The Piroplasms p' 166169

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The Piroplasms p. 166-169
Piroplasms are members of the Phylum Apicomplexa
that use ______________________________. Two are
of _____________________________but one species
does infect humans. 
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Babesia bigemina
  Causative agent of _____________________________
______________ of veterinary importance In
infected cattle, parasite causes massive
destruction of erythrocytes, resulting in
_________________________________________ - death
occurs in 1 week
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Babesia bigemina
  VECTOR - _________________________________
HISTORICAL NOTE - This was first protozoan
shown to
be vectored by an arthropod. Smith
and Kilbourne
in 1893 worked out the life cycle.
This finding lead
others trying to work out life
cycles of malaria,
kala azar, sleeping sickness,
etc. to consider
arthropods as vectors.
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Life Cycle of Babesia bigemina

• 1. An infected tick bites cattle releasing
  __________________________ into the cow
  bloodstream.
• 2. Sporozoite penetrates a rbc and becomes a
  _______________________.
• 3. Trophozoite undergoes binary fission - 2
  trophozoites often appear attached anteriorly
  (diagnostic!).
• 4. Rbc is destroyed and trophozoites reinvade
  new rbc's
• this asexual cycle continues
  
  
  indefinitely until the host dies.

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• 5. Feeding tick picks up rbc's with
  trophozoites.
• 6. Trophozoites penetrate cells of many organs
  and undergo schizogony to release
  __________________________.
• 7. Some merozoites enter the tick's ovaries and
  eggs are transmitted to the next generation of
  ticks by ________________________________.
• 8. Merozoites undergo schizogony in tick
  offspring and infective stage ____________________
  _________ are produced
• sporozoites migrate to the tick salivary glands
• transmitted to cattle with next tick bite.

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Babesia bigemina
PATHOLOGY - ____________________ _________________
_________________ - Older cattle are more
severely affected. - Symptoms loss of
appetite, fever,
listlessness, bloody urine - death
common  TREATMENT - Suramin Berenil - drugs
effective against Trypanosoma brucei are
effective against Babesia - reason is unknown
Trophozoites in cattle rbcs
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Babesia bigemina
DISTRIBUTION - occurs throughout cattle-growing
areas of Africa, South America, Europe, and
Australia In U.S. ?
Trophozoites in cattle rbcs
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Babesia canis
Infects dogs throughout the world   VECTOR -
 (Rhipicephalus sanguineus)   PATHOLOGY -
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Babesia microti
This species normally occurs in
________________________________, but recent
cases of it have been reported in
humans. Causes _____________________________
____________- reported in Massachusetts (first
report in 1975), New York, Rhode Island, and
Wisconsin -2 cases in Wisconsin were
identified in 1983 - See following report from
Wisconsin Epidemiology Bulletin.

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Babesia microti

VECTOR - ______________________________ -
larvae and nymphs feed on meadow voles to pick up
infection - they then bite humans to transmit
the disease - no transovarian transmission
(dont confuse babesiosis with Lyme disease,
a bacterial disease, also
transmitted by deer ticks)
meadow vole Human deer tick
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trophozoite
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Babesia microti
PATHOLOGY - ______________________________________
_____________ Immunocompromised persons are at
greatest risk __________________________________
______________________ __________________________
______________________________ TREATMENT  
Babesia microti in human rbcs
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The Coccidians Chapter 8

• Coccidians are members of the Phylum Apicomplexa
  that __________________________________(not
  rbcs) of the vertebrate host.
• There are several species of medical and
  veterinary importance.
• Cryptosporidium spp.
• Several species of Cryptosporidium are well known
  as intestinal parasites of domestic animals
  (sheep, cattle, chickens, turkeys) causing the
  disease __________________________________________
  __.
• 3 species are now recognized
• Human species Cryptosporidium hominis
  (anthroponosis)
• Cattle species
• Cryptosporidium parvum (zoonosis) affects
  humans and other livestock
• Cryptosporidium andersoni - in cattle only (not
  known if zoonotic)
• research at UWEC found 38 infection rate of C.
  parvum in dairy calves
• - outbreaks occur throughout the U.S.

