February 26: Reports of people sickened by Zika virus are growing quickly in the U.S., the Centers for Disease Control and Prevention saidÂ Friday, illustrating serious challenges posed by frequent travel to and from regions affected by the virus.
Details provided by the agency also suggest that pregnant women face significant risk from the disease. Five of nine pregnant women who traveled to affected areas and had Zika symptoms had complications.
The CDC said it has received 147 reports of Zika illnesses to date. Of those cases, 107 were travelers who brought the disease home. Another 40 are cases involving people who were infected locally, mostly in Puerto Rico and other U.S. territories.Â Puerto Rico has confirmed 117 cases overall, making it the most affected U.S. area, CDC Director Tom Frieden said in a news briefing.
The pregnancy complications, as well as 14 reports of possible sexual transmission, have surprised CDC officials. â€œWe did not anticipate we would see this many sexually transmitted cases of Zika,â€ Dr. Frieden said.
That, and the number of abnormalities the agency discovered in the unborn children of pregnant women, caused Dr. Frieden to reiterate forcefully the agencyâ€™s recommendations about prevention. Scientists are continuing to find new signs of a link between Zika and microcephaly, a serious birth defect in which babies are born with undersized brains and skulls, he said. â€œThe evidence is getting stronger by the day,â€ he said.
â€œIf youâ€™re pregnant, avoid travel to a place where Zika is spreading,â€ he said. Pregnant women who live in an area where the virus is circulating should take precautions to avoid mosquito bites and sexual transmission, he said.
On Friday, the CDC advised pregnant women to consider not going to the 2016 Summer Olympic Games in Rio de Janeiro, Brazil, to reduce their chances of picking up the virus. The virus has been detected across much of the South American country, and a number of babies have been born with Zika-linked microcephaly.
The CDC is also expanding the availability of diagnostic tests for Zika to more than 20 qualified laboratories, he said. He said pregnant women who have traveled can be tested for Zika two to 12 weeks after their return.
President Barack Obama has asked Congress for $1.9 billion to combat Zika, $828 million of which would go to the CDC for work such as expanding laboratory capacity around the country.
Zika is circulating in 34 countries and territories, according to the CDC.
The agency said it had reports of nine pregnant women confirmed with Zika infection and is investigating 10 other possible cases.Â The nine women were all infected in Zika-affected areas, including Puerto Rico, Mexico, Haiti and American Samoa.
Two women had miscarriages, one gave birth to a baby with microcephaly, and two terminated their pregnancies, the agency said.Â Two other infants were born healthy, and two women are still pregnant.
Details of some of the cases suggest that Zika poses the greatest risk to pregnant women and their unborn children in the first trimester.
One who lived in Brazil for her entire first trimester gave birth to a baby with severe microcephalyâ€”the birth defect linked to the virus. She had Zika symptoms in her seventh and eighth weeks, according to the report. The baby was born in late 2015 with an undersized head and signs of damage to its central nervous system. It had seizures, difficulty swallowing, and eye inflammation, and was discharged from the hospital with a feeding tube.Â Lab tests found evidence of Zika infection in the mother and the placenta of the baby.
The CDC wouldnâ€™t identify where she lived, but health authorities in Hawaii previously reported a similar case.
Another woman traveled to a Zika-affected region at the end of her first trimester and got sick then too. An ultrasound at 20 weeks showed severe brain damage, and an amniocentesis detected Zika virus. The woman terminated her pregnancy.
A third pregnant woman who had Zika symptoms at 17 and 18 weeks ultimately delivered a full-term healthy baby.
The CDC said it had received 14 reports of possible sexual transmission between Feb. 6 and 22, suggesting that is a more common mode of transmission than previously understood. Among the six cases that have been either confirmed or preliminarily confirmed, sexual contact occurred while the men were sick or just after they recovered. Two other cases have been excluded, and the remaining six are still under investigation, the CDC said.
The agency said it isnâ€™t known how long the virus persists in semen.
One study found it in the semen of one man 62 days after he was ill, but the virus wasnâ€™t infectious. Nor is it known whether sexual transmission of Zika poses a different risk of congenital infection than mosquito-borne transmission, the CDC said.