A team of researchers led by a Florida State University scientist announced on Friday that they may have found “an entry point” for establishing a causal link between the Zika virus and microcephaly, a birth defect in which a baby is born with an abnormally small head and an underdeveloped brain.
On the same day researchers announced their findings, Florida health officials said they confirmed one new case of Zika virus infection in Miami-Dade, raising the countywide total to 23 people, most in the state. Broward has seen six confirmed Zika infections.
All of Florida’s 48 confirmed Zika infections were acquired by travelers outside the country, state health officials said. Four of the cases are pregnant women, though state health officials declined to identify the counties where the expectant mothers reside or the places where they traveled.
The Florida Department of Health’s Zika Virus Information Hotline has assisted 909 callers since its Feb. 12 launch. The hotline number is 855-622-6735.
Pregnant women are considered to be at greatest risk from the virus because of a strongly suspected link between an outbreak of Zika in Brazil and a concurrent spike in microcephaly.
The new lab research, published in the journal Cell Stem Cell, provides strong evidence that Zika virus targets human embryonic neural cells for infection — increasing the death of those cells, and stunting brain development. But the study also raises questions, including whether Zika virus infects neural cells in adults.
The number of pregnant women returning to the United States with Zika infections acquired abroad has been rising, according to the CDC. As of Feb. 17, the CDC had received reports of nine pregnant travelers with laboratory-confirmed Zika virus. Ten additional reports of Zika virus among pregnant women are currently under investigation. No Zika virus–related hospitalizations or deaths among pregnant women were reported.
Pregnancy outcomes among the nine confirmed cases included two miscarriages, two elective terminations and three live births — two apparently healthy infants, and one infant with severe microcephaly, the CDC reported.
9 U.S. pregnant travelers with Zika virus infection identified as of Feb. 17
Two pregnancies are continuing without known complications, the CDC said.
Confirmed cases of Zika virus infection were reported among women who had traveled to one or more of the following nine areas with ongoing local transmission of Zika virus: American Samoa, Brazil, El Salvador, Guatemala, Haiti, Honduras, Mexico, Puerto Rico, and Samoa.
There is no vaccine for Zika virus, which generally causes a rash, fever and joint pain that can last from one week to 10 days, according to the CDC. The virus is primarily transmitted by mosquito bites, the CDC said infections have also been reported through blood transfusions and by men to their sexual partners.
Zika cases in Florida as of March 4 (all acquired outside state)
Number of Cases
Cases involving pregnant women*
Source: Florida Department of Health