Haiti is reporting its first cases of a mosquito-borne virus that is rapidly spreading in the Americas and is suspected of causing over 3,500 birth defects in Brazil.

Public Health Minister Florence Duperval Guillaume announced Friday that there have been five confirmed cases of the Zika virus in Haiti. She says they are all in the area of Port-au-Prince, the overcrowded capital.

Zika is a dengue-like virus that causes a mild illness in most people. But growing evidence links it to a rare condition known as microcephaly, in which newborns are born with small heads. Brazil has been experiencing the largest known Zika outbreak and a surge of birth defects.

Many Haitians live in shacks with little protection from mosquitoes.