A baby born in Hawaii with a birth defect that affects head size had also been infected with Zika virus, state health officials said Saturday. The finding even more strongly links the fast-spreading virus with the defect, called microcephaly.
"The Hawaii State Department of Health has received laboratory confirmation from the U.S. Centers for Disease Control and Prevention (CDC) of a past Zika virus infection in a baby recently born with microcephaly in a hospital on Oahu," the health department said in a statement posted on its website.
"The mother likely had Zika infection when she was residing in Brazil in May 2015 and her newborn acquired the infection in the womb. Neither the baby nor the mother are infectious, and there was never a risk of transmission in Hawaii," the health department said.
On Friday night, the CDC issued a travel advisory suggesting that pregnant women put off travel to affected regions, and issued a health alert to doctors to be on the lookout for the virus.
Microcephaly is an often severe birth defect that can kill an unborn child or cause disabilities throughout life. The brain and head are smaller than usual. The condition can be caused by genetics, alcohol use during pregnancy or infections such as rubella.
Zika had never before been suspected of causing microcephaly and was considered a fairly benign virus. It's a cousin of dengue virus but only causes symptoms in about one in four or one in five people.
But Brazil has been raising increasingly loud alarms about Zika. The virus only showed up there last year but it's rapidly spread, carried by mosquitoes that bite infected people and carry it to others.
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At the same time, Brazil noticed a startling increase in the numbers of microcephaly cases. Then CDC and other experts found evidence of the virus in babies diagnosed with microcephaly.
Zika has now been found in 14 countries in the Americas, from Colombia to Mexico.
It's not been found in Hawaii yet except carried by travelers like the mother and her child. But Hawaii suffers outbreaks of dengue and the same mosquitoes that carry dengue are found there, so the state is vulnerable.
"We are saddened by the events that have affected this mother and her newborn," Hawaii's state epidemiologist, Dr. Sarah Park, said in a statement. "This case further emphasizes the importance of the CDC travel recommendations released today."
Park said the case highlights the importance of reducing mosquito populations, avoiding areas where the insects are likely to be, and to use mosquito repellent.
It will take months for scientists to fully understand how and why Zika might cause birth defects and to figure out why it had not been noticed before.
Before 2015 Zika had only been seen in parts of Africa, southeast Asia and some Pacific islands.
"Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing. Pregnant women who do travel to one of these areas should talk to their doctor or other healthcare provider first and strictly follow steps to avoid mosquito bites during the trip," CDC advised.