The Piroplasms – p. 166-169 Piroplasms are members of the Phylum Apicomplexa that use ______________________________. Two are of _____________________________but one species does infect humans. Babesia bigemina
Piroplasms are members of the Phylum Apicomplexa that use ______________________________.
Two are of _____________________________but one species does infect humans.
Causative agent of ___________________________________________ – of veterinary importance
In infected cattle, parasite causes massive destruction of erythrocytes, resulting in _________________________________________ - death occurs in 1 week
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.
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 rbc’s
DISTRIBUTION - occurs throughout cattle-growing areas of Africa, South America, Europe, and Australia
In U.S. ?
Trophozoites in cattle rbc’s
Infects dogs throughout the world
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.
VECTOR - ______________________________
- larvae and nymphs feed on meadow voles to pick up infection
- they then bite humans to transmit the disease
- no transovarian transmission
(don’t confuse babesiosis with Lyme disease, a bacterial disease, also transmitted by deer ticks)
PATHOLOGY - ___________________________________________________
Immunocompromised persons are at greatest risk:
Babesia microti in human rbc’s
_____________ on the surface of small intestinal cells
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
comparison of oocysts of Cryptosporidium and Cyclospora
Isospora belli is parasitic in the ______________________________________
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.
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.
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.
NORMAL MAINTENANCE CYCLE - ______________________________ relationship maintains toxoplasmosis in nature.
3 METHODS OF HUMAN INFECTION:
Toxoplasma oocysts in cat feces
Tachyzoites occur in groups in any nucleated body cell
Bradyzoites occur in a circular mass in body cells – organs commonly infected are the liver, brain, retina, and heart
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 ___________________________!
Parasites occurs in _____________________
Two stages -__________________________
____________________________________ - have been identified in infected lung tissue.
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