entamoeba histolytica online

Entamoeba histolyticaEntamoeba histolyticaEntamoeba histolyticaEntamoeba histolyticaYakut Akyön YılmazYakut Akyön Yılmaz

Hacettepe university, Medical Faculty, Medical Microbiology Department

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AMOEBA

Sub phylum: SarcodinaSuper class: RhizopodaF il E bidFamily: EntamoebidaeOrdo: AmobidaClass: LoboseaClass: LoboseaGenus: EntamoebaSpecies: Entamoeba histolytica

Entamoeba hartmanniEntamoeba coliE t b l kiEntamoeba poleckiEntamoeba gingivalis

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Entamoeba histolyticaEntamoeba histolytica1875 Losch (Russia)1875 Losch (Russia)1886 Kartulis (Egypt)1913 Walker‐Sellards (Philipines)1913 Walker Sellards (Philipines)1891 Councilman‐Lafleur (USA)

1933 Chicago epidemy1950 Indiana epidemy1950 Indiana epidemy2002 Georgia epidemy

1900’ Emile Brumpt1970’ zymodem analyses1970 zymodem analyses1990’ molecularESCMID

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Entamoeba histolytica

Causative agent of the disease


Causative agent of the disease amoebiasis(old name : Amoebic Dysentery).(old name : Amoebic Dysentery).

dogs, cats and primates may be infected

parasite is primarily a human parasite and is transmitted from human to human.

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EPIDEMIOLOGYEPIDEMIOLOGY

• 10% world population is infected with Entamoeba histoltica/disparp

• Majority with non invasive E. dispar• 90% infections are asymptomatic• 90% infections are asymptomatic• 10% symptomatic

• Amoebiasis is the third most common cause• Amoebiasis is the third most common cause of death from parasite disease

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TRANSMISSIONTRANSMISSIONTwo forms

Cyst

TrophozoiteTrophozoite

Infective form is the cyst

Route faeco‐oral route

Rarel anal inoc lationRarely anal inoculation

Ingestion of food & water contaminated with cyst (hands)

ArthropodsArthropods ESCMID O

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Entamoeba histolyticaEntamoeba histolytica

Cyst (infectious) TrophozoiteCyst (infectious) TrophozoiteThick walled Plasmalemma (Thin)

1‐4 circular nucleus 1 circular nucleus

Spherical (14 – 20 µm) Irregular (12 – 17 µm)

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CystsInfective formCyst wall is resistant to environmental

conditions.Cysts remain viable in moist environment for 1 month

Remain alive in humidtyili d d i ill kill hBoiling and drying will kill them

susceptible to heat (above 40 °C), freezing (below –5 °C)

Can be detected in hard stool, can not be detected in watery diarheacan not be detected in watery diarheaESCMID

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TrophozoiteTrophozoiteMotile, living formCauses ameobiasisCauses ameobiasis

•Can spread to the body•Rarely can be responsible of transmission•Rarely can be responsible of transmission•Motile in diarheal stool•For diagnosis it should be fixed immediately•For diagnosis it should be fixed immediately or kept in +4 0C

• Trophozoites colonize the large intestine and invade the mucosaTrophozoites colonize the large intestine and invade the mucosa.

• They live within the crypts and mucosa of the large intestinal lining.

• Trophozoites may live and multiply indefinitely within the crypts of the large intestine mucosa feeding on starches and mucous secretions.

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Trophozoites and CystsTrophozoites and Cysts

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Entamoeba histolytica Trophozoites

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Entamoeba histolytica Cysts

Uninucleate cyst Binucleate cyst

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Entamoeba histolytica CystsEntamoeba histolytica Cysts

Quadrinucleate or mature cysts

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TYPESTYPESf f bi iTwo forms of amoebiasis1. intestinal amoebiasis2. extraintestinal amoebiasis

hepatichepaticpulmonarycerebralgenito urinarygenito urinary

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P i


PatogenesisTrophozoites dh i h li l lladhere to epithelial cellsresolve the mucosa epithelial cellsl i d i d hulceration and invade the mucosa

causes dysentery (diarhea + blood)d i bl d d l h ispreads via blood and lymphatic system

causes abscess extra‐intestinal in sites

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Adhesion is mediated by several cell‐surface proteins. One such adhesin is a multimeric protein complex with specific binding affinity for galactose (Gal) or N‐acetyl‐D‐galactosamine (GalNAc).

