SARS Update

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Collaborative Course on Infectious
Diseases January 2008
LECTURE 6 Leishmaniasis in Brazil
Jeffrey Jon Shaw jayusp_at_hotmail.com
Harvard School of Public Health (HSPH) Faculdade
de Ciências Médicas da Santa Casa de São Paulo
Brazil Studies Program, DRCLAS, Harvard
University
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Objectives

• Describe the distribution of leishmaniasis in
  Brazil
• Describe the transmission cycles of the most
  important species
• Describe consequences of infection
• Show how changes in the environment are altering
  the distribution of the different species found
  in man
• Discuss the difficulty of controlling the disease

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Possible lines of discussion

• What is the major epidemiological difference
  between leishmaniasis and malaria?
• Should leishmaniasis be considered a single
  disease entity?
• Can visceral leishmaniasis be controlled
• Can cutaneous leishmaniasis be controlled?
• What is the biggest leishmaniasis problem facing
  the Brazilian authorities?
• Dogs play an important role as reservoirs of
  leishmaniasis in various parts of the world
  What should be done with them? Should they be
  treated?
• What are the major epidemiological factors
  associated with epidemic visceral leishmaniasis?
• What are the potential public health dangers of
  so many sub-clinical cases?

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Leishmaniasis is considered to be endemic in 81
countries

• Most are tropical and subtropical countries
• 60 are classified as developing countries

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Cutaneous Leishmaniasis

• Number of Cases
• 1 - 1.5 million per year
• Origin
• 90 from Afghanistan, Brazil, Iran, Saudi
  Arabia Syria

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Regions of high endemicity for cutaneous
leishmaniasis
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Average density of cases of tegumentary
leishmaniasis, by municipality, Brazil 1994 to
1999 ( cases per Km2 )
Source FUNASA/CENEPI/CGVEP/COVEV
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Visceral Leishmaniasis

• Number of cases
• 500,000 per year
• Origin
• 90 from Bangladesh,
• India, Nepal, and Sudan

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Regions of high endemicity for visceral
leishmaniasis
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Increase of clinical cases and severe symptoms
related to HIV infections

• 34 countries reporting leishmania / HIV
  co-infection worldwide.

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Vector sand fly (Psychodidae Phlebotominae)

• Different species involved depending on the
  species of parasites.

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Parasite - Two forms

• In the mammalian host intracellular amastigotes
• Spread to uninfected cells of the host after
  primary infection
• Infective form for the vector
• In the sand fly (vector) extra cellular
  promastigotes
• Transmitted by the bite of the vector to the
  mammalian host

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Leishmaniasis in Brazil

• Cutaneous disease
• Caused by 8 named species
• In 2006, a total of 22,264 cases were registered
• 20,000 - 35,000 per year during the last 10 years
• The distribution of cases is changing

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Leishmaniasis in Brazil

• Visceral disease
• Caused by 1 named species
• In 2006 a total of 3,433 cases were registered
• 1,500 - 5,000 per year during the last 10 years
• The disease is becoming endemic in new regions
• The disease is invading urban areas

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Leishmanial Infections in man

• Incubation after bite (7-14 days)
• Clinical Symptoms
• Asymptomatic
• Acute - visceral disease fever, weight loss,
  hepatosplenamegaly
• Acute cutaneous disease ulcer or closed lesion
  at site of sand fly bite
• Secondary complications cutaneous metastasis
  resulting in secondary lesions after primary
  lesion develops years after cure - mucosal or
  disseminated cutaneous lesions

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Principal Difficulties facing Control Measures in
Brazil

• The different forms of leishmaniasis are zoonosis
  controlling infected animal populations is
  unfeasible
• The breeding sites of the different vectors are
  unknown making vector control extremely difficult
• The scale of the problem is not matched with the
  funds available

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References

• Grimaldi, G., Jr., David, J.R., MacMahon-Pratt,
  D., 1987, Identification and distribution of New
  World Leishmania species characterized by
  serodeme analysis using monoclonal antibodies.
  American Journal of Tropical Medicine and Hygiene
  36, 270-287.
• Shaw, J.J., Lainson, R., 1987, Ecology and
  epidemiology New World, In Peters, W.,
  Killick-Kendrick, R. (Eds.) The Leishmaniases in
  Biology and Medicine Volume I Biology and
  Epidemiology. Academic Press Inc, London, pp.
  291-363.
• Lainson, R., Shaw, J.J., Silveira, F.T., de
  Souza, A.A., Braga, R.R., Ishikawa, E.A., 1994,
  The dermal leishmaniases of Brazil, with special
  reference to the eco- epidemiology of the disease
  in Amazonia. Memórias do Instituto Oswaldo Cruz
  89, 435-443.
• Shaw, J.J., 1994, Taxonomy of the genus
  Leishmania present and future trends and their
  implications. Memórias do Instituto Oswaldo Cruz
  89, 471-478.
• Cupolillo, E., Momen, H., Grimaldi, G., Jr.,
  1998, Genetic diversity in natural populations of
  New World Leishmania. Memórias do Instituto
  Oswaldo Cruz 93, 663-668.
• Shaw, J.J., 2002, New World Leishmaniasis the
  ecology of leishmaniasis and the diversity of
  leishmanial species in Central and South
  America., In Farrell, J. (Ed.) World Class
  Parasites Leishmania. Kluwer Academic
  Publishers, Boston, Dordrecht, London, pp. 11-31.