Mosquito defense may have a new secret weapon.
It looks like a
nicotine patch, but the little diamond-shaped
Kite Patch is laced with a very special sauce
that its developers claim can protect whoever
wears it from mosquito bites for up to 48
hours.

For many, mosquitoes are merely annoying,
but in many parts of the world they spread
malaria, a deadly disease that is far more
dangerous than many health authorities had
previously guessed.

The average mosquito has long-range sensors
that can sense the carbon dioxide humans
emit through their breath from up to a half-
mile away. The mosquito's sensing organ, the
maxillary palp, contains a neuron called the
cpA neuron that pings the mosquito's brain
when it senses CO2.

The active ingredient and most effective
commercially available mosquito repellent is
DEET, which works by confusing these sensors.
But some research suggests it can be toxic,
especially to children . It is also a bit too
expensive for everyday use, especially in the
poorer countries stricken with mosquito-
borne diseases. Oh yeah, and it melts plastic.

Chemical mystery
The Kite Patch developer, Olfactor
Laboratories, says that their product works in
much the same way as DEET — blocking
mosquitoes' carbon dioxide receptors. But,
the Kite Patch uses chemicals that are so safe
they are considered "food grade flavors" by
the Food and Drug Administration.
Presumably the patch would be safer than
repellents made from chemicals like DEET,
PMD, and Picaridin.

The magical compounds are based on
research done by Anandasankar Ray's
laboratory at the University of California,
Riverside, which owns the intellectual
property on which the formula is based. They
aren't releasing the actual ingredients in the
patch, but we can guess about its contents
from previous research from their group.
Scientist Stephanie Turner and colleagues
observed that fruit flies were attracted to
ripening fruit in spite of the fact that it emits
carbon dioxide — a chemical the flies use to
warn each other of danger. They found that
fruit also emits odors that prevent the flies
from detecting the CO2, allowing the flies to
locate the fruit.

Building on this research, the team identified
several compounds that block mosquitoes
from sensing CO2, including 2,3-butanedione,
1-hexanol, 1-butanal, and 1-pentanal. These
could very well be the secret ingredients in
the Kite Patch.

Testing the patch
Olfactor Laboratories has been raising money
to test the patch in Uganda, which Kite co-
founder calls "one of the toughest proving
grounds there is" because of its huge
mosquito population and high rates of malaria
infection. If that works, they expect — with
EPA approval — to market the three-square-
inch patch in the United States in about a
year.

The group has already raised money from the
Gates Foundation and the National Institute of
Health, and they've started an indiegogo
campaign to pay manufacturing costs. You
have until August to invest, and for $10 you
can fund you can fund the field testing of 5
patches in Uganda. For $35 you can give 10,
and then receive 10 if they are approved by
the EPA.

Kite is a "spatial"
protectant. You put a
tiny square
somewhere on your
shirt and it emits a
chemical signal that
protects a larger area
of space. This places
it in a class similar
to the citronella
candles and mosquito
coils sitting on tables
in backyards all over
America.

It has a shelf life of 18 months and should
have about the same effect on clothing as a
commercially sold sticker would, according to
the company.
This also makes it different from many topical
solutions that really only protect the skin to
which they are applied.
Cameron Webb, a researcher at the University
of Sydney, wrote a blog post about how
already-on-the-market spatial protectants
perform against mosquitoes in tests. He has
reservations about the patch, but hasn't
gotten to test it.

He said:
"Products claiming to be 'spatial
repellents' such as mosquito coils and
sticks offer some protection if they
contain insecticides (and therefore
'knock down' nearby mosquitoes). But
there is growing opinion amongst experts
that these provide only limited
protection against nuisance-biting and/or
mosquito-borne disease risk. Australian
studies have shown that burning devices
like this that contain botanical products
provide a reduction in landing
mosquitoes of approximately 70%. The
same study found that a topical
application of DEET stopped 100% of
landings."

70% still is not bad, you might think, and it is
enough to reduce annoyance and itchiness.
However, as Webb notes, it is not necessarily
enough to prevent malaria or Dengue fever.
Webb himself has tested botanical spatial
wrist-bands made from botanical compounds,
and found they only kept mosquitoes from
alighting on the area immediately around the
band. The little blood-suckers still landed on
skin only 4 inches away from where the band
was worn.

So, basically, spatial repellents don't have
great records when it comes to preventing
mosquito bites and transmission of mosquito-
born diseases, but Olfactor Laboratories is
hoping the Kite Patch will succeed where
others have failed.