zoonosis from fish to humans mainly through parasites. Reasons for them and how to prevent that are discussed

1. FISH BORNE PARASITIC
ZOONOSES
PRESENTED BY
R.BHARATHI RATHINAM
AAH-MA6-07

3. CONTENTS
• INTRODUCTION
• ZOONOSES
• IMPORTANT FISH BORNE PARASITIC ZOONOSES
• REASONS FOR PARASITIC
ZOONOSES
• PREVENTIVE MEASURES
• SUMMARY
• REFERENCES

4. INTROUCTION
• An important public health problem.
• Fish borne zoonotic cases started in late 1950s and
bloomed in 1980.
• Historically very few reports are there.
• Growth in aquaculture production, different
diagnostic techniques revealed this problem.
“ In some parts of the world such an raw
fish eating habit represents an established way
of life”
• Awareness needed among people about this
zoonoses.

5. Zoonosis
• A zoonosis is any disease or infection that is naturally
transmissible from animals to humans.
• Zoonosis may be bacterial, viral, or parasitic, or may
involve unconventional agents.
• Foodborne diseases caused by eating fishes which
have zoonotic potential parasitic infection is called as
FISH BORNE PARASITIC ZOONOSES.

6. • The fishborne parasites come from three main
groups:
Digenetic trematodes - especially species of
the families Opisthorchiidae and Heterophyidae;
Nematodes - mostly species of the families
Anisakidae and Gnathostomatidae;
Cestodes - species of the family
Diphyllobothriidae.

7. Digenetic trematodes
Trematodiasis
• Hetrophyidae (Heterophyes, Haplorchis, Metagonimus,
Ascocotyle (Phagicola) and Centrocestus) – Intestinal
flukes.
• Nanophyetidae – Salmon poisioning.
• Opisthorchiidae – Liver flukes (Clonorchis sinensis,
Opisthorchis viverrini and Opisthorchis felineus).

8. Disease Infectious agent
Acquired through
consumption of
Natural final hosts of
the infection
Clonorchiasis Clonorchis sinensis Fish
Dogs and other fish-
eating carnivores
Opisthorchiasis
Opisthorchis viverrini,
O. felineus
Fish
Cats and other fish-
eating carnivores
Fascioliasis
Fasciola hepatica,
F. gigantica
Aquatic vegetables
Sheep, cattle and
other herbivores

9. Large number of freshwater fishes (Cyprinids- liver flukes),
marine and brackishwater fishes for heterophidae.
• Integrated carp culture in earthen ponds.
• Mostly asymptomatic, high level infection cause damage in bile
duct epithelium, liver, and severe cases leads to
“cholangiocarcinoma” in case of liver flukes which is significant
than intestinal flukes(Intestinal histopathology).
• In 2005, more than 56 million people worldwide were estimated
to be infected with foodborne trematodes, and over 7000 people
died from infection.
• East Asia and South America are the most affected areas. (70)

10. • Some species endemic to some area like Thailand ,
Vietnam, Russia etc (clonorchiasis to south china)
• Mild diarrhea, abdominal discomfort are the clinical
signs. Diagnosis based on the eggs in stool sample.
• The public health burden to foodborne trematodiasis
is due to morbidity rather than mortality.
• Irradiation of the sweetfish by 200 Gy is highly
effective in controlling infectivity of metacercariae.
HAACP approach to fish pond management.

11. Treatment can be offered through preventive chemotherapy or individual
case management.
Disease
Recommended
drug and
dosage
Recommended strategy
Clonorchiasis
and
opisthorchias
is
Individual case management
Praziquantel:
– 25 mg/kg
three times daily
for 2–3
consecutive
days
– Treat all confirmed cases
– In endemic areas: treat all suspect cases
Preventive chemotherapy
Praziquantel:
–40 mg/kg in
single
administration
– In districts where the prevalence of infection
is
≥ 20%, treat all residents every 12 months
– In districts where the prevalence of infection
is
< 20%, treat all residents every 24 months, or
treat only those individuals reporting the habit
of eating raw fish, every 12 months

14. Nematodiasis
• Anisakidae and Gnathostomatidae

15. Anisakiasis
• Herring worm disease. Caused by Squid or Raw fish
eating habit of humans.
• Humans are accidental host, and for this parasite they
are dead end host.
• Diagnosis is by endoscopy, radiography.
• Symptoms: violent abdominal pain, nausea, and
vomiting. In some cases, can produce allergic reactions.
(An hour to two weeks after consumption)
• Most reports from Japan, Netherland, Spain.

