Transcript What is Leishmaniasis? - Alberta Vein to Vein Society

Leishmaniasis
Thomas Fourie MD
M. Taher Shabani-Rad MD
CLS, Division of Hematopathology
Leishmaniasis
Chagas
Disease
HLH
Transfusion
What is Leishmaniasis?
• Leishmaniasis is caused by infection with a protozoan
parasite that is spread by the bite of infected sandflies
• Protozoans are historically defined as a single-celled
organisms with animal-like behaviour, such as
motility and predation (attacking)
Two forms of Leishmaniasis
Amastigote of Leishmania
The life cycle of Leishmania
Sand fly
At least 93 sandfly species are proven or probable
vectors worldwide.
World distribution
of Visceral Leishmaniasis
Canada is not highlighted on leishmana map and No leishmaniasis had been previously reported in Alberta
What is HLH?
• Hemophagocytic LymphoHistiocytosis
• Immunologic disorder
• Over production and –activation of T cells and
histiocytes
• Phagocytosis of normal hematopoietic cells by
histiocytes
Primary/inherited HLH
• Rare – 1 case per million children
• Primary HLH is caused by an inherited
problem with the immune system
• 5 genes have been identified, including the
perforin gene
• Onset of the disease occurs in first year of
life in 70% of cases
Secondary/reactive HLH
• No family history
• No genetic abnormalities
• Triggers:
Infection - Viral, Bacterial, Protozoan, Fungi
Malignancy – T cell lymphoma
Auto-immune - SLE
Visceral
Leishmaniasis
• Enlarged liver or spleen
• Fever
• Anemia
HLH
• Enlarged liver or spleen
• Fever
• Cytopenias
Visceral Leishmaniasis
(kala-azar)
HLH
• Mortality rate of more than 90%
within 2 years if left untreated
• Mortality rate of 100% over
the course of 2 months if
left untreated
• Antibiotics including
Amphotericin B
• Cytotoxic chemotherapy to
supress the immune system
Case
2 year old child
Diagnosed with HLH
Bone marrow: Routine pre-BMT Assessment for Cord
Stem Cell Transplant for HLH
It is difficult to differentiate leishmania bodies from platelet and cellular debris (Double dot nucleus)
Presence of leishman bodies in BM H&E sections are very diagnostic of BM leishmaniosis
(Platelets are not seen in BM biopsy sections)
BM performed 6 months earlier
Canadian born child
• No sandfly of the type that transmit
Leishmaniasis in North America
• Leishmaniasis does not exist in
Alberta
• History of blood transfusions
Biting midge, Sand fly or Punkies
Could this have been transmitted by a
blood transfusion?
• Cryptic infection in blood donors from endemic
areas
• Cases of transfusion transmitted Leishmaniasis have
been reported in non-endemic areas
• Most of these cases involved infants or children
Yes
CBS screening for Leishmaniasis
• Ask donors if they ever had Leishmaniasis
• If yes – deferred indefinitely
• Lab test?
• Not really
Chagas disease (Trypanosomiasis)
Also transmitted by an insect
Mexico, Central- and South America
Chagas disease
• Donors from endemic areas are tested
• Abbott Chagas antibody test
• Some cross reactivity with Leishmaniasis
• Not reliable for exclusion of Leishmaniasis
What was the source of infection?
• Travel history
• Family visited Albania after the child's birth
• Albania is endemic for Leishmaniasis
• Mediterranean Visceral Leishmaniasis affects
primarily children or immunocompromised
individuals
• It is known to occur since 1938, typically as a
childhood disease in Albania
• Developing country with suboptimal disease specific
surveillance
• Newborns can be infected, even with asymptomatic
mother
Conclusion (1)
• HLH can occur in cases with Leishmaniasias
• Leishmaniasis can be difficult to diagnose if you
are not looking for it
• Leishmania parasites can be mistaken for
phagocytosed platelets or cellular debris
Conclusion (2)
• Leishmaniasis can be transmitted by
transfused blood of asymptomatic, infected
individuals
• Very rare - only 11 reports of transfusion
transmitted Leishmaniasis worldwide
• All reports were from Asia and Europe
• 9 of the 11 cases occurred in children less than
6 years of age
Conclusion (3)
• Chagas antibody test can be “false” positive in a
patient with Leishmaniasis
• PCR technology can be used for mass screening
of donor blood samples for Leishmaniasis
• In Canada the cost outweigh the benefit
• Currently donors are deferred only if they where
diagnosed with Leishmaniasis
• Transmission of Leishmaniasis by an
asymptomatic individual is a possibility, but very
unlikely