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Entamoeba histolyticaEntamoeba histolyticaClinical classification(WHO)( )

Asymptomatic infection (intestine) cyst spreaders

Symptomatic infection•Intestinal amebiasis(colon and rectum)•Intestinal amebiasis(colon and rectum)

Acute dysenteric (dysentery)Chronic non‐dysenteric (self‐limited)C o c o dyse te c (se ted)

•Extraintestinal AmoebiasisAmoebic Liver Abscess (ALA)Amoebic Pulmoner Abscess (APA)Other sites (brain, skin, genito‐urinary system ?)system,?) ESCMID

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Asymptomatic infection (intestine)Asymptomatic infection (intestine) “cyst spreaders”

•Most frequent•Asymptomatic for weeks months•Asymptomatic for weeks‐months

•Self‐limited•Two speciesTwo species

•E. histolytica (pathogen)•E. dispar (non‐pathogen)

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Entamoeba histolyticaEntamoeba histolyticaIntestinal Amoebiasis

Two typesAcute dysenteric (dysentery)Chronic non‐dysenteric (self‐limited, porter state)

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Colitis is the most common form of disease associated with amoebae

• Gradual onset of bd i l iabdominal pain, watery stools containing mucus and blood

• Some patients have only intermittent diarrhea l i i halternating with constipation

• Fever is uncommonFever is uncommon• Formation of ulcers

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Colitis is the most common form of disease associated with amoebae

• Amoeba invade mucosa and erode through laminia propria causing characterisitic flask shaped ulcersshaped ulcers.ESCMID

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CLINICAL FEATURESCLINICAL FEATURESI b i i d 2 6 kIncubation period 2‐6 weeks

Grumbling abdominal painTwo or more unformed stools/dayPeriods of diarrhoea alternating with constipationMucous and or blood mixed stool/ offensive odourucous a d o b ood ed s oo / o e s e odouTenderness in lower abdominal regionTenesmusTenesmusFever, uncommon (% 33)

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Ch i bi i ( i )Chronic amoebiasis (carrier)37% symptomatic (5 years)Intermittent diarrhea, mucus, abdominal pain and/or weight lossTrophozoites in stool (rarely cyst)Serologically positive

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Ulceration can lead to secondary infection and extraintestinal lesions

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COMPLICATIONSCOMPLICATIONS

Toxic megacolon, after wrong treatment with steroids

Amoeboma (rare) can be mis‐diagnosed as cancer

f l lAcute fulminant colitis

Peri anal ulceratione a a u ce at o

Stricture & intussusceptions & peritonitis

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Diagnosis:Ova/parasite examination; trophozoite cystOva/parasite examination; trophozoite, cystConcentration methods; cystTrichrome staining (permenant staining)Trichrome staining (permenant staining)SigmoidoscopySerologic tests (chronic cases)Serologic tests (chronic cases)

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FEATURESFEATURES AMOEBIC DYSENTRYAMOEBIC DYSENTRY BACTERIALBACTERIALFEATURESFEATURES AMOEBIC DYSENTRYAMOEBIC DYSENTRY BACTERIAL BACTERIAL DYSENTRYDYSENTRY

INCUBATION PERIODINCUBATION PERIOD LongLong shortshort

ONSETONSET InsidiousInsidious AcuteAcute

SYMPTOMSSYMPTOMSLow abd pain, fever Low abd pain, fever

absent, volume of stool absent, volume of stool copious mod tenesmuscopious mod tenesmus

Generalised abd pain, Generalised abd pain, fever, volume of stool fever, volume of stool less severe tenesmusless severe tenesmuscopious, mod tenesmuscopious, mod tenesmus less, severe tenesmusless, severe tenesmus

