BLITZER: The Zika virus is spreading explosively across the Americas, according to the World Health Organization. Twenty-three countries and territories are now on high alert for the potentially deadly virus. Transmitted by mosquitoes, it's blamed for a sometimes crippling birth defect. Some doctors are even going so far as to tell women to postpone getting pregnant. CNN's Shasta Darlington spoke to the mother of one of the 4,000 babies affected across Brazil.</s>SHASTA DARLINGTON, CNN CORRESPONDENT (voice-over): She was so excited, but the birth of her second child left Rafaela Oilveira more alone than she could have imagined. At three months, Luis Phillippe (ph) has a big appetite, just like her first baby, but he was born with a small head and brain damage, microcephaly. "People here react like he's got some contagious disease," she says. "People look at him when they're in the street." There was no warning. Doctors only detected the disorder after Luis Phillippe was born. "What gives me strength is the love I feel for him," she says. Luis Phillippe will need to be cared for his entire life.</s>DARLINGTON (on camera): So she's doing this three times a week right now, taking her son to physical therapy, and yet she goes back to work in March. It's not clear how she's going to do this. And she's the only person in her family who has a job.</s>DARLINGTON (voice-over): Here, in the state of Farnamoko (ph), we've seen the heartache and the financial burden this is putting on families. More than 4,000 cases of newborn microcephaly have been reported in Brazil since Zika was detected less than a year ago. A third of them are here, where babies and moms face endless jabs and tests. Dr. Angela Hosha (ph), one of the first to make the link between Zika and microcephaly.
Zika Virus Spreading; Zika Virus Linked to Birth Defect.