Brazil: Growing fears among pregnant women as Zika virus spreads The Zika virus, a mosquito-borne disease suspected of causing serious birth defects, is expected to spread to all countries in the Americas except Canada and Chile, the World Health Organization said. With the sting of a mosquito bite and a fever, many pregnant women may not know that they caught the Zika virus -- until it strikes their unborn child. IMAGES AND SOUNDBITES of a mother 16 weeks into a pregnancy with her second child