we are on it all tonight, and abc's linzie janis leads us off from louisiana tonight. linzie? >> reporter: david, we're here in prairieville, where a reported tornado rippled apart this golds gym. it took off the roof, then knocked out this entire side wall. you can see, the metal beam still hanging. this damage from one of multiple reported tornadoes across the gulf coast. >> oh look, it's going down! trying to touch down near new new orleans. >> a tornado warning in this area. take shelter now. extreme threat. >> reporter: severe weather spawning this massive water spout on lake pontchartrain. watch as two more form on the sides. the threat growing throughout the day. now, a particularly dangerous situation. officials in four states telling residents to be on extreme alert, for large, long-tracking tornadoes. major damage to downtown businesses in prairieville. incredibly, dozens of people inside this gold's gym, unharmed, as a reported tornado rips through. >> i started screaming, everybody get down, take cover. >> reporter: the entire side of the building sheered off. the

here's linzie janis. >> reporter: tonight, a drastic new recommendation for expecting couples. the cdc saying men returning from zika-affected countries should use protection with their partner for the entire pregnancy, or abstain altogether. but mosquitoes are still the primary way zika is spread. lizzie morales, a houston mother, got zika over the holidays while visiting el salvador. >> you have no strength, no energy, to do anything. not to even sit down. >> reporter: her symptoms subsided. but three deaths in colombia now blamed on zika. biologist matthew degennaro showing us a potential tool to fight the virus -- genetically modified mosquitoes. >> when you release the males, they go breed with females just of this species and render them sterile. >> reporter: so that knocks down the population? >> yes. >> reporter: david, in miami, they're spraying where there are to get rid of mosquitoes. >> dr. richard besser is just back from brazil. i want to get to the recommendation from the cdc, leading to the question, do we know how long the virus stays in your system? >> once yo

abc's linzie janis in florida. >> reporter: tonight, the state of florida ramping up its fight travel-related. the mosquito that causes zika virus is common in florida. >> reporter: the governor now declaring a state of emergency in five counties. so, are they prepared? florida has 20 million residents year. and right now, they have less than 1,000 kits to test for zika. the governor is requesting thousands more. do we think there are many people walking around with the have it? >> only 1 in 5 individuals who have been bitten and infected by a mosquito show any signs of symptoms. >> reporter: the symptoms of zika? fever, rash, joint pain and sometimes muscle pain and headache. in dallas this week, news that the virus was transmitted sexually has many officials concerned. and just tonight, another worry. the first case of zika infection from a blood transfusion reported in brazil. david, here at miami international airport, there are thousands of flights coming in countries flagged by the cdc. more than 100 flights from brazil alone. david? >> which is why they are taking precautions now in fl