Zika continues to spread rapidly.

The World Health Organisation has declared the mosquito-borne Zika virus to be an international public health emergency. The decision comes as the disease - linked to thousands of birth defects in Brazil - continues to spread rapidly.Experts believe as the virus spreads from Brazil, other countries in the Americas are also likely to see cases of babies with Zika-linked birth defects. The Pan American Health Organisation says that Zika has now spread into 24 nations and territories in the Americas. The disease has no vaccine and no known cure. Protective measures suggested by health experts include control of mosquito populations and the prevention of mosquito bites. More about Zika in this interview with Dr. Zeid Househ study as Specialist of Pathology at St George hospital - Sydney .