-- The Zika virus outbreak continues spread throughout the Western Hemisphere, including in wide swaths of Central and South America, and concerns are growing for pregnant women because the mosquito-borne virus has been linked with a serious birth defect called microcephaly, characterized by an abnormally small head and brain.
Here are the latest updates about the outbreak, which the World Health Organization has deemed a "global health emergency."
Aruba and Bonaire Added to Travel Advisory Watch List
Two new countries, Aruba and Bonaire -- both of which are islands off the coast of Venezuela -- have been added to the travel advisory list by the U.S. Centers for Disease Control and Prevention.
That brings the total number of countries or territories on the list to 32, including Puerto Rico, Brazil, Guatemala and Mexico. The CDC is warning pregnant women to reconsider traveling to any of these countries with ongoing Zika virus transmissions.
In addition, anyone who travels to these countries are advised to use mosquito repellent for three weeks after travel to prevent spreading the disease through mosquitoes.
Colombia Could Be Next Epicenter for Zika Virus, Health Officials Warn
As the Zika virus spreads through the Americas, the Pan American Health Organization said Colombia could be hard hit by the virus. The country has already been found to have ongoing transmission of the virus, and health officials said they expect another half a million Zika cases in the next few months.
Dr. Marcos Espinal of the Pan American Health Organization said the group is tracking 2,000 pregnant women who have been diagnosed with the Zika virus to see if there is a correlation between the virus and the birth defect microcephaly. The virus has already been associated with a rise in the microcephaly in Brazil. The birth defect is characterized by an abnormally small head and brain, which can lead to significant developmental delays.
Officials said they expect the women to give birth in June and they will look for signs of an increase in microcephaly.
What Does the Virus Do?
Common symptoms of the Zika virus include fever, rash, joint pain and conjunctivitis, according to the CDC. Approximately one in five people infected with the virus show symptoms. Severe complications from the virus that require hospitalization are rare, according to the CDC.
The virus has been associated with the birth defect microcephaly.
The CDC is also investigating if a rare paralysis syndrome called Guillain-Barre is related to the virus. The syndrome is an immunological reaction that can occur after other viral or bacterial infections.
How Is It Transmitted?
The virus is transmitted mainly through the bite of the Aedes aegypti species of mosquito. This is the same type of mosquito that spreads dengue fever. The Aedes albopictus species has also been identified as a potential carrier.
Before the current outbreak, the virus had been found mainly in tropical settings in Africa, Southeast Asia and the Pacific Islands. An outbreak of the disease in Brazil led to an alert by the Pan American Health Organization last May.
Health officials have also reported rare cases of transmission through blood transfusions and through sexual contact, including one case in Dallas, Texas.