17. • Diagnosis: patients vomit, immunoelectrophoresis,
immunofluorescence, indirect haemagglutination etc
• Because of the reason of Humans are the dead-end
host of anisakis, no treatment is needed in most cases.
• Treatment with albendazole, 400 mg twice daily for 21
days, has been used successfully in patients.
• The majority of infections involve gastric or intestinal
invasion. Tissue damage occurs because of the invasion
of the gut wall, development of eosinophilic
granuloma and colon cancer also.

18. Gnathostomiasis
• Humans – non required host (only for survival not
mature). Pigs, Dogs, Cats, Tigers etc. are definitive host.
• Throughout the world it is reported, but in humans
mainly tropical and subtropical areas.
• Mostly through raw Freshwater fish eating habit and
swallowing of infected water.
• Symptoms related to the movement of parasite
through the body. It diagnosed by someone have the
swelling under the skin that is move around the body.
Larva migrans.

19. • Initially it moves through the wall of stomach or
intestine or liver. (Early phase – no symptoms, 2 to 3
weeks)
• When it moves under the skin, swelling (pain). Rarely it
enters other part of body includes lungs, eyes, ears and
brain.
• If the parasite enters the eye – it can result in vision
loss, blindness.
• People who have a parasite moves on face are at high
risk.
• Two antiparasitic medications available are albendazole
and ivermectin.

21. Cestode - Diphyllobothriasis
• Diphyllobothrium latum. Largest tape worm which can
infect humans(30 feet).
• Mostly through freshwater fishes like salmon, trout,
perch etc. Generally occurs in Northern hemisphere.
• Diagnosis done by stool sample egg identification.
• Abdominal discomfort, vomiting, diarrhea etc.
• Intestinal blockage is a main problem and may cause
gall bladder disease
• Praziquantel or niclosamide are used mostly.

24. Reasons
• The development of new and improved diagnosis.
• The increase in raw fish consumption – caught from
polluted or parasite prevalent areas.
• By the increased consumption of regional fish dishes
such as sushi, sashimi, ceviche, carpaccio (raw or
minimally processed fish).
• By the growth in the international market in fish and fish
products.
• By the spectacular development of aquaculture.

25. • A range of parasites are well adapted and have
coevolved with their hosts so to persist in
relationships which may be sub-clinical or even
mutualistic in their nature, this would guarantee the
survival of both.
• Increased pet populations.
• Climatic change – global warming.

26. Preventive measures
• Action on animal vectors and reservoirs.
• Environmental and ecological changes.
• Avoiding particular harvest areas.
• Avoiding raw or undercooked consumption.
• Human behaviors and education.

27. • Fish borne parasitic zoonosis incidences are higher now
a days because of the diet and habit change of
humans, climate change, technology development.
• Sushi?? , Sashmi?? And all Raw under cooked items?
• We can eat but we should ensure that the fish was
caught from such a area, where the control limits of
the environmental parameters met.
• And most of the parasitic initial infection were
asymptotic, so if u ate raw fish then after a week, we
can check ourselves for the presence of parasite.

28. REFERENCES
• World health organization (www.who.int/)
• Fishborne zoonotic parasites and aquaculture: A review by
Carlos A.M. et al., Aquaculture 318 (2011) 253–261.
• Short communication “Fish-borne trematodes in cultured Nile
tilapia (Oreochromis niloticus) and wild-caught fish from
Thailand, by Benjamaporn Wiriya et al., (2013).
• Fish pathology, Roberts R.J
• Protozoan and metazoan diseases of finfish and shellfish, P.T.K.
Woo.
• Parasites of fish and risks to public health A.M. Adams et
al.,(1997).
• Invited review: “Fish-borne parasitic zoonoses: Status and
issues” Jong-Yil Chai et al., (2005).
• “Infectious Disease: Anisakiasis: General” GIDEON. 20 Feb.
2010 http://web.gideononline.com/web/epidemiology/

29. • Notable cases, First report of human anisakidosis in Australia,
By Shokoofeh Shamsi and Andrew R Butcher.
• Invited Review “Control and prevention of emerging parasitic
zoonoses.” Bruno B. Chomel * WHO (2008)
• www.cdc.gov.in.