
Acarpomyxea
Order
Schizopyrenida
Family
Vahlkampfiidae
Genus
Naegleria
Species
fowleri
Geographic Distribution
 Worldwide
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United States
Australia
Czech Republic
Great Britain
Mexico
Czechoslovakia
 Prevalent in the summer
months
Hosts
 Definitive
 Humans
 Intermediate
 None
 Inhabitants of:
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Soil
Warm, freshwater
Geothermal springs
Recreational pools
Heated tap water
Means of Infection
 Inhaled through the nose
 Cannot spread from human to human
 Migrate to the brain via olfactory nerves
 Neti 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
Morphology
 Cyst
 8-12 um diameter
 Single-walled
 Spherical
 Trophozoite
 10-15 um diameter
 Infectious form
 Reproductive form
 Flagellated form
 Reproduce 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 & Treatment
 Early diagnosis is key
 Cerebral spinal fluid
 Tissue biopsy
 Autopsy
 Amphotericin B
 High toxicity
 Miconazole
 High mortality rate
Control Vectors
 Avoid swimming, diving, or jumping into water when
temperatures are high and water levels are low
 Hold head above water
 Hold nose shut; nose plugs
 Avoid digging up/disrupting sediment while swimming.
Acanthamoeba
Background
 Part of same superclass as Naegleria fowleri
 Microscopic amoeba
 Rare infection found worldwide
 Many species infect humans
 Accidently discovered in 1930
Taxonomy
Kingdom
Protista
Subkingdom
Protozoa
Phylum
Sarcomastigophora
Subphylum
Sacodina
Superclass
Rhizopodia
Class
Lobosea
Subclass
Gymnamoebia
Suborder
Acanthopodina
Family
Acanthamoebidae
Genus
Acanthamoeba
Hosts
 Definitive
 Humans
 Intermediate
 None
 Inhabitants of:
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All types of water
Heating, ventilating, and air conditioning systems
Dust
Soil
Morphology
 Cyst
 Double-walled
 Dormant
 Highly resistant
 Trophozoite
 Infectious stage
 Reproduction
Means of Infection
 Ruptured skin
 Inhaled through the nose
 Eye

http://www.youtube.com/watch?v=C6ZEHUg2bgk
Life Cycle
Pathogenesis
 Granulomatous Amoebic Encephalitis
 Attacks brain & spinal cord
 Headaches
 Stiff neck
 Nausea
 Vomiting
 Tiredness
 Confusion
 Lack of attention
 Loss of balance
 Seizures
 Hallucinations
 Immunocompromised
Pathogenesis
 Acanthamoeba keratitis
 Affects vision
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Pain
Redness
Blurred vision
Sensitivity to light
Sensation of something in the eye
Excessive tearing
 Disseminated infection
 Infection throughout body
 Ruptured skin
Diagnosis & Treatment
 Early diagnosis is essential
 Granulomatous Amoebic Encephalitis & Disseminated
Infection
 Difficult to diagnose
 Brain scans
 Biopsies
 Spinal taps
 Ketoconaole, miconazole, itraconazole, fluconazole
 Amphotericin B
 Acanthamoeba keratitis
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Scraping of eye
Confocal microscopy
Topical anti-microbial agents
Combination of propamidine, miconazole, and neomycin.
Control Vectors
 Use proper contact lens hygiene
 Visit eye care provider
 Wash hands
 Avoid water
 Unclear prevention for Granulomatous Amoebic
Encephalitis & disseminated infection.
Review Questions
 What 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/ParaSites2010/Katherine_Fero/Fero
Naegleriafowleri.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-eating-amoebadeath_n_1155334.html
 http://www.youtube.com/watch?v=C6ZEHUg2bgk
 http://webeye.ophth.uiowa.edu/eyeforum/cases/58-Acanthamoeba-KeratitisContact-Lens-Wear-Pain-Ring-Infiltrate.htm