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