Piroplasms zPiroplasms or Piroplasmida are an order of the Apicomplexa zThey are very small parasites of mammals and ticks zThere are two genera which.
Post on 22-Dec-2015
216 Views
Preview:
Transcript
Piroplasms
Piroplasms or Piroplasmida are an order of the Apicomplexa
They are very small parasites of mammals and ticks
There are two genera which cause import disease in livestock (and occasionally in humans): Babesia & Theileria
Babesia
Numerous species which cause malaria like disease in wide variety of animals
Babesia
There are >100 species of this intracellular parasite. The disease caused by Babesia known as Babesiosis The disease distribute all over the world where there is
tick available. Babesia microti is the predominant human pathogen,
endemic to the NE and Midwest.
Natural parasite reservoir is rodents Its common among dogs, cattle , goats, sheep, horses and
rodents Carried by the hard-bodied Ixodes tick. more severe in patients who are immunosuppressed,
splenectomized, and/or elderly
There are 17 species that infect domestic & wild animals
all over the world.
The parasites reproduce by binary fission inside the
R.B.Cs, after transmission with the tick saliva.
Babesia
• Transfusion of infected
blood
• Transplacentally• Tick bite
Transmission
Babesia microtiB. divergensB. duncani
Morphology
•Easily misdiagnosed as Plasmodium in areas high in Malaria prevalence due to its “ring shape”
•Variation in shape and size
•Do not produce pigment
Intraerythrocytic Babesia microti
Babesia microti
Hosts
Definitive host: Ixodes spp.Intermediate host: White-footed
mouse and other rodents, human
Babesia life cycle
Numerous erythrocytes are infected with the predominantly ring or pear-shaped form of Babesia microti.
Pleomorphic rings with 1-3 chromotin dots per parasite. 3 dots is unique for Babesia.
The Famous Maltese Cross
• Presence of 4 daughter merozoites in a tetrad is pathomnemonic.
• Never seen in malaria.
Multiply Infected RBCs
RBCs can be infected with multiple organisms at the same time. Up to 12 parasites may infect a single RBC.
Plasmodium has up to 3 parasites/RBC.
Other Sightings
•Syncytium of extracellular parasites
•more common in Babesia infections
Babesiosis
Babesiosis (piroplasmosis) is a hemolytic disease similar to malaria but without an exoerythrocytic cycle.
Disease caused by B. divergens can be severe, even fatal, in splenectomized and debilitated patients (Most patients are older than 50 years of age).
B. microti causes a self-limiting febrile disease characterized by fatigue and anorexia.
Clinical Symptoms
Ranges from asymptomatic infection to fatal illness (rare)
More severe infection tends to occur in immunnocompromised, elderly, and the very young.
The extreme end of the spectrum is often described as a malaria-like infection; symptoms may include
Fever, sweating, chills, headache, anemia, jaundice, malaise, haemoglobinuria & Weakness.
Diagnosis
Microscopic examination: thick and thin blood smears stained with Giesma
Antibody detection: detects even low levels of parasitic invasion Indirect fluorescent antibody test (IFA) detects
antibodies (IgM & IgG) of patients with B. microti infection
Recommended only if low levels of parasitemia or blood smear is inconclusive
Diagnosis can be derived from molecular techniques, such as PCR
Treatment
Clindamycin*: antibiotic with little or no side effects
Quinine or Atovaquone*: antiparasiticAzithromycin*: antibiotic, some side
effectsClindamycin combined with Quinine is
treatment of choice
*FDA approved, but considered investigational
top related