LAB DIAGLAB DIAG Few pus cellsFew pus cells numerous pus cellsnumerous pus cellspp pp

STOOL STOOL MICROSCOPYMICROSCOPY

Trophozoites with Trophozoites with ingested RBCsingested RBCs

No trophozoitesNo trophozoitesMICROSCOPYMICROSCOPY gg

CULTURECULTURE Bacilli not Bacilli not demonstrateddemonstrated

Dysentery bacilliDysentery bacilli

Extraintestinal amoebiasisESCMID O

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E t i t ti l bi iExtraintestinal amoebiasis

Amoebic Liver abscess (ALA)Amoebic pulmoner abscess (APA)p ( )Other sites (brain, skin, genito‐urinary system,?)

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Amoebic Liver abscess(ALA) (ALA)

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PATHOGENESISPATHOGENESISI i f h i i l &• Invasion of trophozoites into portal system & reaches liverI fil i f hil i li• Infiltration of neutrophils into liver

• Lysis of neutrophils on contact with amoeba• Release of neutrophil toxin & damage liver

parenchyma• Necrosis of parenchyma & abscess formation filled

with chocolate brown pus• Usually abscess forms in postero‐superior quadrant

of the right lobe of liver

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CLINICAL FEATURESCLINICAL FEATURESd h dLead symptoms are right upper quadrant

pain and feverDiscomfort & tenderness in right hypochondriumhypochondriumPain in right shoulderS i i & iSwinging temperature & sweatingCough, malaise, & loss of appetiteg , , ppJaundice uncommon

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COMPLICATIONSCOMPLICATIONS

Pleural effusion

Hepato bronchial fistula

Left lobe abscess may rupture intoLeft lobe abscess may rupture into peritonial cavity, pleural space or pericardial cavity

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Patient with amoebiasis liver absess, with perforation of abscess through abdominal skin.

Gross Pathology of amoebic liver abscess

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Entamoeba histolyticaEntamoeba histolyticaDiagnosis:g

Stool examinationCBC (leucocytosis?)CBC (leucocytosis?)Radiology (CT; MRI)SerologySerologyCultureExamination of aspiration fluidExamination of aspiration fluid

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Pus from aspiration fluid

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Pulmonary AmoebiasisPulmonary Amoebiasis

• Direct pulmonary infection (blood circulation)

• Secondary infection; after liver amoebiasis atSecondary infection; after liver amoebiasis at the right pulmonary

C i l l b– Cases single or several abscess

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Cerebral AmoebiasisCerebral Amoebiasis

• Occur from complications of liver and pulmonary amoebiasis p y– Cases single or several abscess

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Spleen and Cutaneous Amoebiasis

l b l h l• Spleen abscess is always seen with liver amoebiasis

• Cutaneous amoebiasis is seen in perianal site

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Amoebic Amebiasis of the SkinAmoebic Amebiasis of the Skin

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Amoebiasis cutis: Clinical suspicion is the key toearly diagnosisajd_594 52..55Ghanshyam K Verma,1 Nand Lal Sharma,2 Vinay Shanker,1 Vikram K Mahajan,1 Rajani Kaushik,3Santwana Verma4 and Nidhi Jindal1 (INDIA)

Figure 1 (a) Amoebiasis cutis lesionshowing hyperpigmented borders, discoloration,pus discharging from sinuses andcharacteristic ulcers over the plaque.(b) Close-up view of (a) Also note(b) Close up view of (a). Also note condylomatalata-like nodular lesions aroundanal orifice.

