Dr. Zahid Iqbal Mir, MBBS, MS (General Surgery), DNB (General Surgery) has done his bachelors and masters in General Surgery from the prestigious Govt Medical College Jammu and DNB in General Surgery from NBEMS New Delhi. He is a passionate surgeon, earlier practising at Government Medical College, Jammu as Registrar in Department of General Surgery. Nowadays working as Senior Resident in Department of General Surgery, Government Medical College & Hospital, Sector 32, Chandigarh and a rising name in field of surgery. He is an enthusiastic, enigmatic and dedicated teacher as well. He is not just a resolute learner, but also an awe inspiring guiding light for his juniors, which makes him the most loveable and respected senior.

1. LIVER HYDATID DISEASE
INTRODUCTION , EPIDEMIOLOGY, MORPHOLOGY, PATHOGENESIS
Presenter. : Digvijay Singh (30)
Moderators : Dr. Zahid Iqbal Mir
Dr. Sanjay Gupta

2. HISTORY
✓Livers full of water - Hippocrates
✓Echinococcus - Greek origin meaning Hedgehog
berry
✓Hydatid means drop of water (hudatid, hudatis –
Greek ) or watery vesicle ( hydatis- Latin)
✓Pallas & Goeze (1760) demonstrated the parasitic
nature of watery cysts in animals
✓Echinococcus - first used by Rudolphi, who
demonstrated the presence of the Cestode, its head,
suckers & hooklets in hydatid cyst in humans
✓First case (1808)- published (1822)

3. WORLD
South America
western China
M e d i t e r r a n e a n
countries
Eastern Europe
Northern Africa
Central Asia
Tropics (India &
Nepal)
INDIA
UP
Tamil nadu
Andhra Pradesh
Punjab
Kashmir
Pondicherry
Cystic echinococcosis - globally distributed - every continent
except Antarctica
Alveolar echinococcosis - northern hemisphere, in particular
to regions of China, the Russian Federation and countries in
continental Europe and North America

4. EPIDEMIOLOGY
Incidence
In Areas of endemicity
1 to 200 per 100,000 (CE)
0.03 to 1.2 per 100,000 (AE)
India is ranked first in CE cases with 12% (119,320 cases)
reported from India out of 973,662 global human CE cases
Mortality
2-4%(CE), increases considerably if inadequately managed
90% (AE) within 10-15yrs of diagnosis
For CE - average of 2.2 % post-operative death rate , 6.5 %
cases relapse
Hotez PJ, Damania A (2018) India’s neglected tropical
diseases. PLoS Negl Trop Dis 12(3): e0006038

5. HUMAN CYSTIC ECHINOCCOSIS RESEARCH IN
CENTRAL AND EASTERN SOCIETIES (HERACLES)
Collaborative, translational public health
project on cystic echinococcosis, funded by
the European Commission
SOUTH AMERICAN INITIATIVE FOR THE
SURVEILLANCE, DIAGNOSIS AND CONTROL OF CE
6 countries (Argentina, Brazil, Chile, Paraguay, Peru and Uruguay) are involved
in the initiative, which is coordinated by the zoonosis unit at the Pan American
Foot-and-Mouth Disease Center PANAFTOSA within the Pan American Health
Organization/WHO Regional Office for the Americas (PAHO/WHO). The
objectives are to stimulate governance and formulate strategies and action
plans for the control and elimination of CE as a public health problem in the
Region.

6. THE EUROPEAN REGISTER OF CYSTIC ECHINOCOCCOSIS
October 2014
Prospective, observational, multicentre
register of patients with probable or
confirmed CE, for which data are collected
prospectively to address specific research
questions (e.g. spontaneous or treatment-
induced evolution of cysts over time) and
help overcome the lack of prospective
studies.

