The Zika virus, which is potentially linked to a birth defect, will likely spread to every country in the Americas except for Chile and Canada, a division of the World Health Organization said.
The Pan American Health Organization said Monday that the virus has already spread to 21 countries and territories including the United States.
The organization believes the virus will spread to most of the countries in North and South America because citizens in those countries haven’t built up immunity to Zika.
The main mode of transmission of the virus is the Aedes mosquito, which can be found in every country in the region except Chile and Canada.
The statement comes as the Centers for Disease Control and Prevention is urging pregnant women or women trying to get pregnant to not travel to about 21 countries and territories in North and South America.
There have been no cases of U.S. transmissions, but some states have reported infected people in several states who returned from visiting one of the affected countries. Infections have been reported in Texas, Florida and Illinois and a report of a birth defect linked to the virus in Hawaii.
The virus mainly causes a rash, fever and other symptoms. But it could be linked to a birth defect called microcephaly in which the baby is born with a smaller head.
More studies are needed to determine the link, and research is under way to better understand how the virus affects babies, the Pan American Health Organization said.
The organization added that Zika can be transmitted through blood, but that is an “infrequent mechanism. Standard precautions are already in place for ensuring safe blood donations and transfusions should be followed.”
The group added that there is no evidence Zika can be transmitted to babies through breast milk.
A good way to avoid Zika is to prevent mosquito bites through long-sleeved shirts and using physical barriers such as screens and closed doors and windows, the organization said.