3 years earlier as a painful nodule in the perianal regionwhich ulcerated discharging purulent material. The ulcerincreased gradually to involve the buttocks, perineum andincreased gradually to involve the buttocks, perineum andpart of the left upper thigh. Historically, there were infrequentepisodes of constipation or blood mixed loose stools.He had been previously investigated for cutaneous tuberculosis

d C h ’ di C lt d l h iand Crohn’s disease. Culture and polymerase chainreaction studies on the pus were negative for Mycobacteriumtuberculosis while proctoscopy and barium enema werenormal. Escherichia coli cultured from the pus was sensitivenormal. Escherichia coli cultured from the pus was sensitiveto ciprofloxacinESCMID

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DIAGNOSISDIAGNOSIS

• SHOULD BE DIFFERENTIATED FROM NON‐PATHOGENIC AMOEBA

• STOOL EXAMINATION

TRICHROME STAIN (PERMENANT)• TRICHROME STAIN (PERMENANT)

• STOOL ANTIGEN TEST ELISA (MONOCLONAL (AB E. histolytica adhesine)

MOLECULAR (PCR REAL TIME PCR)• MOLECULAR (PCR, REAL TIME PCR)

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Amoebic liver abscess Amoebic liver abscess visualized on a computed visualized on a computed

tomogramtomogram(Peters and Pasvol, 2002)(Peters and Pasvol, 2002)

CT scan guided aspiration of CT scan guided aspiration of amoebic liver abscess with amoebic liver abscess with

chocolate coloured pus chocolate coloured pus (anchovy sauce)(anchovy sauce)

(Peters and Pasvol, 2002)(Peters and Pasvol, 2002)ESCMID O

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The treatment of Entamoeba histolytica

F i i f i• For asymptomatic infections, iodoquinol, paromomycin, or diloxanide furoate

(limits the spread of cysts)• For symptomatic intestinal disease, or extraintestinal, infections (e.g., hepatic abscess), metronidazole or tinidazole, immediately followed by treatment with iodoquinol, paromomycin, or diloxanide furoate.

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PREVENTION/CONTROLPREVENTION/CONTROLDiagnose and treat patientsDiagnose and treat patients

Wash hands with soap & water at least 10 seconds after using toilet or changing baby diaperafter using toilet or changing baby diaper

Clean bathroom & toilets often

Avoid sharing towels

Avoid eating raw vegetables, wash them wellg g ,(endemic areas)

Boil water or treat with iodine tablets or filterBoil water or treat with iodine tablets or filter (0.22 filtration)

Prevent food contamination with stoolPrevent food contamination with stoolESCMID O

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E. histolytica Diagnosis by Real‐time PCR

• 230 stool samples 22 positive for E. histolytica (% 9.6)y ( )

Yakut Akyön Yılmaz, Fadile Zeyrek, Ahmet Pınar, Alpaslan Alp, Sibel Ergüven

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Entamoeba histolytica – AMOEBIASIS, AMEBIC DYSENTRY; AMOEBIC LIVER ABSCESS

S d l i l f METASTASIS f

DYSENTRY; AMOEBIC LIVER ABSCESS

• Secondary lesions occur as a result of METASTASIS of trophozoites to extraintestinal organs – liver is most frequently affected – Hepatic amoebiasis; pulmonaryfrequently affected – Hepatic amoebiasis; pulmonary amebiasis; cerebral ameobiasis; cutaneous amebiasis; spleenic abscess.p

• Symptoms: Diarrhea; dysentery – stool containing blood, mucous and shreds of necrotic mucosa, acute abdominal pain, tenderness and fever. Chronic ameobiasis – recurrent attacks of dysentery. Abd i l t d HEPATOMEGALY i ht lAbdominal tenderness, HEPATOMEGALY; weight loss and emaciation.

SUMMARYESCMID O

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Entamoeba histolytica – AMOEBIASIS, AMEBIC DYSENTRY; AMOEBIC LIVER ABSCESS

Lif l i h bit th l i t ti th t i• Life cycle: inhabit the large intestine; the cyst is the infective stage. On ingestion – excyst into amoebulae – trophozoites which is the vegetativeamoebulae trophozoites which is the vegetativestage – invade the mucosa to absorb nourishment from tissues dissolved by its ycytolytic enzymes and also ingest RBCs.

• Pathology and Symptomatology: primary lesion is ULCER ‐ invasion of the wall of large intestine –ulcer is flask shaped. Complications – amoebic granuloma (amoeboma); appendicitis stricturegranuloma (amoeboma); appendicitis, stricture, intestinal perforation

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entamoeba histolytica online

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