Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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PARASITIC ZOONOSES
ARTHROPOD INFECTIONS
Pentastomid Infection
Linguatula serrata, Armillifer spp.
Human:
1. L. serrate irritation of throat, larynx, and/or nose sometimes
accompanied by dyspnea, vomiting, lacrimation, and
headache. Self-limiting in a day to 1-3 weeks.
2. Amillifer spp.; usually asymptomatic but may produce
pneumonia or peritonitis.
Incubation period: 1R hour
Case fatality rate: None. Self-limiting.
Confirmatory tests:
1. Microscopic examination of saliva or nasal secretions to
identify larval stage of parasite.
Occurrence:
2. Dogs are primary definitive host
3. sheep and goats are major
4. intermediate hosts.
Transmission :
1. ova in feces or nasal discharge from infected dogs are
ingested by sheep, goats, or humans.
2. Intermediate hosts (including humans) ingest ova in water or
raw snake meat.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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CONTROL AND PREVENTION
1. Avoid contact with dog feces
2. Boil drinking water
3. Cook snake meat.
4. Prevent feeding of raw viscera of sheep or goats to dogs.
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CESTODE INFECTIONS
Echinococcosis/Hydatidosis
Echinococcus spp. (E. granulosus, E. multilocularis, E. oligarthrus,
E. vogeli)
Human:
1. Varies with organ infected
2. most commonly the liver
3. Many infections asymptomatic and only discovered during
surgery or necropsy.
4. Clinical signs may include hepatomegaly ascites, swollen
abdomen, or dull abdominal pain.
5. Rupture of cyst formed in liver may produce anaphylaxis.
Incubation period: Months to years before illness ensues.
Case fatality rate: Very high; 50%-75%.
Confirmatory tests:
1. Radiographic or ultrasonographic observation of space
occupying lesion.
2. Hemmagglutination, immunofluorescence,
immunoelectrophoresis, or ELISA testing of serum.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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3. Confirm by microscopic examination of tissues (obtained
during surgery) for free scolices or daughter cells.
Occurrence:
1. E. multilocularis (alveolar form), rural areas of the northern
hemisphere.
2. E. granuIosus (unilocular or cystic form), the Mediterranean
coast, Middle East, southern South America, southern Russia,
northern Africa, Australia, and New Zealand.
3. E. vogeli (polycystic form), South America.
Transmission:
1. ingestion of dog feces
2. eating food contaminated with dog feces.
CONTROL AND PREVENTION
1. surgical extirpation of the cyst or cysts.
2. Mebendazole may produce some regression of cysts, if
surgery is not feasible.
3. Educate public regarding method of transmission
4. institute good personal hygiene.
5. Wash food potentially contaminated with dog feces.
6. Prevent dogs from eating the viscera of ungulates or rodents.
7. Treat dogs with praziquantel or niclosamide.
8. Eliminate stray dogs.
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Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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Taeniasis
Taenia spp. (T. saginata, T. solium. Occasionally T. ovis T.
hydatigena, T.taeniaeformis)
Human:
1. Usually asymptomatic.
2. May produce digestive disturbances, abdominal pain,
anorexia.
3. Infection with the larval stage of T. solium (cysticercosis)
can produce severe response which will vary depending upon
location of organisms (brain-neurologic signs, heart-may be
fatal).
Incubation period 8-14 weeks.
Case fatality rate: Low except for cysticercosis, which is high
without treatment .
Confirmatory tests:
Microscopic identification of proglottids from feces or ova from
tape applied to anal area.
Occurrence:
1. Worldwide.
2. Most common where beef or pork is eaten raw or
undercooked.
3. T. solium is most common in developing countries.
Transmission:
1. Ingestion of cysticerci in raw or undercooked beef or pork.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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2. T. solim can be transmitted by ingestion of ova
(cysticercosis).
CONTROL AND PREVENTION
1. Treat with niclosamide, praziquantel, or quinacrine
2. Hydrochloride
3. Cook meat thoroughly .
4. Prevent contamination of swine or cattle feed with human
fecal waste.
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Diphyllobothriasis
Diphyllobothrium spp. In humans, primarily D. latum
Human:
1. Often asymptomatic with occasional segments in feces as
only sign of infection.
2. Approximately 50% of infections are associated with
diarrhea, anorexia, nausea, vomiting, and weight loss.
3. A craving for salt is common.
4. Occasionally a macrocytic,
5. hyperchromic anemia develops as a result of the parasite
competing with the host for vitamin B12.
