There's no longer any doubt that the Zika virus causes birth defects, federal health officials said Wednesday.
The evidence has been piling up and
there really had not been any doubt that Zika was causing horrific
brain damage to unborn babies. But the Centers for Disease Control and
Prevention made it official Wednesday in a publication rushed into the
New England Journal of Medicine.
"It is now clear … that Zika does cause
microcephaly," CDC Director Dr. Tom Frieden told reporters in a
briefing. "We believe the microcephaly is likely to be part of a range
of birth defects."
Zika's been spreading in Brazil and since last
year officials there noted a startling increase in the number of cases
of microcephaly, a birth defect caused by an underdeveloped brain and
marked by a notable small head.
There were doubts at first that Zika, once
thought to be a pretty harmless virus, could actually be causing birth
defects. Until Brazil started raising the alarm, doctors didn't think it
even made most people sick.
Mosquito-borne viruses had never before
been known to cause birth defects, although other viruses, such as
rubella, are notorious for causing them.
But study after study has shown the virus gets
into the developing fetus's brain, killing brain cells, stopping it from
growing and, often, killing the fetus. And it seems to do so at all stages of pregnancy, not just in the first trimester, as most other viruses do.
Advice to pregnant women doesn't change.
"Our previous recommendations regarding how to
prevent and avoid Zika virus infection and transmission remain in
place," the American College of Obstetricians and Gynecologists said.
"Obstetrician-gynecologists should be prepared to counsel their patients regarding the importance of postponing travel to affected areas
if they are planning to become pregnant or if they are pregnant, as
well as the potential need to delay pregnancy with appropriate use of
contraception if women live in affected areas or if travel to these
areas cannot be avoided."
The CDC, the World Health Organization, the
National Institutes of Health and other agencies have been sounding the
alarm about Zika for months. Not only is it spreading across Latin
America and the Caribbean; it is being carried into the United States by
travelers.
It can be spread sexually and in the summer,
when mosquito season starts, it is likely to cause local oubtreaks. It's
already caused outbreaks in the U.S. territories of Puerto Rico, the
U.S. Virgin Islands and Samoa.
CDC
"Reducing exposure to mosquitoes for everyone where the virus is circulating is important," Frieden said.
The Obama administration has asked Congress to
appropriate $1.9 billion to fight Zika, but House Republicans say they
don't want to spend any new money until they are sure all other
available funds are used.
In an unusual retaliation, the White House has
freed up officials such as Frieden and the NIH's Dr. Tony Fauci to plead
for the cash and to outline what other programs will be cut if they
don't get it.
White House press secretary Josh Earnest
released a new salvo Wednesday, saying a bill aimed at speeding up
vaccine development wasn't anywhere near enough to help.
"In some ways, it's akin to passing out umbrellas in advance of a hurricane," Earnest told the White House briefing.
"It's not going to do anything to help local communities across the country," he added. "It doesn't include any funding."
Much more study is needed, as well as a vaccine
to prevent Zika infection, drugs to treat it and better mosquito control
measures, officials say.
"Never before have we seen an illness spread by mosquitoes leading to a birth defect," Frieden said.
And the CDC's Dr. Sonja Rasmussen says it's important to find out fast what else Zika might be doing.
"This doesn't mean that we have all the
answers," she told reporters. Doctors still don't know how many pregnant
women who get Zika will have babies with birth defects. They don't know
what all birth defects there will be, and whether some might show up in
childhood or even adulthood. They don't even know if a woman has to
have symptoms of Zika infection for it to affect her baby.
And there's more evidence that Zika can be passed person to person, and not only through mosquito bites. The CDC's confirmed sexual transmission of Zika and now tells pregnant women to use condoms when having sex if their partner has been to a Zika-affected area.
In a letter to the New England Journal of
Medicine, French doctors reported on a case of sexual transmission of
the virus last February, after a man traveled to Rio de Janeiro, got
infected, and then had sex with a woman in France after he got better.
"We cannot rule out the possibility that
transmission occurred not through semen but through other biologic
fluids, such as pre-ejaculate secretions or saliva exchanged through
deep kissing," Dr. Eric D'Ortenzio of France's INSERM national research
institute and colleagues wrote.
Zika's been found in saliva, and the team said
people need to be warned that there's a possibility they could catch it
that way, they said.
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