Aetiology

Human or animal infection with larval stage

(Metacestod=Cyst) of Echinococcus:

E. granulosus Cystic echinococcosis, hydatidosis,

hydatid disease

E. multilocularis Alveolar echinococcosis,

alveolar hydatid disease

E.vogeli

E. oligarthrus Polycystic echinococcosis

(Hydatid cyst)

•Endocyst:

laminated layer

germinal layer with capsules

Protoscolex

•Pricyst

E. granulosus

E. multilocularis

life cycle of Echinococcus

Pathology

Slow growing & space occupying fluid filled cysts

In CE:

Liver 70%

Lungs 10-25%

Other organs <10%

In AE:

Liver 98-100%

Diagnosis

•Imaging techniques

•Parasitologic (Direct methods)

•Immunodiagnosis

Imaging techniques

MRI

Parasitologic

(PAIR)

Parasitologic

H & E

PAS

Ag

Eosin test: Incubation in 0.1% eosin in PBS Take up the stain =dead Exclude the stain= alive

Immunodiagnosis

o

o

o

o

CAgs

Immunodiagnosis

o

o

o

o

insensitive tests:

Casoni, CFT, LAT, IHA, IEP

replaced by new tests

IFA, ELISA, Immunobloting

Sensitivity = (TP/TP+FN) X 100

Specificity = (TN/TN+FP) X 100

Quality & Purity of Ag

CHFAg

AgB, Ag5

IFA (indirect fluorescent antibody)

Ag+Ab

IFAELISA

.1

•AbAg5(arc5)

.2(DD5)

.3

ELISA

Test sera in duplicate or triplicate

Control wells

blank, no sera, no Ag

Positive sera, Negative sera

Standard cut-off point:

SD of the negative controls3 mean O.D +

Sensitivity

%

Specificity

%

CHFAg 80-90 75-90

AgB 90 98

ELISA

AgB:

o polymeric lipoprotein, 120 KD

o thermo-stable

o highly immunogenic

o under reducing SDS-PAGE

Ag5:

lipoprotein, 400 KD

thermo-labile

Immunoblotting

Molecular

weight (kD)

Sensitivity

%

Specificity

%

8/16/24/38 91 93

8/16/24 95 90

8/16 81 100

8 78 100

.1ELISA

.2

DD5 or immunoblotting

Treatment

Surgery

PAIR

Chemothrapy

- Albendazole

- Mebendazole