Zika virus 'spreading explosively': WHO chief

Geneva (AFP) - The Zika virus is "spreading explosively" in the Americas and the region may see up to four million cases of the disease strongly suspected of causing birth defects, the World Health Organization warned Thursday.

As the number of suspected cases of microcephaly -- thought to be linked to the virus -- surged in Brazil, WHO head Margaret Chan said an emergency committee would meet Monday to determine whether the Zika outbreak amounts to a global health emergency.

Microcephaly causes babies to be born with an abnormally small head and brain.

Cases have soared in Brazil from 163 a year on average to more than 3,718 suspected cases since the outbreak, and 68 babies have died, according to the health ministry.

Colombia, Ecuador, El Salvador, Jamaica and Puerto Rico have warned women to avoid getting pregnant for the time being.

Jitters over Zika have spread far beyond the affected areas to Europe and North America, where dozens of cases have been identified among people returning from vacation or business abroad.
France -- which has logged five cases contracted by its citizens while travelling -- urged women not to travel to French overseas territories in South America and the Caribbean.
There is currently no treatment for Zika and a top US health chief warned Thursday the hunt for a vaccine could take years.
For decades after Zika's discovery in 1947, in a Ugandan forest from which it takes its name, the mosquito-borne virus was of little concern, sporadically causing "mild" illness in humans.
But the WHO's chief Chan told an assembly of member-states in Geneva the severity of the current outbreak was unprecedented.
"The situation today is dramatically different. The level of alarm is extremely high," she said, with Zika also possibly linked to a neurological disorder called Guillain-Barre syndrome.
"A causal relationship between Zika virus infection and birth malformations and neurological syndromes has not yet been established, but is strongly suspected," Chan said.

She told WHO members the virus "is now spreading explosively," in the Americas, where 23 countries and territories have reported cases.

The virus is not known to be transmitted person to person, but the US Centers for Disease Control and Prevention (CDC) said it was aware of one reported case of Zika through possible sexual transmission, and a second where the virus was found in semen two weeks after a man exhibited symptoms.

- 3 to 4 million cases -

Marcos Espinal, head of communicable diseases and health analysis at WHO's Americas office, said the region could see between three to four million cases -- a projection based largely on spread patterns of similar mosquito-borne diseases like dengue fever.