Mothers should continue to breastfeed their babies in Zika outbreak areas because there is no evidence that the virus can be passed to children in this way, the World Health Organization (WHO) said Thursday.
"In light of available evidence, the benefits of breastfeeding for the infant and mother outweigh any potential risk of Zika virus transmission through breast milk," WHO said.
The rising numbers of children born with abnormally small brains and heads that have been accompanying the Zika outbreak in the Americas has raised concerns about breastfeeding.
However, although genetic material from the Zika virus has been found in breast milk, there have been no reported cases of transmission through mother's milk, the UN health agency wrote in Geneva.
There have also been no cases in which babies of Zika-infected mothers developed complications after birth, WHO noted.
Zika has been spotted in more than 30 countries, most of them in the Americas. The virus usually causes only mild symptoms including fever.
Scientists have acknowledged a link between Zika and microcephaly head malformations, but they have yet to find out how one causes the other, and why some outbreak countries have seen a microcephaly surge while others have not.
The virus is mainly spread by mosquitoes, but there are also a few known cases of sexual transmission.
The Czech Health Ministry on Thursday reported the first two confirmed cases of the Zika virus in the country.
A woman had been infected with the Zika virus on a trip to the Dominican Republic, while a man had caught the virus on the Caribbean island of Martinique, Health Minister Svatopluk Nemecek said in Prague.