This story was originally published on December 27, 2015.The outbreak of a mosquito-borne virus called Zika has prompted Brazilian officials to warn women against getting pregnant, CNN reports.The warning comes after a significant rise in cases of newborn microcephaly this year, with 2,400 cases in 2015 compared to 2014's 147. Microcephaly is a congenital neurological condition that presents with an abnormally small head and brain development issues. Premature death can also occur.The disorder has been linked to Zika after mothers of affected babies reported having virus-like symptoms, including a rash, mild fever, and headaches at the beginning of their pregnancies. In November, an autopsy of an affected infant revealed the presence of the Zika virus. Six states have now declared a state of emergency.According to Brazil's Health Ministry, the Zika outbreak has seen between half million and 1.5 million cases. The virus is transmitted by the Aedes aegypti mosquito, which is also present in small numbers in Texas, Hawaii, and Florida.Special precautions are being made as Rio de Janeiro prepares to host the Summer Olympics next summer, including the monitoring of pregnant women. For those who are considering starting a family, however, health officials are advising safety first."It's a very personal decision, but at this moment of uncertainty, if families can put off their pregnancy plans, that's what we're recommending," Brazilian pediatric infectologist Angela Rocha told CNN.