Singapore reported another big batch of Zika virus cases Friday, bringing its total count in just a week to 189, and World Health Organization officials said the spread of the virus definitely still constitutes a global health emergency.

Zika's apparent quick spread out of Latin America back to Asia and Africa has WHO officials worried. They have no idea if the virus will spread as explosively as it has in the Americas, and they cannot predict if it will cause a fresh wave of birth defects and side-effects such as the paralyzing Guillain-Barré syndrome.

Image: US-HEALTH-ZIKA-VIRUS
 
Miami-Dade mosquito control worker Carlos Vargas looks for the Aedes aegypti mosquito larvae at a home in Miami, Florida, on June 8. Of the 40 different types of mosquito found in Miami-Dade, the Aedes aegypti mosquito, or yellow fever mosquito, is responsible for transmitting diseases such as the Zika virus. Rhona Wise / AFP - Getty Images