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Cryptosporidium

• Cryptosporidium was recognized as_________________
  ______________
• recognized in AIDS patients in 1976
• ______________ of AIDS patients reported to CDC
  have Cryptosporidium
•  

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Cryptosporidium

• This parasite has been incriminated in large
  outbreak of diarrhea in humans in
  ______________________________________________
• associated with contamination of surface water
  in Lake Michigan used for drinking
• due to Cryptosporidium ____________________
  likely from a sewer contamination of drinking
  water
• one of 2 water purification plants was
  contaminated, and treated water showed high
  turbidity levels.
• numbers of cases
• cost -
•  

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Life Cycle of Cryptosporidium
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Cryptosporidium parvum
_____________ on the surface of small intestinal
cells
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Oocysts of Cryptosporidium
Each oocyst contains 4 sporozoites that attach to
surface of small intestinal cells
unstained
acid red stain Oocysts from cattle feces
oocysts are 4-5 µm in diameter
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Cryptosporidium

• MOST Cases of Cryptosporidiosis are a
  ______________________________as human infections
  arise from infections in young cattle
• oocysts in cattle feces typically contaminate
  surface water used for drinking
•  
• PATHOLOGY
•  
• (1) In immunocompetent (normal) humans -
•  
• (2) In AIDS patients and immunocompromised
  persons -
•  
• TREATMENT -
•  
•  

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Cyclospora

• First human cases reported in 1979
• Major outbreak of Cyclospora cayetanensis
  occurred in New York in 1996
• 1400 cases of diarrhea reported
• cause ?
• Several other cases have implicated
  _______________________________
• __________________________________________________
  ____
• these have been exposed to fecal
  contamination

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Cyclospora

• LIFE CYCLE is similar to Cryptosporidium
• oocysts are the infective and diagnostic stage
  size is ________µm in diameter (larger that
  Cryptosporidium)
• 4 sporozoites are released from each oocyst and
  penetrate cells of the small intestine -
  _____________________ is preferred area
• parasites inside intestinal cells

comparison of oocysts of Cryptosporidium and
Cyclospora
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Cyclospora

• PATHOLOGY
• (1) in immunocompetent persons
  ____________________ occurs
• Symptoms usually occur in a week
• Diarrhea lasts a few days or may persist for up
  to 6 weeks
• Disease is self-limiting
• (2) in immunocompromised people diarrhea is
  more severe and may last several months

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Isospora

• Isospora belli is parasitic in the
  ______________________________________
•  
• Disease is primarily __________________________
  cases in the U.S. are rare.
•  
• LIFE CYCLE is similar to Cryptosporidium
• Trophozoites, merozoites, gametocytes
  
  occur in the cytoplasm of small intestinal cells
  
  (not on surface like Cryptosporidium)
• Oocysts (20 -30 µm long) are released
  in
  feces (diagnostic)
• Oocysts are infective to new human
  
  host via human fecal contamination.
•  
•  

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Isospora life cycle
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Isospora

• PATHOLOGY
• (1) in immunocompetent individuals -
  some are asymptomatic and others
  develop a ___________________________ with
  abdominal pain and nausea that lasts about a
  week (mimics _____________ and may be
  underreported)
•  
• (2) in immunocompromised individuals -
  there is a chronic off and on
• diarrhea that lasts from 1 month to
  years
• invasion and destruction of small intestinal
  cells causes diarrhea, abdominal pain, and nausea
•  
• __________ of AIDS patients reported to CDC had
  Isospora
•  
• Specific treatment is available but recurrences
  are common.

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Eimeria tenella and Eimeria bovis
Many species of Eimeria infect domestic animals
and are of veterinary importance None infect
humans. Two important species are Eimeria
tenella - in ________________________ Eimeria
bovis - in _________________________ LIFE CYCLE
similar to that of other
coccidians, but
Eimera tenella and
Eimeria bovis
infect cells of the

__________________________________ Oocysts are
released in the feces of
infected
animals and are ingested to
cause new
infections.
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Eimeria tenella and Eimeria bovis
PATHOLOGY E. tenella - __________________________
___is affected causing fatal bloody diarrhea
- highest mortality in young chickens -
costs poultry farmers millions of dollars each
year in losses E. bovis - cells of
________________________________ are destroyed
causing a fatal bloody diarrhea in cattle All
commercial feeds now contain anticoccidial drugs
to prevent the disease. Again, costly to farmers.
Once the disease is established, there is no
effective treatment.  
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Toxoplasma gondii
This coccidian parasite is the causative agent of
_______________________ Life cycle is unusual in
that it involves 2 hosts 1. Cats are the only
definitive hosts 2. Some _______________species
of birds and mammals may serve as intermediate
hosts. 3. Humans are ___________________________
___________ Toxoplasmosis is commonly
transmitted from cats to humans thus, it is a
______________________________________. Parasite
has cosmopolitan distribution - recent cases have
been identified in Wisconsin - is both ENZOOTIC
AND ENDEMIC in Wisconsin.
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Life Cycle of Toxoplasma gondii
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Life Cycle of Toxoplasma gondii
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Toxoplasma gondii
NORMAL MAINTENANCE CYCLE of Toxoplasma in
nature _________________definitive host
___________________________intermediate hosts
BEHAVIOR CHANGE A recent study indicates that
the Toxoplasma parasite
can alter the behavior of its
rodent host.
Oxford scientists discovered that
the minds of the infected rats have been subtly
altered. They demonstrated that healthy rats
will prudently avoid areas that have been doused
with cat urine.

