>>Related: CDC advises pregnant women not to travel to these countries
To date, 31 cases of the Zika virus have been confirmed in the United States spread across 12 states. All have been related to travel.
“This is a whole new ballgame,” Dr. Lyle Petersen, director of the Division of Vector Borne Diseases at the CDC told The Atlanta Journal-Constitution on Wednesday. “We have more questions than answers.”
In Texas, a man who'd traveled to Brazil apparently infected his sexual partner with the virus on his return to the U.S., the CDC confirmed this week. That potentially opens up a new route of transmission. Four out of five people who contract the virus get it through mosquito bites from two different types of the insect, which are commonly found in the Southern United States.
>>Related: How to prevent Zika virus
About four out of five people get the Zika virus and have no symptoms. The most common symptoms are joint pain, fever and rash. Pregnant women or those who think they are pregnant are advised by the CDC not to travel to countries that are experiencing an outbreak of the disease. For a list of countries visit http://wwwnc.cdc.gov/travel/page/zika-travel-information.