Stark claim comes ahead of WHO’s emergency
meeting, with notional vaccine-testing on pregnant women a ‘practical and ethical
nightmare’
The Zika virus outbreak in Latin America could be
a bigger threat to global health than the Ebola epidemic that killed more than
11,000 people in Africa.
That is the stark claim of several senior health
experts ahead of an emergency meeting of the World Health Organisation on
Monday which will decide whether the Zika threat – which is linked to an
alarming rise in cases of foetal deformation called microcephaly – should be
rated a global health crisis.
“In many ways the Zika outbreak is worse than the
Ebola epidemic of 2014-15,” said Jeremy Farrar, head of the Wellcome Trust.
“Most virus carriers are symptomless. It is a
silent infection in a group of highly vulnerable individuals – pregnant women –
that is associated with a horrible outcome for their babies.”
There is no prospect of a vaccine for Zika at
present, in contrast to Ebola, for which several are now under trial. “The real
problem is that trying to develop a vaccine that would have to be tested on
pregnant women is a practical and ethical nightmare,” added Mike Turner, head of
infection and immuno-biology at the Wellcome Trust.
With at least 80 per cent of those infected
showing no symptoms, tracking the disease is extremely difficult. The mosquito
species that spreads Zika, Aedes aegypti, has been expanding its range over the
past few decades. “It loves urban life and has spread across the entire
tropical belt of the planet, and of course that belt is expanding as global
warming takes effect,” added Farrar.
Only extreme measures are likely to contain the
Zika threat, said Turner. These could include the use of DDT to eradicate Aedes
aegypti as quickly as possible.
“We have to balance the risk posed to the
environment by DDT with the terrible impact this virus is having on the
unborn.”
Britain is unlikely to be affected because Aedes
aegypti cannot survive the cold of UK winters. However, couples returning from
south or central America have been warned not to try for a baby for at least a
month in case they have become infected.
Public Health England said that the risk of
sexual transmission of Zika was low, but it had been recorded in a limited
number of cases.
Source–Science Daily
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