Leishmania Donovani

1
Leishmania Donovani

• A brief overview

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Prevalence

• Leishmaniasis currently infects 350 million men,
  women, and children in 88 countries around the
  world and there are three kinds
• Cutaneous
• Mucocutaneous
• Visceral
• Some estimate that 12 million people are
  presently infected

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Prevalence
Cutaneous Leishmaniasis
Visceral Leishmaniasis
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Leishmania throughout the ages

• Dates as far back as the 15th and 16th centuries
  with the Incas
• During Spanish colonization, seasonal workers
  would suffer from valley sickness or Andean
  sickness.
• Also known as white leprosy for its
  disfigurements of the face

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Leishmania throughout the ages

• Indian physicists called it kala azar, meaning
  black fever
• Pre-Incan pottery from Ecuador and Peru also show
  individuals with facial deformities and skin
  lesions

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How it was discovered

• 1756- Alexander Russell gives first clinical
  description of the disease after examining a
  Turkish patient. Called it the Aleppo boil
  after Aleppo, Syria.
• After it is cicatrised, it leaves an ugly scar,
  which remains through life, and for many months
  has a livid colour. When they are not irritated,
  they seldom give much pain.

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How it was discovered

• 1901-Leishman identified the organisms that
  caused dum-dum fever. This disease caused
  debility, fevers, anemia, muscular atrophy and
  splenomegaly. Leishman thought these were
  trypanosomes.
• 1903-Captain Donovan discovered that the
  organisms causing dum-dum fever were new.

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How it was discovered

• Major Ross discovered the link between the
  organisms that caused dum-dum fever and kala
  azar. He named them Leishmania donovani.

9
Leishmania in action

• Sudan
• In 1997, there was a 400 increase in cases over
  the previous year caused by the migration of
  seasonal workers and individuals moving to escape
  civil unrest
• Disease also migrated to Eritrea and Ethiopia

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Leishmania in action

• Brazil
• Has seen a large increase in cases since 1999.
• Drought, dwindling farm land, and famine causes
  people to move the to cities where little
  infrastructure and sanitation allows the disease
  to flourish
• Children under are the group with the greatest
  risk

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Leishmania in action

• Afghanistan
• War and civil unrest makes the disease hard to
  control.
• An epidemic in 2002 killed an estimated 100,000
  people in Kabul
• Returning refugees and other displaced persons
  have low levels of resistance to the disease

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Diagnosis

• Antigen detection in urine
• Dipsticks K39/K26
• For Visceral Leishmaniasis
• enzyme liked immunosorbent assay (ELISA)
• direct agglutination test (DAT)
• indirect fluorescent antibody test (IFAT)

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Treatment

• March 2002- 1st oral drug for visceral
  leishmaniasis registered (milefosine)
• currently used in India
• safe and effective ? up to 98 cure rate
• mild side-effects ? vomiting and diarrhea
• does not require refrigeration
• Other drugs- sitamaquine and aminosidine

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How we can help

• Facilitate early diagnosis and prompt treatment
• Control sandfly populations through insecticide
  spraying and the uses of bednets
• Provide health education
• Detect and contain epidemics in the early stages

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What helps the disease spread

• Poor sanitation
• the sandfly population breeds more frequently in
  places where sanitation is poor such as ruined
  buildings, dead animals, household rubbish, etc.
• Dense populations
• sandflies have a greater population to infect
• Mass migration of individuals
• The movements of individuals to new area
  introduces the disease to people who have no
  immunity to it

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What helps the disease spread

• Social stigmas of the disease
• People suffering from the disease are often left
  untreated and may be ostracized from their
  community
• Under-reporting of the disease to health
  organizations
• The true impact of the disease is not known
• Lack of medication
• Cannot properly control outbreaks

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Resources

• www.who.int/tdr/diseases/leishmaniasis/direction.h
  tm
• http//www.who.int/leishmaniasis/en/