US officials now believe that Zika causes birth defects. Researchers say an outbreak that began in Brazil in 2015 has likely led to increased microcephaly in infants.
On Wednesday, US health officials announced that they no longer had any doubt that the Zika virus was linked to severe brain defects in babies. Since last year, doctors in Brazil have linked Zika infections in pregnant women to a rise in newborns with microcephaly, or unusually small skulls. The World Health Organization had also recently announced a perceived link.
Doctors have diagnosed microcephaly in more than 1,100 children born in recent months in Brazil, including 198 fatal cases so far, coinciding with the spike in infections since early last year. Researchers are investigating 4,293 suspicious cases.
The CDC cautions that US researchers had found no "smoking gun" to link Zika to microcephaly, according to the full report, published in the New England Journal of Medicine. However, according to the report, "the severe microcephaly and other brain anomalies that have been observed in many infants are consistent with an infection occurring in the first or early second trimester of pregnancy."
'A turning point'
Researchers found a similar increase in birth defects after the 2013-14 Zika outbreak in French Polynesia, though microcephaly cases remained small, totaling just eight. CDC director Tom Frieden said the agency would attempt to "determine whether children who have microcephaly born to mothers infected by the Zika virus is the tip of the iceberg of what we could see in damaging effects on the brain and other developmental problems."
"This study marks a turning point in the Zika outbreak," Frieden said on Wednesday.
Zika transmits via mosquitoes and sex. Officials advise pregnant women and those considering pregnancy to avoid the 30 outbreak regions in the Americasor wear repellant and use condoms during pregnancy if they live in those areas.
Researchers first identified Zika in Uganda in 1947. Until now, doctors had only treated those infected for mild symptoms such as rashes, joint pain and fever. Most people infected report no symptoms at all. Some women infected with Zika while pregnant have delivered children with no signs of microcephaly or other birth defects.
According to a poll, one in four people in the US hadn't heard of a link between Zika and birth defects; one in five believed that pharma had already come forth with a vaccine to prevent infections. Officials expect that the United States will become more acquainted with the Zika virus as mosquitoes emerge during the spring and summer.
Officials have requested $1.9 billion (1.7 billion euros) to prepare for an outbreak. The Republican-led Congress may release a portion of that, legislators said, but probably not before September. Doctors have identified 350 infections in the US so far.
The US Food and Drug Administration has given tentative approval to genetically modified mosquitoes in an attempt to breed out the bloodline of insects carrying the virus, though it is unclear what effect that might have on ecosystems. Scientists say that climate change and deforestation can contribute to the spread of such viruses.
Doctors have identified Zika cases in Asia, as well.
mkg/bw (Reuters, AFP, AP)