Brazil says Zika virus outbreak worse than believed

Brazil's top health official said on Monday that the Zika virus outbreak is proving to be worse than believed because most cases show no symptoms, but improved testing should allow the country to get a better grip on the burgeoning public health crisis.

In Brazil, believed to be the country hit hardest by Zika, the outbreak has sparked fear especially among pregnant women after local experts linked the virus to thousands of cases of  microcephaly, or abnormally small heads and underdeveloped brains, in newborns.

"Eighty percent of the people infected by Zika do not develop significant symptoms. A large number of people have the virus with no symptoms, so the situation is more serious that we can imagine," Health Minister Marcelo Castro said in an interview.

Castro said Brazilian researchers are convinced that Zika is the cause of the 3,700 confirmed and suspected cases in Brazil of microcephaly in newborns. Ninety percent of children born with the condition will have retarded mental and physical development, experts say.

Brazilian biomedical research centers are joining forces with U.S. counterparts to try to find a Zika vaccine in record time, Castro said. A partnership between the U.S. National Institutes of Health and Brazil's Butantan Institute will seek to develop a vaccine by adding a gene to an existing one for dengue, he said.

The Brazilian government suspects the virus was brought to Brazil during the 2014 soccer World Cup by a visitor from Africa or Oceania where Zika is endemic. An estimated 1.5 million Brazilians have caught Zika, a virus first detected in Africa in the 1947 and unknown in the Americas until it appeared in May in the poverty-stricken northeastern region of Brazil. The Pan-American health Organization said the virus has since spread to 24 countries and territories in the hemisphere.

On Monday (i.e. 01.02.2016), the World Health Organization declared the Zika outbreak to be a global emergency, a decision that should help fast-track international action and research priorities.

Source: http://www.reuters.com/article/health-zika-brazil-exclusive-idUSKCN0VA33F