The World Health Organization declared the Zika outbreak linked to thousands of birth defects in Brazil an international health emergency on Feb. 1, although much about the virus remains unknown.

"Test results of the patient hospitalised with a suspected Zika virus last week in Presov, eastern Slovakia, were positive," Cislak told reporters.

"The patient is in good health and does not require further treatment," he said.

Much remains unclear about the virus, including whether it causes microcephaly in babies, a condition defined by unusually small heads that can result in developmental problems.