Zika virus 'spreading explosively,' WHO leader says - CNN

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Residents are seen past a public service announcement banner against the spread of Aedes mosquitoes, a carrier for the Zika virus, at a residential block at Aljunied Crescent neighbourhood in Singapore on August 29, 2016. Singapore on August 28 confirmed 41 locally transmitted cases of the Zika virus, which can cause deformities in unborn babies, and said more infections are likely. / AFP / ROSLAN RAHMAN (Photo credit should read ROSLAN RAHMAN/AFP/Getty Images)

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MCALLEN, TX - APRIL 14: A city environmental health worker displays literature to be distrubuted to the public on April 14, 2016 in McAllen, Texas. Health departments, especially in areas along the Texas-Mexico border, are preparing for the expected arrival of the Zika Virus, carried by the aegypti mosquito, which is endemic to the region. The U.S. Centers for Disease Control (CDC), announced this week that Zika is the definitive cause of birth defects seen in Brazil and other countries affected by the outbreak. (Photo by John Moore/Getty Images)

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WHO estimates 3 million to 4 million cases of Zika possible in Americas in 12-month period

(CNN) —

The Zika virus “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.”

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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.”

Some 80% of those infected with the Zika virus don’t even feel sick, and most who do have relatively mild symptoms such as a fever, rash, joint pain or pink eye. But there are major worries about the dangers pregnant women and their babies face.

Chan said that, where the virus has arrived, there’s been a corresponding “steep increase in the birth of babies with abnormally small heads and in cases of Guillain-Barre syndrome.” Having small heads can cause severe developmental issues and sometimes death. Guillain-Barre is a rare autoimmune disorder that can lead to life-threatening paralysis.

The WHO’s Dr. Bruce Aylward cautioned there was no definitive link between Zika and these disorders but sees a legitimate reason for concern. The Centers for Disease Control and Prevention’s Dr. Anne Schuchat said there is a “strong” suggestion they are connected.

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While studies are underway to determine any links, millions of people live in areas with real fears about what this virus can do.

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After first being detected in 1947 in a monkey in Uganda, Zika was most often found along the equator from Africa into Asia. Nine years ago, new cases popped up in islands in the Pacific Ocean.

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Last year, the virus made its way to the Americas – with devastating results.

Since Brazil made its first discovery of Zika in May, the number of cases there and elsewhere in the Americas has grown exponentially. The virus had been thought to be relatively harmless over the long term, but that view changed late last year.

Health authorities began to suspect a connection between Zika and neurological ailments, especially in fetuses and newborns. Brazil alone has reported more than 4,000 cases of microcephaly – a neurological disorder resulting in the births of babies with small heads – in infants born to women infected with Zika while pregnant.

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“Zika is not a new virus,” the CDC’s Schuchat said. “But what we are seeing in the Americas is new.”