a detailed explanation of infection echinococcosis

1. ECHINOCOCCOSIS
-LADI ANUDEEP
ISM-IUK

2. ETIOLOGY
• Echinococcosis is a parasitic disease of tapeworms of echinococcus
type.
• The two main types of the disease are cystic echinococcosis and
alveolar echinococcosis
• Less common forms include polycystic echinococcosis and unicystic
echinococcosis.
• The disease often starts without symptoms and may last for years.
• The symptoms and signs depend on localization and size of cyst.

3. CLASSIFICATION
• The most common form found in humans is cystic echinococcosis(
unilocular echinococcosis) which is caused by echinococcus
granulosus sensu lato
• 2 nd most common form is alveolar echinococcosis( alvelolar hydatid
dieasease) which is caused by echinococcus multilocularis
• 3rd most common form is polycystic echinococcosis( human polycystic
hydatid disease) caused by echinococcus vogeli and E. oliharthrus

4. EPIDEMOLOGY
• The disease is spread when food or water that contains the eggs of
parasite is eaten.
• Also spread by close contact with infected animal
• The eggs are released in stool of meat eating animals that are
infected by parasite.
• Commonly infected animals include dogs, foxes, wolves.
• For these animals to become infected they must eat organs of
animals that contains cysts such as sheep or rodents

5. Very few countries are considered to be free of E.granulosis.
The areas of world with high infection are rural ,grazing areas where
dogs are able to ingest organs from infected animal.
E.Multilocularis mainly occurs in northern hemisphere ,northern parts
of Europe ,Asia, Northamerica.
Unlike the two species of echinococcosis E.vogeli and E.oligarthus are
limited to central and Soutamerica

6. LIFE CYCLE

7. CLINICAL FEATURES
• In humans, E. granulosus, multilocularis, oligarthrus, vogeli are localized in
liver(75%), in lungs(5-15%), spleen, brain , heart , kidneys(10-20%)
• The cysts are filled with clear fluid called hydatid fluid
• If the patient has cyst in lungs and is symptomatic, they will have cough, dyspnea,
pain in chest
• If patient has cyst in liver and is symptomatic, they will have abdominal pain,
tenderness, hepatomegaly with abdominal mass, jaundice, fever, anaphylactic
reaction, cysts can rupture into the biliary tree and produce biliary colic,
obstructive jaundice, cholangitis, or pancreatitis
• If cyst rupture in the body during surgical extraction of cyst or by trauma, the
patient goes to anaphylactic shock and suffer from pruritus, edema of lips and
eyelids, dyspnea, stridor, rhinorrhea.
• Incubation period lasts from months to years

8. For E. granulosus:
• The initial phase of primary infection is always asymptomatic. Many
• infections are acquired in childhood but do not cause clinical
manifestations until adulthood.
• Latent periods of more than 50 years before symptoms arise have been
reported.
For E. multilocularis:
• usually symptomatic, although the clinical manifestations are frequently
nonspecific.
• The most common presenting complaints include malaise, weight loss, and
right upper quadrant discomfort due to hepatomegaly, Cholestatic
jaundice, cholangitis, portal hypertension, and the Budd-Chiari syndrome

10. DIAGNOSIS
• Usually by CT, US, MRI
• For cystic echinococcosis diagnosis, imaging is the main method while
serology tests( indirect hemogglutination, ELISA) that use antigen
specific for E. granulosis verify imaging results and US is the imaging
of choice because it is employed most widely and it is easy to perform
and relatively inexpensive
• For alveolar echinococcosis, US is the imaging technique of choice. It
is also important to note serology tests which are more valuable for
diagnosis. PCR, tissue biopsy are other ways to diagnose alveolar
echinococcosis
• Polycystic echinococcosis particularly US, CT scans are useful

11. Treatment
• Cystic and alveolar: open surgical removal of cyst with chemotherapy
using albendazole(10 to 15 mg/kg per day in two divided doses; usual
adult dose 400 mg twice daily for 2 years) before and after surgery
• For inoperable cases, chemotherapy and PUNCTURE ASPIRATION
INJECTION REASPIRATION become alternative options of treatment
• Albendazole is used 2 times a day for 1-5 months
• Alternative to open surgery is laparoscopic surgery which provides
excellent cure rates with minimum morbidity and mortality