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.

• Transfusion of infected

blood

• Transpalcental• Tick bite

Transmission

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• The intraerythrocytic

trophozoites multiply by binary fission or schizogony, forming two to four separate merozoites. .

• White eccentric “food vacuole” in a ring form.

• Very transient stage in Malaria. Very rarely seen.

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.