Home' Trinidad and Tobago Guardian : June 6th 2013 Contents B28
body & soul
Guardian www.guardian.co.tt Thursday, June 6, 2013
For decades, health officials have battled malaria
with insecticides, bed nets and drugs. Now, scien-
tists say there might be a potent new tool to fight
the deadly mosquito-borne disease: the stench of
In a laboratory study, researchers found that mos-
quitoes infected with the tropical disease were more
attracted to human odours from a dirty sock than
those that didn t carry malaria. Insects carrying
malaria parasites were three times more likely to be
drawn to the stinky stockings.
The new finding may help create traps that target
only malaria-carrying mosquitoes, researchers say.
"Smelly feet have a use after all," said Dr James
Logan, who headed the research at the London
School of Hygiene and Tropical Medicine. "Every
time we identify a new part of how the malaria
mosquito interacts with us, we re one step closer to
controlling it better."
The sock findings were published last month in
the journal, PLoS One.
Malaria is estimated to kill more than 600,000
people every year, mostly children in Africa.
Experts have long known that mosquitoes are
drawn to human odours, but it was unclear if being
infected with malaria made them even more attracted
to us. Infected mosquitoes are believed to make up
about one per cent of the mosquito population.
Using traps that only target malaria mosquitoes
could result in fewer mosquitoes becoming resistant
to the insecticides used to kill them. And it would
likely be difficult for the insects to evade traps based
on their sense of smell, scientists say.
"The only way mosquitoes could (develop resist-
ance) is if they were less attracted to human odours,"
said Andrew Read, a professor of biology and ento-
mology at the University of Pennsylvania, who was
not part of Logan s research. "And if they did that
and started feeding on something else---like cows---
that would be fine."
Read said the same strategy might also work to
target insects that carry other diseases such as dengue
and Japanese encephalitis.
In a related study, Logan and colleagues also sealed
human volunteers into a foil bag to collect their body
odour as they grew hot and sweaty. The odours were
then piped into a tube next door, alongside another
tube untainted by human odour. Afterwards, mos-
quitoes were released and had the option of flying
into either tube. The insects buzzed in droves into
the smelly tube.
Logan said the next step is to identify the chemicals
in human foot odour so that it can be made syn-
thetically for mosquito traps. But given mosquitoes
highly developed sense of smell, getting that formula
right will be challenging.
Some smelly cheeses have the same odor as feet,
"But mosquitoes aren t attracted to cheese because
they ve evolved to know the difference," he said.
"You have to get the mixture, ratios and concen-
trations of those chemicals exactly right otherwise
the mosquito won t think it s a human."
Scientists said it s crucial to understand the sub-
tleties of mosquito behavior. Other studies have
shown mosquitoes don t become attracted to humans
for about two weeks---the time it takes for the malaria
parasites to become infectious for humans.
"At the moment, we only have these glimpses of
how parasites are manipulating the mosquitoes,"
Using traps that only target malaria
mosquitoes could result in fewer mosquitoes
becoming resistant to the insecticides used
to kill them. And it would likely be difficult
for the insects to evade traps based on their
sense of smell, scientists say.
A researcher works on a mosquito stock cage in a mosquito laboratory at the
London School of Hygiene and Tropical Medicine in London. Researchers at the
school have discovered that malaria-infected mosquitoes are more attracted to
human odours. AP PHOTO
YOUR DAILY HEALTH
News and advice
Stinky feet may lead
to better malaria traps
said George Christophides, chair of infectious disease
and immunity at Imperial College London. "We
need to exploit that information to help us control
Links Archive June 5th 2013 June 7th 2013 Navigation Previous Page Next Page