The World Health Organization called the virus outbreak an international public health emergency Tuesday. Here's what you need to know about the virus.
1. The first cases of the latest Zika virus outbreak were reported in Brazil in May 2015, according to World Health Organization. The virus typically causes fever, rash, joint pain and red eyes. The illness is typically mild and can present symptoms for as long as one week, according to the Centers for Disease Control and Prevention.
2. The virus, transmitted by mosquitos, has been linked to microcephaly, a birth defect that causes babies to have abnormally small heads compared to other babies of the same age and sex. One such case was confirmed by the CDC in Hawaii.
3. There is no vaccination or treatment for Zika. The best way to prevent the virus is to stay away from the mosquitos that cause it, according to the WHO.
4. Zika was confirmed in the U.S. as early as Jan. 27, when Arkansas officials confirmed a case in their state. These were followed by a case in Massachusetts and six cases in Texas. The virus will likely keep spreading, according to the WHO — likely to "all countries and territories of the region where Aedes mosquitoes are found."
5. Zika can be transmitted sexually. The CDC confirmed the first sexually transmitted case in the U.S. on Feb. 2.