8. AGENT
• Larval stage of Echinococcus granulosus (dog tapeworm)
HOST
• Definitive host – Carnivorous predators – dogs, wolves,
foxes, and lions.
• Intermediate host - Sheep, goats, cattle, camels, pigs, wild
herbivores, and rodents are the usual intermediate hosts,
but humans can also be infected. Humans are dead-end
hosts.
ENVIRONMENT
Ingestion of water or food contaminated with tapeworm eggs
Rainy season and the high humidity of the soil.
EPIDEMIOLOGICAL DETERMINANTS

9. ✓ a.k.a hydatidosis or echinococcosis is a cyclozoonoses
caused by larval ( metacestode ) stages of flat worms
( cestodes ) of genus Echinococcus and family Taeniidae.
✓ Species known to cause infection in humans
• E. granulosus - cystic echinococcosis
• E. multilocularis - alveolar echinococcosis.
• E. vogeli & E. oligarthrus - polycystic echinococcosis
• E.ortleppi – cystic echinococcosis
✓ Other species - transmission to humans is not known.
• E. equines
• E. shiquicus - small mammals from Tibetan plateau
• E. felidis in African lions
Jenkins DJ, Romig T, Thompson RC. Emergence/re-emergence of Echinococcus spp - a global update. Int J Parasitol 2005; 35:1205
PARASITOLOGY

10. MORPHOLOGY
Echinococcus granulosus (adult worm) Echinococcus egg in feces.
(Stool sample light microscopy at 100x)
Larval stage (hydatid cyst)-
described later in pathogenicity

11. MODE OF TRANSMISSION
• Ingestion of the eggs of Echinococcus
• Handling infected dogs- hand to mouth transfer,
inhalation of contaminated dust—not from person
to person.
• Dog-sheep cycle
• Other animal combinations
➢ dog-goat, dog-cattle, and dog-camel

14. DEVELOPMENT
• Eggs transform to larva (hydatid cyst): In
duodenum, the oncosphere is released by the
rupture of embryophore. It penetrates into the
intestinal wall, enters the portal circulation and
carries to the liver (60–70% of cases) or lungs or
rarely to other organs.
• Hos
t­
immune response —oncospheres destroyed
—few escape destruction — hydatid cyst.
• Increases in size at a rate of 1 cm/month. Full
development ( 10–18 months in sheep)
• Infective to dog and other definitive hosts

15. PATHOGENICITY
HYDATID CYST
Unilocular, subspherical, shape
and size varies from few
milimeters to more than 30 cm
(usual size 5–8 cm).
It appears as fluid filled bladder
like cyst.
Cyst wall consists of three layers:
•Pericyst (outer layer, host
derived)
•Ectocyst (middle layer, parasite
der
i­
ved)
•Endocyst (inner layer, parasite
derived)

16. HYDATID FLUID: Clear, colorless to pale yellow
pH - 6.7, Specific gravity - 1.005 to 1.010
Chemical composition: sodium chloride, sodium sulfate, sodium
phosphate and succinates.
• Antigenic, toxic and anaphylactic
HYDATID SAND: Brood capsules and protoscolices - break off
VARIETY OF HYDATID CYST:
• Primary cyst
• Secondary cysts
• Acephalocyst Cysts without brood capsules and protoscolices
• Endogenous daughter cysts
FATE OF THE HYDATID CYST:
• Spontaneous resolution
• Rupture of the cyst - Secondary cysts - or Anaphylactic reaction

18. IMMUNE RESPONSE
✓ Intermediate + Incidental hosts - Humoral + cellular
immune responses to the organism
✓ Initial immune response - against the oncospheres that
penetrate the gastrointestinal mucosa
✓ Subsequent response - against the metacestode
(hydatid cyst)
✓ Other less well-defined mechanisms- parasite derived
modulating substances such as an anticomplement
factor
Th1 cell activation — protective immunity
Th2 cell activation — susceptibility to progressive hydatid disease.

19. ✓ Avoid close contact with dogs
✓ Careful washing of fresh products
✓ preventing dogs from consuming infected sheep viscera
✓ Elimination of stray dogs
✓ Surveillance in dogs - administering arecoline hydrobromide
with subsequent stool evaluation for worms or eggs. / Stool
antigen test
✓ Administration of praziquantel to infected dogs
✓ Vaccine for E. granulosus, - EG95 vaccine (Sheep)
Prevention of alveolar echinococcosis (AE)
• Avoidance of contact with foxes and other potentially infected
definitive hosts
Prevention and Control

21. EG95 VACCINE
• Recombinant vaccine
• produced in Morocco and used to
vaccinate sheep in combination with
clostridial antigens.
• The combined EG95/clostridial vaccine
induced specific anti-EG95 antibody
responses in all animals after two
immunizations.

22. REFERENCES