Researchers tracked women infected in Colombia and also found troubling cases of severe birth defects in babies born to women who never realized they had contracted Zika.
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For most people, the Zika virus causes only mild symptoms such as fever, rashes, joint pain and conjunctivitis.
“It is somewhat reassuring that we don’t see microcephaly and structural brain abnormalities in those third-trimester infants, but it doesn’t mean everything is good”, said Margaret Honein, a study author and a co-leader of a task force on pregnancy and birth defects task force that is part of the CDC’s Zika response. The virus arrived in Colombia in October 2015, about five months after the start of Brazil’s outbreak.
Honein says longer-term studies of pregnant women and their babies are needed. It’s possible, she said, that the babies may still develop problems.
It’s not surprising that infections later in pregnancy did not lead to apparent defects, because experts know that Zika and other viral infections early in pregnancy are more likely to cause defects like microcephaly, said Dr. Neil Silverman, a UCLA professor of obstetrics who has been advising the California Department of Public Health on Zika issues. Although the number of cases of birth defects appears lower in Colombia so far, “it is premature to conclude there is a difference” in the rates of affected babies, she says.
For example, it’s still unclear whether Zika infections late in pregnancy raise the risk for other complications, such as miscarriages or stillbirths.
Honein said the infants in Colombia need to be watched for other potential effects of Zika infection, such as hearing loss or vision problems, or any other developmental problems. A preliminary report from Rio de Janeiro, published in March in the New England Journal of Medicine, found a range of abnormalities in 29% of Zika-infected women, including women who had been infected in their third trimesters.
Last month, USA health officials reported that the number of pregnant women in the United States infected with the Zika virus had tripled because cases were now being counted in a more comprehensive way.
The cohort of women in the Rio study had all tested positive for Zika, while the women in the Colombia study had Zika symptoms but not all were confirmed by lab tests. Those findings support evidence that Zika can produce birth defects whether or not the mother herself becomes visibly sick from the virus.
Negotiators officially met on Wednesday, but only to make opening speeches to satisfy a requirement for at least one public negotiating session. And if you have to, do everything you can to not get bitten by mosquitoes.
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President Barack Obama requested $1.9 billion four months ago.
