On Dec. 31, 2015, the National IHR Focal Point (NFP) of the United States of America notified the Pan-American Health Organization (PAHO) and the World Health Organization (WHO) of the first laboratory-confirmed case of Zika virus infection in the Commonwealth of Puerto Rico, an unincorporated territory of the United States. The patient is a resident of Puerto Rico and had no travel history outside the island in the three months prior to the onset of illness. A blood sample obtained from the patient tested positive for Zika viral RNA by reverse transcription polymerase chain reaction (RT-PCR).Epidemiological investigations are ongoing to determine the source of exposure and detect possible additional cases. Vector control efforts by the Department of Environmental Health, including inspections to identify mosquito breeding sites, is underway. The public is being urged to take preventive measures to avoid mosquito bites.The PAHO/WHO present the following frequently asked questions (FAQs) about Zika virus infection and Zika fever.