A case study of a stillborn baby whose Brazilian mother was infected with Zika raises suspicions that the virus may be capable of doing more damage to fetal tissue than previously thought, researchers said on Thursday, according to Reuters. The study showed the baby's brain was absent, a condition known as hydranencephaly. Instead of tissue, the brain cavities were filled with fluid. The baby also had abnormal pools of fluid in other parts of its body. The case, published in the journal PLOS Neglected Tropical Diseases, is the first to link Zika virus with damage to fetal tissues outside the central nervous system. So far, birth defects associated with the rapidly spreading Zika virus have been almost entirely confined to Brazil and linked to microcephaly, a condition in which babies are born with abnormally small heads. Brazil has confirmed more than 580 cases of microcephaly and is investigating more than 4,100 suspected cases.