However, it turns out that Toxoplasma-ridden
rats show no such reaction. In fact, some of the
infected rats actually seek out the cat
urine-marked areas again and again. The parasite
alters the mind (and thus the behavior) of the
rat for its own benefit.
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Toxoplasma gondii
  3 METHODS OF HUMAN INFECTION

• 1. Ingestion of __________________________ via
  cat fecal contamination (from sandboxes,
  changing
  cat litter, etc.)
• Ingestion of ___________________________ in
  uncooked meat (pork, lamb, beef, chicken, turkey,
  wild animals)
• 3. Transplacental transmission of
  
  __________________________________in an infected
  mother across placenta to infect fetus resulting
  in _____________________________

Toxoplasma oocysts in cat feces
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Pathology of Toxoplasma gondii

• In cats - infection is asymptomatic in adult cats
  
• acute infections caused by _______________________
  ______________ results in numerous intestinal
  lesions can kill kittens
• In humans
• ACUTE INFECTIONS - associated with
  ______________________________
• __________________________________________________
  _____________
• causes ___________________________________________
  ______________
• Symptoms are fever, headache, muscle pain,
  swollen lymph glands

Tachyzoites occur in groups in any nucleated body
cell
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Pathology of Toxoplasma gondii

• CHRONIC INFECTIONS - associated with
  ________________________________.
• is often asymptomatic.
• some infections may develop ___________________
  ___________________
• AIDS infections result in severe
  ___________________________________ (paralysis
  death), retinitis, and/or myocarditis.
• T. gondii has been identified in _______ of
  AIDS cases reported to CDC.

Bradyzoites occur in a circular mass in body
cells organs commonly infected are the liver,
brain, retina, and heart
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Pathology of Toxoplasma gondii

• CONGENITAL INFECTIONS can have 3 different
  pathological effects
• may be _________________________________
• may cause serious ______________________________
  _____
• may result in __________________________________
  ____________
• Pathology is greatest if the disease is
  contracted during embryonic development (i.e. the
  first 8 weeks after conception). Woman may not
  even know she is pregnant during this time.
• Common defects include
• ______________________________________
• ______________________________________
• ______________________________________

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Pathology of Toxoplasma gondii
DIAGNOSIS TREATMENT
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PREVENTION A WOMEN WHO KNOWS SHE IS
___________________________ SHOULD NEVER HANDLE
THE LITTERBOX OR CLEAN UP AFTER CATS. IT IS
BEST NOT TO HAVE A CAT DURING CHILD-BEARING
YEARS. SO GET RID OF THE ________________________
___! Recent article http//www.cnn.com/2005/HEA
LTH/02/09/pregnancy.catbox.ap/index.html
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Pneumocystis jirovecii (formerly Pneumocystis
carinii name in text)

• This parasite was originally described as a
  member of the Phylum Apicomplexa
• it is now considered to be a ___________________
  ___, most closely related to a group of
  __________________________
• however, it shows many protozoan characteristics
• Species name was changed in 2005 -
• P. jirovecii is now human species
  
  P. carinii is a rat species
• Interesting it was first identified by
  
  ____________________________
  who
  discovered it when working on
  the
  life cycle of ________________________
  
  in 1909

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Pneumocystis jirovecii (formerly Pneumocystis
carinii name in text)
Parasites occurs in _____________________ _______
_____________________________ Two stages
-__________________________ ______________________
______________

- have been identified in infected

lung tissue.
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Pneumocystis jirovecii

• PATHOLOGY
• 1. Parasites are _______________________________
  in healthy persons. (Recent study reported that
  gt75 of children over age 4 are seropositive.)
• In AIDS patients, the parasite causes severe
  _______________________________________________
• - Symptoms are _________________________________
  _______________________________________________
• - This complication often is a major
  
  cause of death in AIDS patients.
• - Pneumocystis occurs in _____________
  of patients
  having AIDS
•  

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Pneumocystis jirovecii
TRANSMISSION - ___________________________________
_ and by __________________________________ from
one person to another.   DIAGNOSIS chest X-ray
with pulmonary infiltration ID organism in
bronchial washings or lung biopsy TREATMENT a
variety of ___________________________________

are now available to AIDS patients  

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The End of the Protozoa