HEALTH : Zika virus 'spreading EXPLOSIVELY - WHO leader says

The Zika virus is "is now spreading explosively"
in the Americas, the head of the World Health
Organization said Thursday, with another official
estimating between 3 million to 4 million infections in
the region over a 12-month period.
"The level of concern is high, as is the level of
uncertainty," Dr. Margaret Chan, WHO's director-
general, told her organization's executive board
members. "We need to get some answers quickly."
Five things you need to know about Zika
The lack of any immunity to Zika and the fact that
mosquitoes spreading the virus can be found most
"everywhere in the Americas" -- from Argentina to the
southern United States -- explains the speed of its
transmission, said Dr. Sylvain Aldighieri, an official with
the WHO and Pan American Health Organization.
Aldighieri gave the estimate for Zika infections
(including people who do not report clinical symptoms)
based on data regarding the spread of a different
mosquito-borne virus -- dengue. He acknowledged the
virus is circulating with "very high intensity."