Nevertheless the reduction of the number of

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Nevertheless the reduction of the number of
malaria deaths is one of the main reasons for
the dramatic increase of the world
population since the end of WWII.
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Mosquitoes basic biology

• Larvae and pupae always found in water.
• Adult mosquitoes of both sexes feed on nectar.
• Females of most species need a blood meal for egg
  development.
• In temperate climate diapause (adults in dormant
  state) or produce dormant eggs.

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Mosquitoes basic biology II

• Three major breeding groups
• Permanent water breeders Anopheles and many
  Culex in swamps, ponds, lakes, and ditches.
• Floodwater breeders salt marsh, inland flood
  water, and rice field mosquitoes.
• Artificial container/tree hole breeders Aedes
  aegypti and Aedes albopictus.

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Mosquitoes as vectors

• Aedes filaria, viruses (e.g. Aedes aegypti for
  dengue and yellow fever).
• Anopheles malaria, filaria (Wuchereria
  bancrofti) , viruses.
• Culex filaria, viruses (e.g. Culex pipiens for
  SLE).

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Aedes aegypti

• Worldwide within the 20C isotherms.
• Vector of yellow fever and dengue.
• Urban mosquito.
• Daytime biting mosquito.

Goddard J. 2003. CRC Press
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Aedes albopictus

• Asian Tiger Mosquito.
• Agressive, daytime biting mosquito.
• Associated with used automobile tires.
• Vector of yellow fever, dengue and Lacrosse
  encephalitis virus.

Goddard J. 2003. CRC Press
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Aedes albopictus

• Asian Tiger Mosquito.
• Agressive, daytime biting mosquito.
• Associated with used automobile tires.

Goddard J. 2003. CRC Press
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Aedes albopictus

• Asian Tiger Mosquito.
• Agressive, daytime biting mosquito.
• Chikungunya outbreak in Réunion, a French
  overseas département.
• Arboviral disease.
• Fever and arthralgias.

Eurosurveillance. 2006. Volume 11. Issue 1, at
http//www.eurosurveillance.org/
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Aedes albopictus

• Chikungunya fever in the province of Ravenna,
  Italy A. albopictus is the most likely vector
• A. albopictus in Belgium, the Netherlands,
• Eurosurveillance. 2007. Volume 12. Issue 9, at
  http//www.eurosurveillance.org/
• A. albopictus in NL via lucky bamboo from
  SE-China.
• Ned Tijdschr Geneeskd. 2007. 1511333-1338.

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Anopheles labranchiae atroparvus

• Ziet gij muggen lang van poot? Aarzelt niet, maar
  slaat ze dood.
• Main malaria vector in the Low Countries.
• Lived in pig stables (Vapona strip) and attics
  (Sprays).
• The larvae are found in brackish water along the
  coast from the southern Baltic to Spain.

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Anopheles gambiae

• Most important vector in Africa.
• lt 1000 m
• 2 (7) km
• 0 4 h maximal activity.
• Endophilic species.

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Anopheles gambiae

• 1930 Brazil.
• 1937-1938 large fatal epidemics associated with
  A. gambiae in Brazil.
• 1939-1941 eradicated from Brazil.
• 1943-1945 eradicated from Egypt.

The Lancet Infectious Diseases. 2002. 2618-627.
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UK NEQAS Parasitology on the web

• Approximately 60 different species of Anopheles
  mosquitoes can transmit malaria.

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Malaria transmission

• Mosquito to man
• Blood transfusion
• Mother to child

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American Civil War (1861-1865) patients with
mosquito nets, Washington D.C.
50 of the white soldiers got malaria annually
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Alphonse Laveran(1845-1922)

• Physician of the French Army.
• 1880 Constantine, Algeria, The malaria parasite
  Laveriana, Plasmodium.
• Nobel Prize in 1907.

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Sir Ronald Ross (1857-1932) 20 August 1897
mosquito day

• Surgeon-Major in the British Indian Medical
  Service wrote to his wife
  I know that this little thing a million men
  will save.
• Studied bird malaria.
• Nobel Prize in 1902.

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Battista Grassi

• 1899
• Only female mosquitoes are able to transmit
  malaria.
• Blood is necessary for oogenesis.

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Courtesy CDC
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• Plasmodium falciparum limited to (sub-) tropical
  areas (summer isotherm of 20C, altitude lt 2000
  m).

