The Zika virus that has been causing concerns about possible birth defects will likely reach nearly all countries in the Americas, the World Health Organization (WHO) said Monday.
The virus has already spread across 21 countries and territories on the American continents since the outbreak was noticed in Brazil last May, which marked the first time the virus was detected beyond Africa and Oceania.
The virus was expected to travel far because people had not been previously exposed to it and lacked immunity, but also because the Aedes mosquitoes that transmit it can be found in all of the Americas except Canada and continental Chile, the UN health agency said in a statement.
WHO's Pan American Health Organization "anticipates that Zika virus will continue to spread and will likely reach all countries and territories of the region where Aedes mosquitoes are found," it said.
Zika infections cause only slight symptoms such as fever or rashes in most adult patients.
However, Brazilian scientists have noted a link between higher rates of babies born with unusually small heads and the spread of Zika.
WHO recommends pregnant women should avoid mosquito bites. They should also consult doctors before planning a trip to countries where the virus circulates.
In addition, WHO said authorities should control mosquito populations by eliminating potential wet breeding grounds such as used tires, and by using larvicides.
People living in affected areas should also protect themselves from mosquitoes through clothing, nets, repellant and other measures.
As of January 24, the virus had spread to Barbados, Bolivia, Brazil, Colombia, the Dominican Republic, Ecuador, El Salvador, French Guiana, Guatemala, Guadeloupe, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname and Venezuela.