Dr.Waqas Nawaz PMAS arid agriculture univrsity rawalpindi

1. GENERAL PARASITOLOGY AND
PROTOZOLOGY
PRESENTATION
TOPIC: PARASITIC ZOONOSIS
SUBMITTED TO: DR.MURTAZ UL
HASSAN
SUBMITTED BY : AQEEL AHMAD (07-ARID-
1690)
BADAR HUSSAIN (07-
ARID-1705)
SAHIL JOHN (07-
ARID-1721)
MUHAMMAD HAISEM (07-ARID-

2. ZOONOSIS:
INTRODUCTION:
The World Health Organization defines Zoonoses (Zoonosis,
sing.) as "Those diseases and infections which are naturally
transmitted between vertebrate animals and man".
CLASSIFICATION:
Zoonoses can be classified in many ways:
According to the mechanism of transmission
 Anthropozoonoses: Infections transmitted to man from lower
vertebrates (ex: rabies, toxoplasmosis)
 Zooanthropozoonoses: Infections transmitted from man to
animals (ex: diphteria, amebiosis)
 Amphixenoses: Infections maintained in both man and lower
vertebrates, and may be naturally transmitted in either direction
(ex: Staphilococcus, mycobacteria)

3. CONTINUED…………..
According to the life cycle
Direct Zoonoses: Transmitted from infected vertebrate host to a
susceptible vertebrate host by direct contact or by a mechanical
vector. No developmental change or propagation of the organism
occurs during the transmission (ex: Rabies, trichinosis, and
brucellosis)
Cyclozoonoses: Requires more than one vertebrate host, but no
invertebrate host. (ex: Echinococcosis, human taeniasis and
Pentastoma infections)
Metazoonoses: Agent multiplies, develops, or both in an invertebrate
host before transmission to a vertebrate host is possible. (This means
that a definite prepatent or incubation period must be completed
before transmission.) (ex: Arboviruses, plague, and schistosomiasis)

4. CONTINUED…………..
Saprozoonoses: To transmit these infections a non-animal
development site or reservoir is required, such as food
plants, soil, or other organic material. (ex: larva migrans and
some of the mycotic diseases)
According to the etiology (mostly used)
Bacterial zoonoses: Botulism, tuberculosis
Viral zoonoses: Rabies, Hepatit A virus
Fungal zoonoses: Aspergillosis, actinomycosis
Protosoal zoonoses: Anaplasmosis, babesiosis, malaira
Helmintic zoonoses: Trichinosis, echinococosis, taeniasis

5. TOXOPLASMOSIS:
Causative agent : Toxoplasma gondii
A coccidium belonging to phylum
Apicomplexa
Toxon = arc; Plastos = form. One stage
in the life cycle is arc- shaped.
The species name is derived from the
host in which the parasites was first
described: Ctenodactylus gundi = small
African rodent.
HOST: mammals. Especially cats,
food animals ,birds and humans.
Mode of transmission: ingestion of
oocysts shed in feces of infected cats
or found in raw meat and milk.

7. Pathology:
Trachyzoite multiplication results in focal necrosis, the most
characteristic lesion of toxoplasmosis. Inflammation usually
follows necrosis. Pneumonitis is the predominant lesion in
fatal toxoplasmosis in cats and dogs; placental necrosis with
white flecks or multiple white, chalky, necrotic nodules and
associated abortion predominate in sheep and goats.
Histologcially, this necrosis is confined to the cotyledons
where individual and small group of tachyzoites are often
difficult to recognize among degenerating host cells.
Encephalomyelitis is the predominant lesion in sheep.
Diagnosis:
Diagnosis of Toxoplasma is performed at postmortem by
identification of organisms in infected tissue. Diagnosis in
live animals is aided by serologic tests and in cat by fecal
examination.

8. Prevention and Control:
The following preventative measures apply to all persons, but
because toxoplasmosis is most severe in the prenatal period, they
should be emphasized for pregnant women and for young children.
1. Avoid contamination with oocysts from cat feces by:
a. Feeding cats dry, canned or thorougly cooked food
b. Preventing cats from hunting birds and rodents
c. Emptying litter boxes daily, before oocysts sporulate
d. Wearing gloves or thoroughly washing hands after working in
the garden or with soil, and before eating or touching the face
e. Covering children’s sandboxes when not in use
f. Preventing aerosols in the laboratory during centrifugation of
potentially infected biological samples
g. Boiling drinking water from streams, ponds, or lakes
frequented by cats
2. Avoid ingestion of tissue cysts by cooking meat to over 660 C and
washing hands after handling raw meat.

9. The following preventative measures apply to farms and
other animal-rearing facilities. Avoid contamination of
feed or water with oocysts in cat feces by:
1. Using rodenticides and traps to prevent cats from
hunting rodents
2. covering, closing or locking feed-storage facilities to
prevent cats from entering and defecating
3. Promptly removing cat feces from building stalls or
cages; and flushing, burning, or burying them to destroy
oocysts
4. Providing adequate dry, canned, or thoroughly
cooked food and separate water to prevent cats from
sharing facilities used by other animals.

10. SARCOCYSTIS :
Causative agent: Sarcosystis
suihominis.
S. hominis
A coccidium belonging to phylum
Apicomplexa
Humans may become infected by two
species, S.hominis and S.suishominis
HOST: man, cattle and swine
Mode of transmission: ingestion of
raw pork or beef; ingestion of feces.
Ingestion of raw beef ; ingestion of
feces.

11. LIFE CYCLE:

13. Pathology
Some species of Sarcocystis are pathogenic to the herbivore intermediate
host. Acute lesions characterized by hemorrhage, edema, and necrosis
are associated with the maturation of second generation meronts.
Macroscopic lesions observed postmortem may include generalized
serous atrophy of fat, excessive yellowish fluid in all body cavities, watery
blood, petechical hemorrhage in the heart and pericardium, serosa of the
gastrointestinal tract and urinary bladder, edema and hemorrhage of
lymph nodes, and alternate pale and dark striping or mottling of skeletal
muscles. Microscopically, hemorrhage may be seen in all organs, and
mononuclear cell infiltration into the perivascular tissues of the hear,
skeletal muscles, lung, liver, and kidney may be mild to severe.
Regenerative changes are most often associated with the myocardium.
Chronic lesions charactgerized by muscle atrophy and myositis are
associated with mature saccocysts. Specific macroscopic lesions may not
always be seen postmortem. Microscopic lesions may include myositis
and myocarditis. Most definitive hosts are clinically unaffected by
Sarcocystis infection.

14. Diagnosis:
EXAMINATION OF feces
Serologic tests
Meat inspection
CONTROL:
Cattle or swine should be prevented from ingesting
human feces and humans should avoid eating raw
or undercooked meat.