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Sporogony in the mosquito

• Plasmodium falciparum
• 8 days at 30C
• between 20 (18) and 33C
• Plasmodium vivax
• development occurs at 16C

M. Wéry, 1995.
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Developmental period in mosquito

• Plasmodium falciparum 22 days at 20C, 10 days
  at 27C (minimal temperature (18) 2OC)
• Plasmodium malariae 30-35 days at 20C, 25 days
  at 24C (minimal temperature 16C)
• Beaver et al. 1984.

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Developmental period in mosquito

• Plasmodium ovale 16 days at 25C, 14 days at
  27C (minimal temperature (18) 2OC)
• Plasmodium vivax 30 days at 16C, 16 days at
  20C, 10 days at 30C (minimal temperature 16C)
• Beaver et al. 1984.

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Malaria Vector Control

• Source reduction (larval control)
• Historically most effective campaign in Brazil
  and Egypt (1930s and 1940s).
• Bacillus thurigiensis var. israelensis (Bti
  toxins).
• Mosquito fish (Gambusia affinis) larger bodies
  of water.

CDC, www.cdc.gov/malaria/
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New strategy against Aedes aegypti in Vietnam

• Kay B., Nam V. 2005. Lancet 365613-617.
• Major sources of A. aegypti are large water
  storage containers.
• 1998-2003 Elimination from 32 of 37 communes
  with Mesocyclops spp. (cyclopoid copepods)
  (309730 people).
• No dengue cases since 2002.

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New strategy against Aedes aegypti in Vietnam

• Kay B., Nam V. 2005. Lancet 365613-617.
• Mesocyclops spp. (cyclopoid copepods)
• WHO only in countries free of Guinea worm
  (Mesocyclops spp. are intermediate host)
• Gnathostoma and Diphyllobothrium ?

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Malaria Vector Control

• Indoor residual spraying
• DDT, dieldrin
• more expensive insecticides
• failure of eradication (1955-1969)
• environmental concerns
• Insecticide-treated bed nets
• pyrethroid insecticides
• nets retreated at 6-12 months

CDC, www.cdc.gov/malaria/
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DDT

• Dichloro-diphenyl-trichloroethane.
• 1874 German chemist Othmer Zeidler.
• 1939 Paul Hermann Müller (1899-1965) in
  Switzerland (J.R. Geigy A.G., Basle).
• WWII louse-borne typhus, malaria.
• 1948 Nobel Prize Medicine.

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Parasitology

• orphan parasites
• orphan drugs
• The disaster of the ban of DDT.
• The Lancet. 2000. 356 265 and 1189.
• 2001 indoor residual spraying with DDT resumed
  in S. Africa and malaria cases fell.
• The Lancet. 2007. 3691922.
• (orphan reimbursement, B)

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DDT indoor residual spray,

• Still an effective tool to control Anopheles
  fluviatilis transmitted Plasmodium falciparum
  in India.
• Gunasekaran K. et al. 2005. Trop Med Int Health,
  10160-168.

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Eradication of malaria 1934 Hans Andersag at
Bayer discovers chloroquine 1939 Paul Müller at
Geigy discovers DDT 1951 Sardinia malaria
free 1955 WHA (WHAssembly) goal of global
eradication 1955-1969 WHO uses DDT and
chloroquine 50s DDT-resistance 1962-1970
chloroquine-R 1955-1965 expenditure of 1.4
billion 1969 WHO back to malaria control 1975
Europe free of malaria for first time
in history
Courtesy of C.D.C
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Recent history of the World Bank's work on
malaria The World Bank co-founded the Roll
Back Malaria (RBM) Partnership in 1998. Since
July 2000, the Bank has committed about
US100-150 million in funds earmarked for
malaria control. This includes only health
sector investment credits and grants, as well as
commitments through broad programmatic
operations such as Sector-Wide Approaches
(SWAps). Total World Bank support for malaria
control was higher, due to financing through
debt relief, multisectoral operations such as
Poverty Reduction Support Credits (PRSCs),
Emergency Recovery Credits and Social Funds.
However, it is difficult to quantify exactly how
much of these programmatic operations went to
malaria control, since such operations do not
track details of inputs into specific disease
control programs.
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RBM is enabling countries to take effective,
sustainable action against malaria by focusing
on

1. preventing and controlling malaria during
   pregancy
2. promoting the use of insecticide-treated mosquito
   nets as a means of prevention
3. dealing effectively with malaria in emergency and
   epidemic situations.
4. providing prompt access to effective treatment