More than 3,100 pregnant women in Colombia have Zika virus - government

A health worker sprays mosquito repellent on a pregnant woman's arm, during a campaign to fight the spread of Zika virus in Soledad municipality near Barranquilla, Colombia, in this February 1, 2016 handout photo supplied by the Soledad Municipality. REUTERS/Aleydis Coll/Soledad Municipality/Handout via Reuters

BOGOTA (Reuters) - More than 3,100 pregnant Colombian women are infected with the mosquito-borne Zika virus, President Juan Manuel Santos said on Saturday, as the disease continues its rapid spread across the Americas.

Brazil is investigating the potential link between Zika infections and more than 4,000 suspected cases of microcephaly, a birth defect marked by an abnormally small head size that can result in developmental problems. Researchers have identified evidence of Zika infection in 17 of these cases, either in the baby or in the mother, but have not confirmed that Zika can cause microcephaly.