encephalitis caused by naegleria fowleri and others
TRANSCRIPT
8/7/2019 Encephalitis caused by Naegleria fowleri and others
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Encephalitis caused by Naegleria
fowleri and others amoebas.
Guillermo Roberto Guevara Morales
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Naegleria fowleri
Flagellate stage
Trophozoite
Cyst stage
Different stages of Naegleria fowleri
�Is a free-living amoebae.
�typically found in warm bodies
of fresh water, such as ponds,lakes, rivers, and hot springs.
� N. fowleri can invade and
attack the human nervous
system.
�An infection will nearly always
result in the death of the victim.
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others amoebas
� Acanthamoeba
� A. castellani
� A. polyphaga
� Balamuthia
� B. mandrillaris
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History
� Between 1958 and 1961, Clubertsonsuggested that free-living amoebae may causealterations in humans
� Fowler and Carter first described humandisease caused by amebo-flagellate inAustralia in 1965
� In 1966, Butt reported the first case of Nfowleri meningoencephalitis .
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Lifecycle
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Pathophysiology
1. penetrate the submucosal
nervous plexus, cross the
cribriform plate, and gainaccess to the subarachnoid
space
2.The presence of protein and glucose
in the (CSF) supports the growth of
amebae
3.The invasive trophozoites
are highly phagocytic and
ingest RBCs and brain tissue,
resulting in severe
hemorrhagic necrosis of the
involved brain.
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CLINICAL MANIFESTATIONS
� Abrupt onset
� IP: 2-5 days
� Fever
� headache
� disturbances of smell and taste.
� signs of meningoencephalitisin± nuchal rigidity
± Lethargy
±
Confusion± altered level of consciousness.
± Seizures are common.
� Death occurs within a week of onset of symptoms
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Granulomatous amebic encephalitis
caused by Acanthamoeba
� Insidious onset
� progressionof manifestations occurring weeksto months after exposure
� personality changes
� Seizures
� Headaches
� nuchal rigidity
� ataxia
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diagnosis
� Cerebrospinal fluid test satined with Wright,
Giemsa o H&E.
� Asimple agar and E. Coli culture
� Brain biopsy
� Additional methods
±
PCR± CT
CSF protein levels are
elevated.
CSF glucose levels are
within the reference range
or reduced.CSF WBC count is elevated
(400-26,000 cells/µL).
CSF RBC count is high.
CSF Gram stain results are
negative for bacteria.
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References
� WebMD (May 29, 2008). Brain eating amoeba strikes in summer.Retrieved May 14, 2009, fromhttp://www.webmd.com/news/20080529/brain-eating-amoeba-strikes-in-summer
� Mayoclinic.com (2009). Naegleria fowleri. Retrieved May 16, 2009,
from http://mayoclinic.com/health/naegleria-infection/DS01066� CDC (2009). Parasitic disease information. Retrieved May 16, 2009,
fromhttp://www.cdc.gov/ncidod/dpd/parasites/naegleria/factsht_naegleria.htm
� CDC (2009). Naegleria infection. Retrieved May 17, 2009, fromhttp://www.cdc.gov/ncidod/dpd/parasites/naegleria/moreinfo_naegleria.htm#reports
� CDC (2009). Naegleria fowleri in well water. Retrieved May 24,2009, from http://www.cdc.gov/eid/content/14/9/1499.htm
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Treatment
� Amphotericin B.
±
miconazole IV
± rifampin
± Sulfonamides
± chloramphenicol
± tetracycline