Animal: Usually subclinical.
Incubation period. 3-6 weeks.
Conflrmatory tests: Microscopic examination of fresh feces
Transmission:
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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1. Consumption of raw or undercooked fish that have ingested
infected copepods
CONTROL AND PREVENTION
1. Treat with niclosamide, quinacrine, or praziquantel.
2. In endemic areas, heat fish to 56"C/132"F for 5 minutes, or
freeze at - 10°C/14"F for 48 hours.
3. Educate public regarding method of transmission.
4. Institute proper fecal waste disposal.
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TREMATODE INFECTIONS
Fascioliasis
Fasciola spp. (F. hepatica, F. gigantica)
Human:
1. Often asymptomatic.
2. Abdominal pain, diarrhea, icterus.
Incubation period Variable. 6-16 weeks.
Case fatality rate: Low.
Confirmatory tests: Microscopic examination of feces or bile
Occurrence: worldwide.
Transmission: Ingestion of aquatic plants with encysted
metacercariae. Cercariae develop in snails inhabiting water
contaminated with feces of infected herbivores.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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CONTROL AND PREVENTION
1. Treat people with bithionol or praziquantel.
2. Treat infected herbivores with triclabendazole.
3. Avoid eating aquatic plants without first cooking in endemic
areas.
4. Cook liver from herbivores in endemic areas.
5. Education regarding method of transmission.
6. Eliminate snail intermediate hosts.
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Dicroceliasis
Dicrocelium spp. (D. dendriticum, D. hospes)
Human: Usually asymptomatic. Colic, diarrhea, flatulence.
Confirmatory tests: Microscopic examination of fresh feces
Occurrence: Worldwide. Reservoir cattle, sheep, other herbivores.
Transmission:
1. Ingestion of metacercariae in ants.
2. Cercariae develop in land snails inhabiting pasture
contaminated with feces of infected herbivores.
3. Ants become infected when feeding on snails.
CONTROL AND PREVENTION
1. Treat with bithionol or praziquantel.
2. Avoid chewing on plants in endemic areas.
3. Treat infected herbivores with hetolin or thiabendazole.
4. Education regarding method of transmission.
5. Control snails.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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NEMATODE INFECTIONS
Ascariasis
AGENT
Ascaris suum
Human:
1. Initially, respiratory distress, coughing, and fever associated
with pulmonary migration of larvae.
2. Intestinal phase usually mild unless parasite load is heavy, in
which case there may be colic, vomiting, and diarrhea.
Animal: Same as human.
Incubation period: 2 weeks until the respiratory phase begins; 2
months until the intestinal phase.
Case fatality rate: Very low
Confirmatory tests: Microscopic examination of fresh feces for ova
Occurrence:
1. Most common in warm, humid climates.
2. Swine are the normal reservoir.
Transmission: Ingestion of ova in contaminated soil or on fresh
vegetables.
CONTROL AND PREVENTION
1. Treat with albendazole, mebendazole, or pyrantel
2. Sanitary disposal of swine feces.
3. Steam clean concrete
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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Capillariasis
1. Capillaria hepatica, hepatic form;
2. Capillaria philippinemis, intestinal form;
3. Capillaria aerophila, pulmonary form
Human:
1. hepatomegaly, splenomegaly, intermittent fever, nausea,
vomiting, diarrhea, edema, and ascites.
2. Intestinal-abdominal pain, intermittent diarrhea, weight loss.
3. Pulmonary-asthmatic breathing, cough, fever, mucoid or
bloody expectoration.
Animal: Same as human.
Incubation period: 3-4 weeks.
Case fatality rate: Approximately 10%. Higher if untreated.
Confirmatory tests:
Hepatic: Microscopic examination of liver biopsy for ova of C.
hepatica.
Intestinal: Microscopic examination of fresh feces for ova, larvae,
or adults
Pulmonary: Microscopic examination of sputum and feces for ova
Occurrence:
1. Hepatic: Worldwide. Rats are major reservoir.
2. Intestinal: Southeast Asia (Philippines and Thailand).
3. Pulmonary: Cases reported from Russia and Middle East.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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Transmission:
1. Hepatic and pulmonary: Ingestion of soil contaminated with
ova or infective larvae.
2. Intestinal: Ingestion of raw or undercooked fish containing
infective larvae.
CONTROL AND PREVENTION
1. Treat with mebendazole.
2. Prevent ingestion of soil potentially contaminated with ova or
larvae.
