Wednesday, April 8, 2015

Plotting the elimination of dengue

Researchers at the University of Melbourne along with
international collaborators are using a novel way to block the
dengue virus in Aedes aegypti mosquitoes using the insect
bacterium Wolbachia and have for the first time provided projections
of its public health benefit.
Dengue is a viral infection spread between humans by
Aedes aegypti mosquitoes. Dengue causes flu-like
symptoms, including intense headaches and joint
Published in the Journal of Science Translational
Medicine , Professor Cameron Simmons, from the
Department of Microbiology and Immunology at the
University of Melbourne and the Peter Doherty
Institute for Infection and Immunity, said that the
discovery could lead to improved strategies to reduce
the incidence of dengue.
"We did a 'real world' experiment and allowed mosquitoes infected
with Wolbachia and uninfected mosquitoes to feed on the blood of
Vietnamese dengue patients. Our team then measured how efficiently
Wolbachia blocked dengue virus infection of the mosquito body and
saliva, which in turn steps stops them spreading the virus between
humans," Professor Simmons said.
Researchers developed a mathematical model of dengue virus
transmission and used the experimental results as a basis to predict
how well Wolbachia would reduce the intensity of dengue
transmission under a variety of scenarios.
"We found that Wolbachia could eliminate dengue transmission in
locations where the intensity of transmission is low or moderate. In
high transmission settings, Wolbachia would also cause a significant
reduction in transmission.
"Our findings are important because they provide realistic measures
of the ability of Wolbachia to block transmission of the dengue virus
and provide precise projections of its impact on dengue infections,"
Professor Simmons said.
Wolbachia has been recently introduced into Cairns and Townsville
and the results of this study suggest future dengue outbreaks in these
cities should be much less severe than in the past.
"Our results will enable policy makers in dengue-affected countries to
make informed decisions on Wolbachia when allocating scarce
resources to dengue control," Professor Simmons said.
Dengue continues to be a major public health problem in Asia and
Latin America. Estimates suggest more than 100 million cases occur
globally each year.