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Impact
Leishmaniasis is a parasitic disease transmitted by the bite of a sandfly that
is infected with Leishmania parasites. Currently 350 million people in 88
countries around the world are threatened, and 12 million people are affected by
leishmaniasis. Of the 1.5 – 2 million new cases of leishmaniasis estimated to
occur annually, most occur in the tropics and subtropics, including the Middle
East, although American soldiers stationed in the Middle East are returning to
the U.S. infected with the disease. Leishmaniasis is considered a threat in
southwestern Europe, such as Spain, Italy, France, and Portugal. The geographic
spread is due to factors related to development, including massive rural-urban
migration and agro-industrial projects that bring non-immune urban dwellers into
endemic rural areas. Manmade projects with environmental impact, like wells,
irrigation systems and dams, as well as deforestation, also contribute to the
spread of leishmaniasis.
Symptoms
With the bite of an infected sandfly, Leishmania parasites are passed
from one infected animal or human to others. Leishmaniasis is a spectrum of
diseases, each distinctly manifested and all with potentially devastating
consequences – disfigurement, damage to internal organs, death. Depending on the
species of the infecting parasite, the spleen, liver, bone marrow, mucous
membranes, and/or skin may be attacked. Leishmania donovani, the most
dangerous of these, causes Kala azar, or visceral leishmaniasis, characterized
by fever, severe weight loss and anemia. If left untreated, visceral
leishmaniasis can lead to death.
SBRI's Role
In collaboration with researchers in Brazil, Canada, England, France, Germany,
Sweden, India and the U.S., SBRI has made progress in unraveling the mysteries
of this and other diseases caused by parasites of the Trypanosomatidae family to
which Leishmania belongs. The draft sequencing of the genome of the
Leishmania major Friedlin parasite is now complete, opening the doorway for
new drugs and therapeutics to follow. Research at SBRI has led to identification
of an unusual arrangement of genes in these complex organisms. After a
three-year effort, SBRI developed a way to turn genes on and off, allowing the
study of these essential roles specific Leishmania genes play in causing
disease. These and other discoveries are providing important clues to how gene
structure and function are linked to critical cellular functions.
Kenneth D. Stuart, Ph.D., investigates the biological mechanisms of parasites in order to identify new targets for drugs, vaccines, and diagnostics. The lab is sequencing the
Leishmania genome and identifying gene that are important to disease.
Marilyn Parsons, Ph.D., explores cellular and molecular life functions in order to find key differences between the host and parasite.
Peter J. Myler, Ph.D., applies genomics and bioinformatics technology to understand regulation of gene expression and function in single-celled parasites.
Links
WHO
Leishmania and Leishmania/HIV co-infection Fact Sheet
WHO
Leishmaniasis World Health Organization
CDC
Leishmaniasis Center for Disease Control and Prevention
Leishmania: After the Genome (book) In this book, internationally
recognized Leishmania experts, including Peter Myler, critically review
the most important aspects of current Leishmania research, providing the
first coherent picture of the organism's molecular and cellular biology since
the publication of the genome sequence. Chapters are written from a molecular
and genomic perspective and discuss in depth Leishmania-specific aspects
of trypanosomatid biology and pathology.
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