3. Prevent ingestion of raw or undercooked fish.
4. Institute effective rodent control program.
5. Prevent dogs and cats from eating rodents.
6. educate public about neccesity of cooking fish.
7. Institute proper fecal waste disposal system.
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Filariasis
Brugiu malayi,
Dirofiaria spp.(D. immitis, D. tenuis, D. repens), Lou loa,
Onchocerca spp.(O. volvulus, 0. cervicalis), Dipetalonema spp.(D.
perstans, D. streptocerca)
Human:
Most infections produce painful subcutaneous swellings.
Incubation period: 8-9 month prepatent period.
Case fatality rate: Low.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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Confirmatory tests:
1. microscopic examination of blood for presence of
microfilaria.
2. Also test paired sera for complement fixation,
hemagglutination and immunofluorescent antibodies.
3. Radiology for D. immitis infection.
Occurrence: worldwide.
Transmission: By many genera of mosquitoes.
CONTROL AND PREVENTION
1. Treat with diethylcarbamazine.
2. Institute vector control program.
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Thelaziasis
Thelazia spp.,
Human:
1. Conjunctivitis, photophobia, lacrimation.
2. Corneal scarring may follow prolonged infection.
Confirmatory tests:
1. Microscopic identification of parasite after removal from eye.
Occurrence: Worldwide.
Transmission:
Flies that feed on the lacrimal secretion of infected hosts serve as
intermediate hosts and vectors.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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CONTROL AND PREVENTION
2. Remove worm from conjunctival sac.
3. Education regarding method of transmission.
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Trichinosis
Trichinella spp.,
Human:
Ranges from asymptomatic to mild febrile reaction to myalgia,
diarrhea, ocular pain, palpebral edema, myocardial failure, CNS
disturbance, and death.
Incubation period: 5-15 days, average 10 days.
Case fatality rate: Low.
Confirmatory tests:
1. Paired sera for complement fixation, indirect fluorescent
antibody, ELISA
2. Muscle biopsy for microscopic identification of larvae.
Occurrence:
1. Worldwide.
2. Reservoir exists in rats, swine, dogs, cats, and many wild
animals.
Transmission: Ingestion of raw or undercooked meat containing
viable larvae
CONTROL AND PREVENTION
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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1. Treat with thiabendazole and corticosteroids.
2. Cook or freeze to kill larvae in all meat from potentially
infected sources (pork, pork products, bears, and seals)
before eating.
3. Sanitary disposal of garbage.
4. Cook all garbage fed to swine.
5. Rodent control.
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Cutaneous larva Migrans
Ancylostoma braziliense. ("larva currens")
Human:
a. Papules at site of entry.
b. Highly pruritic,
c. erythematous, serpentine lesions,
d. commonly accompanied by secondary bacterial infection
resulting from scratching.
Incubation period: 2-3 days.
Mortality rate: Self-limiting in several weeks to months.
Occurrence:
Most prevalent in areas with warm, moist climate and sandy soil.
Transmission:
a. Direct contact with filari form larvae in soil contaminated with
feces from dogs or cats.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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CONTROL AND PREVENTION
1. Treat with thiabendazole, antipruritics, and sedatives.
2. Antibiotics may be indicated to control secondary infection.
3. Protective clothing when working in contact with soil
potentially contaminated with dog or cat feces.
4. Periodioc anthelmintic treatment of dogs and cats.
5. Elimination of strays.
6. Prohibition of dogs and cats on playgrounds and beaches.
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Visceral larva Migrans
1. Toxocara canis,
2. Toxocara cati,
3. Baylisascaris procyonis,
4. Gnathostoma spinigerum
Human:
1. Usually mild.
2. Heavy infection may produce fever, cough, skin rash.
3. If eye is involved, it may simulate retinoblastoma with
strabismus and blindness.
Incubation period Weeks to months.
Case fatality rate: Low.
Confirmatory tests:
1. Paired sera for ELISA, complement fixation, indirect
hemagglutination.
2. Liver biopsy for microscopic identification of larvae.
Zoonoses 4th year 7-5-2017 Dr.Osamah Muwaffag
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Occurrence: Worldwide. Primarily a childhood disease.
CONTROL AND PREVENTION
1. Treat with diethylcarbamazine.
2. Personal hygiene.
3. Prevent contamination of soil with dog and cat feces.
4. Treat dogs and cats beginning at 3 weeks of age.
5. Cook meat, fish, and poultry before eating.
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