Mosquito/Malaria Control (42)
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Hi Folks,
I'm still waiting for anybody to tell me some place in the world
that has ever controlled malaria without the broad use of insec-
ticides. I have posted this challenge some time ago. Still no
responses. If nothing is forthcoming, I will have to assume that
it has never been done.
Thanks Guys,
Bill Nesler
West Coast Aerial Applicators
mailto:sdbc@hur.midco.net
Mosquito/Malaria Control (43)
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Dear Mr. Nesler,
This is in response to your 'challenge' of a place in the world
that has controlled malaria without the broad use of insecti-
cides.
Here is a link for a paper that documents the suppression of ma-
laria transmission in Northern Rhodesia in the 1930s and 1940s
using an integrated program with a focus on environmental man-
agement:
Efficacy and cost-effectiveness of environmental management for
malaria control
By Jürg Utzinger, Yesim Tozan and Burton H. Singer
Submitted to: Tropical Medicine and International Health
11/05/2001
Adobe PDF file (29 pp. 176 kB):
http://wws.princeton.edu/chw/papers/malaria.pdf
There are also well documented stories of malaria being 'con-
trolled' (actually a better word is suppressed when the risk of
new infections is reduced) in India, Malaysia, Indonesia and ur-
ban areas of Africa before insecticides, unfortunately, became
the central focus of anti-malaria programs. The history of anti-
malaria programs shows that an integrated (using more than one
intervention) approach with a focus on environmental management
is the most sustainable means of suppressing malaria transmis-
sion, especially in areas where transmission is intense. The use
of an insecticide intensively and extensively in an area of in-
tense transmission will eventually lead to resistance and is not
the 'magic bullet' solution that many people would like to be-
lieve.
Are you in the insecticide application business Mr. Nesler? You
list 'West Coast Aerial Applicators' after your name.
Derek Willis
mailto:willis@Princeton.EDU
Mosquito/Malaria Control (44)
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Derek, don't bother talking sense to some people we all tried
and failed... but you can tell from the signature at the bottom
of the page what the person does... "as in occupation wise" and
why he speaks like he does and insists on the things he does.
Any way... I hope he finds someone to use his services since
President Bush has just offered large amounts of cash to be used
in the management of malaria and its vectors and I bet there
will be some spent on spraying though I bet it will not be on
large scale "farm style" spraying but on IRS, which all sensible
science oriented people also support.
Isaac Kigozi
mailto:kigoziisaac76@yahoo.co.uk
Mosquito/Malaria Control (45)
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Isaac,
Something that must be understood is that we are not discussing
farm style spraying here. In agricultural operations 1 to 10
gallons per acre is in the normal application range. In mosquito
control operations less than one ounce per acre is the norm, re-
sulting in a 95% or greater mortality in the mosquito popula-
tion. If this type operation is sustained in a judicious manner,
the impact on malaria transmission will be quite dramatic. In
combination with the other methods of mosquito/malaria control,
the disease can be eradicated in a given locality and recurrence
prevented.
Those are the facts. It has been done and can be done in tropi-
cal Africa, given the will and funding necessary. If all of us
just throw up our hands and say it can't work, it's guaranteed
not to.
Bill Nesler
mailto:sdbc@hur.midco.net
Mosquito/Malaria Control (46)
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What will you do when resistance eventually develops to the in-
secticide you are using? Even if you kill 95% of the mosquitoes
you will not eliminate transmission in areas of holoendemic ma-
laria.
Derek W Willis
mailto:willis@Princeton.EDU
Mosquito/Malaria Control (47)
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Resistance and the mechanisms that cause it in mosquitoes is far
better understood today than when resistance first became appar-
ent. This phenomenon can be pretty well avoided by rotation of
insecticides used and using different classes of insecticides
for IRS, outdoor ULV, and larvaciding. 95% is the minimum mor-
tality rate. In most cases the real number is more like 99%.
This is referring only to adulticiding activities. When the
other methods are added to this, the effects can be quite dra-
matic.
I also agree with you that rural areas present a different prob-
lem that is much more difficult to address, but not impossible.
Bill Nesler
mailto:sdbc@hur.midco.net