Problems linked to the virus are now found in children, teenagers and older adults.
British Olympians are reported to be worried about the disease with the Rio Olympics approaching.
The WHO says it is taking immediate action to expedite research on the causal relationship between the outbreak of the virus and the growing rate of infant birth defects in Brazil.
Scientists announced they've used CRISPR to introduce and disseminate infertility in wild mosquito populations.
Researchers say ivermectin, a drug designed to fight parasitic worms, could also help fight the spread of malaria.