On the same day researchers announced their findings, Florida health officials microcephaly-1115772-2/?utm_source=Futurity+Today&utm_campaign=50660fb00f-March_4_20163_4_2016&utm_medium=email&utm_term=0_e34e8ee443-50660fb00f-206349089" target="_blank">said they confirmed one new case of Zika virus infection in Miami-Dade, raising the countywide total to 23 people, most in the state. Reports have documented traces of the virus in the brains of affected babies who died soon after birth, and in fetal brain tissue after abortion.
Zika infection has been linked to numerous cases in Brazil of the birth defect microcephaly in babies, a condition defined by unusually small heads that can result in developmental problems. But they said it does identify where the virus may be inflicting the most damage in developing fetuses. Zika virus has been spreading through the Americas since 2015.
Colombia has reported the largest number of cases in Latin America after Brazil, where the outbreak was first detected previous year and where 1.5 million Zika cases have been reported.
The samples came from people who became sick after traveling to countries where the mosquito-borne virus is circulating, health officials said.
The Colombian Collaborative Network on Zika, the group of researchers that diagnosed the children, is also investigating several more possible cases of microcephaly with a suspected link to Zika, Nature reported.
They suggest a name for these effects: Zika virus congenital syndrome. The worst time to be exposed to the Zika virus is between the sixth and 35th week of pregnancy.
"This is a model that we and others can use to further study the link experimentally", he said.
"I think the study is going to be incredibly important to the understanding of how microcephaly develops", said Jeanne Sheffield, a maternal health expert at Johns Hopkins University who did not participate in the study, in a university announcement.
There were fresh signs on Friday of Zika-linked microcephaly cases outside Brazil. However, these findings do not show definitive proof about the connection between Zika virus and microcephaly.
The Centers for Disease Control and Prevention (CDC) confirmed a case of Zika virus in a man from Missouri who traveled to Haiti, a known area of Zika transmission.
Forty-two of those women, as well as 16 women who did not test positive for Zika, underwent ultrasounds to examine their fetuses.
Scientists from Johns Hopkins University, Emory University and Florida State Universityfound that the virus likely targets a type of cell that actively divides in the human brain between the second and fourth month of gestation.
They also discovered that these infected cells replicate the Zika virus, posing potential treatment problems, and that the virus is directly interfering with cell growth and function.
Dr. Guo-li Ming of Johns Hopkins University, another lead study author, said researchers can now explore questions like how Zika infects the cells.