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
• Human infect during cattle (B. bovis) rodent (B. microti)
• 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, in Iraq there are 4 species
that infect domestic animal and they are as follows:
B. bigemina
Cattel
B. motasi
Sheep
B. equi
Horses
B. Caballi
Horses
The parasites reproduce by binary fission inside the
R.B.Cs, after transmission with the tick saliva.
Transmission
• Tick bite
• Transpalcental
• Transfusion of
infected blood
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.
High Power
• Ring shaped trophozites
• White eccentric “food
• The intraerythrocytic
vacuole” in a ring form.
trophozoites multiply by
• Very transient stage in
binary fission or
Malaria. Very rarely seen.
schizogony, forming two to
four separate merozoites. .
The Famous Maltese Cross
• Presence of 4 daughter merozoites in a tetrad is
pathomnemonic.
• However, rarely seen.
• 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
• Diagnosis is based on clinical suspicion and history of
exposure.
• Thick and thin smears remain most clinically used
• However, it is necessary to examine 200 to 300 oil
immersion fields before declaring a specimen
negative.
• Various PCR detection assays are available for
detection of B microtic and other species.
• More sensitive but also more time consuming and
expensive.
• Indirect fluorescent antibody test can also be used as
a confirmatory test.
Control and prevention
1. One should avoid tick exposure and, if bitten,
remove the tick from the skin immediately.
2. Treatment of infected animals with available
drugs .
3. Use of the Acaricides regularly & periodically
in the endemic area.