New Delhi: Can mosquitos be injected with a vaccine to prevent them from
transmitting the dengue virus to humans? That's what Australian
scientists are working on.
The scientists were in New Delhi looking for a partnership to help
India, which reported the highest dengue cases - 37,000 - in 2012,
control the menace.
The Eliminate Dengue Research Programme is a not-for-profit
international collaboration active in Australia, Vietnam,
Indonesia, China, Singapore, Colombia and Brazil.
The scientists have transferred the Wolbachia bacteria from the
fruit fly into mosquitoes and found that when it is present in the
mosquitos, it reduces their ability to transmit the dengue virus.
In a nutshell, scientists have vaccinated mosquitoes against
dengue, as a result of which they would not be able to transmit it
to humans.
"Wolbachia acts like a vaccine for the mosquito by blocking dengue
virus transmission by mosquitoes and thereby preventing human
infection with dengue," programme manager Peter Ryan told IANS.
The programme is managed by Melbourne's Monash University.
Ryan said the Wolbachia bacteria has the potential to be used
against other insect- transmitted diseases.
"We have demonstrated that Wolbachia's presence in mosquitoes
reduces their ability to transmit other viruses such as
chikungunya and yellow fever as well as parasites that cause
malaria," he said.
Explaining the science behind the research, Ryan said: "Our aim is
to seed wild mosquito populations with bacteria through a
controlled number of releases of Wolbachia-infected mosquitoes
that will then breed with the wild mosquito population."
He said such an experiment was carried out in Australia's Cairn
area that has 1,000 houses in 2011.
"In the last two years, we found that about 80 percent of
mosquitoes cannot transmit dengue. We cannot however say if the
number of dengue cases in humans has come down, as we need a
bigger sample size," Ryan said.
Ryan, who was in New Delhi to attend a biotechnology conference,
said they are ready to share the technology for free so that
countries can innovate and develop it according to their
biological and ecological conditions.
"Dengue is a big problem and many people die of it. We want to
provide a cost-effective and affordable way to countries to deal
with the menace," he said.
The scientists believe they have found a practical and
environmentally sensitive approach to supressing dengue with the
potential for area-wide implementation at a low cost.
"The method is also compatible with existing control approaches
like insecticide application and should also augment the
effectiveness of a future vaccine once developed," Ryan added.
The programme has already been tied up with the Vietnamese
government for conducting trials in the country in the next few
months.
Denying any risk was associated with the release of the Wolbachia
bacteria, Ryan said: "It is safe for humans, animals and the
environment. In each project country we seek approval from the
community before we carry out our tests."
India recorded over 37,000 dengue cases, causing 227 deaths in
2012, the highest number in a year so far, according to the health
ministry.
"The percentage increase in number of cases and deaths between
2011 and 2012 is approximately 97 percent and 34 percent
respectively," Minister of State for Health Abu Haseem Khan
Choudhary said recently.
(Richa Sharma
can be contacted at richa.s@ians.in)
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