An urgent global
race is under way to establish how and why the Zika virus could be causing a
devastating spike in cases of babies being born with underdeveloped brains in
South America.
Brazil has reported
around 4,000 cases of microcephaly since October – an unprecedented number.
The World Health
Organization has declared a global public health emergency in response.
But experts are
unsure what exactly is behind the rise.
Dr Anthony
Costello, the WHO’s expert on microcephaly, says finding an answer quickly is
imperative.
“We must assume,
given global travel and the like, that this could spread into many other
populations as well.
“What we have
picked up is a surge in cases of microcephaly in two areas where Zika virus has
broken out. First in French Polynesia last year and now, to a much greater
extent, in Brazil.
“We do not know
about cases yet in other areas.”
Zika virus has now
hit more than 20 countries and the WHO believes it is likely to spread
“explosively” across nearly all of the Americas, making the need for fast
answers clear.
Dr Costello says
there will be a lag time of several months to know if pregnant women in these
newly affected countries are safe.
The race is on to
find a better diagnostic test and a vaccine and treatment for Zika as well as
establishing what is making these babies ill.
Microcephaly is not
a new condition. In the US, official reports suggests two to 12 babies per
10,000 born each year have microcephaly – that’s around 25,000 babies a year.
It can be caused by
other infections caught in pregnancy, such as rubella.
Drug and alcohol
abuse by expectant mothers are also factors.
And it can also be
caused by rare genetic conditions.
The difficulty
facing scientists is establishing what is behind each new case.
Research using
animal models is needed to determine if Zika causes damage to an unborn infant
when infection occurs in pregnancy and at what stage, as well as studies of
pregnant women who have unfortunately been infected with Zika virus to
determine the outcomes of their pregnancies.
Dr Costello said:
“We desperately need to have better diagnostics for Zika virus so that we can
look very carefully, if you get pregnant and you get infected, at what is the
risk of getting microcephaly.
“At the moment we
don’t exactly know what the risk is.”
He said although
many pregnant women would, understandably, be very scared at the moment, they
should remember that the risk of their baby having microcephaly was still very
low.
“This is still a
relatively rare occurrence and even if the rates increase, most women are going
to get through pregnancy absolutely fine.”
Babies born with
microcephaly can grow up to have few or no complications. The impact it will
have on their life depends on its severity.
An underdeveloped
brain can lead to seizures, developmental delays, intellectual disability,
problems with movement and balance, hearing loss and visual problems.
Because it is
difficult to predict at birth what problems may lie ahead for a baby with
microcephaly, they need close medical follow-up.
There are things
pregnant women, or those who are likely to be pregnant, can do to protect
themselves against the potential risk:
·
to consider delaying travel to areas affected by Zika
·
seek advice from a physician if they are living in areas
affected by Zika
·
protect themselves against mosquito bites by wearing repellent
and covering up
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