When Brazil began its "war" against the Zika virus epidemic, the mosquito was described as enemy No 1. But, with less than two months to go before the Olympics, the health crisis has now become a battle of public opinion as authorities scramble to convince the world that Rio is safe to host the Games.While experts argue over whether the 500000 expected visitors could spread Zika to new areas, the World Health Organisation has bowed to international pressure, saying it will reassess the dangers of hosting the Olympics in Rio in August."Given the level of international concern, I have decided to ask members of the Zika emergency committee to examine the risks of holding the Olympic Summer Games as scheduled," said Dr Margaret Chan, the organisation's director-general, on Friday night. This was in response to a letter from US Senator Jeanne Shaheen.Pregnant women with Zika have up to 13% risk of microcephaly: studyPregnant women infected with the Zika virus during the first trimester have a risk of up to 13 percent that their infant will be born with the microcephaly birth defect, a new study says.Zika a 'threat to Games'This year's Rio Olympics should be postponed because of Zika.The WHO said initially there was no "public health justification" for altering the Games after academics claimed the Olympics posed an "unnecessary risk" for the spread of the virus.But Amir Attaran, a law and medicine professor at the University of Ottawa, who is among those leading the campaign to postpone or move the Games from Rio, accused the WHO of acting "irresponsibly".He is a co-author of an open letter by 150 international experts to the organisation, which last week argued the body was rejecting such calls due to its partnership with the International Olympic Committee."The organisation is in a terrible conflict of interest by being partner and adviser to the Olympics and then having to turn around and assess the risk of the Olympics," Attaran said."This is not how a regulator is supposed to act; there is not supposed to be a partnership or collaborative arrangement between the regulator and the regulated - never," he said."A handful of infected humans travelling from Rio to Lagos, Kinshasa and Mumbai would be at great risk of seeding new epidemics. All it takes is one traveller," Attaran said.Brazilian authorities have insisted the number of Zika cases among Olympic visitors is likely to be in single figures but reassurances have failed to assuage international concern.The Zika virus was first identified in Brazil a year ago and is a relatively mild illness with flu-like symptoms for most patients.But it has been linked to microcephaly in newborns if their mothers contracted it during pregnancy, and a rare neurological condition, Guillain-Barré syndrome, which can cause paralysis and death.Brazilian scientists said it would have already spread to other countries during Carnival, when a million tourists visited Rio."All measures have been taken," said Health Minister Ricardo Barros."There is no greater risk for the spread of Zika virus at the Olympics." ..