>> I feel good.>> Top ranked golfer Jason Day, four time major champion Rory McIlroy, and Today Show host Savannah Guthrie. Just a few of the high profile names sitting out of this year's Olympics. Worries over the spread of the Zika virus in Brazil sparking concerns worldwide over traveling to Rio.
But health officials say the impact may not be as dire as feared. Cooler weather coupled with efforts to eliminate mosquito breeding grounds have cut Zika infection rates by about 90% across the country since February. That's welcome news for not just residents, but for the hundreds of thousands visiting the games.
Rio Brazil correspondent Paulo Prada.>> Because of the cooler temperatures and because of the lower mosquito counts right now, it's really unlikely that that many people would actually get infected with the virus. According to calculations that epidemiologists have made in recent weeks and months, out of the 500,000 foreigners who are expected to come to Rio, at the most, for the games.
Possibly 15 of those might actually get infected, and maybe only 3 of those would even show symptoms.>> Still, statistics like that may not paint a full picture of the risks. Zika, which can cause a debilitating birth defect known as microcephaly in babies, only presents minor symptoms in most adults and often goes undiagnosed.
And there's still many aspects of the virus scientists do not understand, including how it causes complications and why some populations seem to have been disproportionately affected.>> By far the hardest hit region in Brazil, and anywhere really, is the northeast of the country. There are other places in Brazil, and indeed around South America, that have conditions very similar to Brazil's northeast in terms of hot temperatures, high mosquito counts in the hot months, dense populations with really poorly planned urban settings.
But they didn't get the same type of outbreak. Epidemiologists are trying to figure out why exactly that part of the country was hit so hard and other regions haven't.>> More than 1,400 babies have been diagnosed with microcephaly in northeastern Brazil. By contrast, in the state of Rio which has nearly twice the population, only 72 cases had been confirmed.