Cheese dogs and a pill to kill mosquitoes and end malaria Bart Knols
gotcha mosquitoes I hate them don’t you
that awful buzzing sound at night around
your ears that drives me absolutely
crazy knowing that she wants to stick a
needle in your skin and suck out your
blood that’s awful right in fact there’s
only one good thing I can think of when
it gets to mosquitoes when they fly into
our bedroom at night they prefer to bite
my wife but that’s fascinating right
why does she receive more bites than I
do
and the answer is smell the smell of our
body and since we all smell different
and produce chemicals on our skin that
either attract or repel mosquitoes some
of us are just more attractive than
others so my wife smells nicer than I do
or I just stink more than she does
either way either way mosquitoes find us
in the dark by sniffing us out
they smell us and during my PhD I wanted
to know exactly what chemicals from our
skin mosquitoes used African malaria
mosquitoes use to track us down at night
there’s a whole range of compounds that
they do use and this was not going to be
an easy task and therefore we set up
various experiments why did we set up
these experiments because half the
world’s population runs the risk of
contracting a killer disease like
malaria through a simple mosquito bite
every 30 seconds somewhere on this
planet a child dies of malaria and Paula
levy this morning he was talking about
the metaphor of the 77 crashing in the
United States well in Africa we have the
equivalent of seven jumbo 747 crashing
every day
perhaps if we can attract these
mosquitoes to traps bait it with our
smell we may be able to stop
transmission of disease now solving this
puzzle was not an easy thing because we
produced hundreds of difference of
chemicals on the skin but we undertook
some remarkable experiments that managed
us to resolve this puzzle very quickly
indeed first we observed that not all
mosquito species bite on the same part
of the body strange so we set up an
experiment whereby we put a naked
volunteer in a large cage and in that
case we release mosquitoes to see where
they were biting on the body of that
person and we found some remarkable
differences on the left here you see the
bites by the Dutch malaria mosquito on
this person there’s a very strong
preference for biting on the face in
contrast the African malaria mosquito
had a very strong preference for biting
the ankles and feet of this person and
that of course we should have known all
along because they’re called mosquitoes
you see that’s right and so and so we
started focusing on the smell of feet on
the smell of human feet until we came
across a remarkable statement in the
literature that said that cheese smells
after feet rather than the reverse think
of it and this triggered us to do a
remarkable experiment we tried with a
tiny little piece of Limburger cheese
which smells badly after feet to attract
African malaria mosquitoes and you know
what it worked
in fact it worked so well that now we
have a synthetic mixture of the aroma of
Limburger cheese that were using in
Tanzania and has been shown there to be
2 to 3 times more attractive to
mosquitoes than humans Limburg be proud
of your cheese as it is now used in the
fight against malaria
that’s the cheese just to show you my
second story
it’s remarkable as well it’s about man’s
best friend it’s about dogs and I will
show you how we can use dogs and the
fight against malaria one of the best
ways of killing mosquitoes is not to
wait until they fly around like adults
and bite people and transmitted disease
it’s to kill them when they’re still in
the water as larvae why because they’re
just like the CIA in that pool of water
these larvae are concentrated they’re
all together there they are in mobile
they can’t escape from the water they
can’t fly and and they’re accessible you
can actually walk up to that tool and
you can kill them there right so the
problem that we face with this is that
throughout the landscape all these pools
are falta with a larvae they’re
scattered all over the place
which makes it very hard for an
inspector like this to actually find all
these breeding sites and treat them with
insecticides the last year we thought
very very hard how can we resolve this
problem until we realized that just like
us we have unique smell that mosquito
larvae also have a very unique smell and
so we set up another crazy experiment
because we collected the smell of these
larvae put it on pieces of cloth and
then did something very remarkable here
we have a bar with four holes and we put
the smell of these larvae in the left
hole whoo that was very quick and then
you see the dog
it’s called tweet it’s a border collie
he’s examining these holes and now he’s
got it all ready he’s going back to
check the control holes again but he’s
coming back to the first one and now
he’s locking into that smell which means
that now we can use dogs with these
inspectors to much better find the
breeding sites of mosquitoes in the
field and therefore have a much bigger
impact on malaria this lady is Alan from
Goss wave she’s one of the best dog
trainers in the world and she believes
that we can do a lot more since we also
know that people that carry malaria
parasite
smell different compared to people that
are uninfected she’s convinced that we
can train dogs to find people that carry
the parasite that means that in the
population where malaria has gone down
all the way and there’s food few people
remaining with parasites that the dogs
can find these people we can treat them
with anti malarial drugs and give a
final blow to malaria man’s best friend
in the fight against malaria my third
story is perhaps even more remarkable
and I should say has never been shown to
the public until today yeah it’s a crazy
story but I believe it’s perhaps the
best and ultimate revenge against
mosquitoes ever in fact people have told
me that now they will enjoy being bitten
by mosquitoes and the question of course
is what would make someone enjoy being
bitten by mosquitoes and the answer I
have right here in my pocket if I get it
it’s a tongueless simple tablet and when
I take it with water it does miracles
thank you now let me show you how this
works here in this box I have a cage
there’s several hundred hungry female
mosquitoes
that I’m just about to release just
kidding just kidding what I’m going to
show you is I’m gonna stick my arm into
it and I will show you how quickly they
will bite there we go
don’t worry I do this all the time in
the lab there we go okay now on the
video on the video here I’m gonna show
you exactly the same thing except that
what I’m showing you in the video
happened one hour after I took the
tablet have a look that doesn’t work
okay sorry about that I’m sticky getting
my arm I’m giving them a big juicy blunt
meal I’m shaking them off and we follow
them through time to see these mosquitos
get very very sick indeed here shown in
fast motion and three hours later what
we see on the bottom of the cage is dead
mosquitoes very dead mosquitoes and I’m
going to say ladies and gentlemen we
have swapped the cards with mosquitoes
they don’t kill us we kill them
now Maslak vp prayers now think of what
we can do with this we can actually use
this to contain outbreaks of
mosquito-borne diseases of epidemics
right and better still imagine what
would happen if in a very large area
everyone would take this drugs this drug
for just three weeks that would gives an
opportunity to actually eliminate
malaria as a disease so cheese dorks and
a pill to kill mosquitoes that’s the
kind of out-of-the-box science that I
love doing for the betterment of mankind
but especially for her so that she can
grow up in the world without malaria
thank you