The antibodies were harvested from the blood of a patient in China who became ill in Venezuela.
"We're recommending pregnant women not travel to Brownsville, and if they do travel to that area, to ensure that they avoid mosquito bites and they avoid the risk of sexual transmission", the CDC's Dr. Denise Jamieson said in an agency news release. Among them, 53% tested positive for Zika. The previous study was based mainly on prenatal ultrasound findings; by contrast, the current research evaluated infants from Zika-affected pregnancies through physical examination and brain imaging.
Earlier this year, a link between Zika virus infection and microcephaly was confirmed, making the possibility of contracting the infection during pregnancy all the more threatening. Among pregnant women in the United States with completed pregnancies and laboratory evidence of possible recent Zika infection, 6% of fetuses or infants had Zika-associated birth defects. There were four cases of microcephaly among the 125 infected women, or 3.4%.
Some 55% of pregnant women infected in their first trimester had poor pregnancy outcomes, as did 52% of those infected in their second trimester and 29% of those infected in their third trimester. The adverse outcomes include miscarriage, calcifications in a baby's brain, babies who are smaller than normal, and brain hemorrhages.
Abnormalities of the central nervous system were seen in fetuses infected as late as 39 weeks of gestation, the researchers said. They were studying different populations of women and babies affected by a disease which is hard to detect and defects which are hard to define.
Dr. Karin NielsenPhoto credit: UCLANew UCLA-led research finds that Zika-linked abnormalities that occur in human fetuses are more extensive-and severe-than previously thought, with 46 percent of 125 pregnancies among Zika-infected women resulting in birth defects in newborns or ending in fetal death. For the first time, the data in the study also show that there was virtually no difference in the rate of birth defects between women who had symptoms of Zika and those without symptoms. Among this group, 11% had a fetus or infant with a birth defect. "The 18 infants with a finding of microcephaly represent 4 percent (18/442) of the completed pregnancies; this prevalence is substantially higher than the background prevalence of microcephaly in the United States of about 7 per 10,000 live births, or about 0.07 percent of live births", CDC reported. That's important because most people who get infected don't have any symptoms, said Margaret Honein of the Centers for Disease Control and Prevention, one of the study's authors. But that state was recently declared Zika-free after 45 days passed without any new infections in the last active zone, located in South Miami Beach. Thousands of babies have been born in Brazil and Colombia with microcephaly, a birth defect that results in an abnormally small head and an underdeveloped brain. "More studies are needed to fully understand how the virus can affect babies".