( CNN ) -- Enterovirus D68 has swept through 30 states since mid-August . What sets the virus apart from many others in the same family is its vicious symptoms : Instead of just causing a summer cold , it sends children to the hospital -- where they often end up in the intensive care unit , struggling to breathe . David Nash from Tucker , Georgia , is one of those children . At first his parents , Rachel and Rodney Nash , were n't too alarmed when David came down with a cough , runny nose and low-grade fever . But then the 3-year-old got sick very quickly . David was in the first wave of children hit with Enterovirus D68 . The virus struck early in states such as Georgia , where children headed back to school last month , but it then spread to states such as New York and Connecticut , where school began after Labor Day . `` There 's no doubt the opening of schools has facilitated the transmission of Enterovirus D68 , '' says Dr. William Schaffner , an infectious disease specialist at Vanderbilt University Medical Center . What parents should know . The Nashes shared with CNN the day-to-day story of their son 's illness , hoping it might help families whose children have been recently diagnosed with what one pediatrician calls a `` frightening '' virus . August 11 . A healthy David and his big brother , Benjamin , start school . August 24 . David develops a cough , runny nose and low-grade fever . His parents are n't too worried as it seems like a regular cold . August 25 . The Nashes become more concerned . Their little ball of energy who loves flying around the house as Batman does n't want to play . That night , he wheezes as he sleeps . His parents wake him to give him puffs from an inhaler prescribed for his seasonal allergies . August 26 . David 's breathing gets worse . `` You could see him trying to pull the air in , '' Rachel Nash recalls . `` His nostrils flared as he inhaled , and you could see the muscles in his neck and collarbone working extra hard . '' Rodney Nash adds , `` I remember as a kid my goldfish jumped out of the bowl . That 's how he looked to me -- like a goldfish gasping for breath . '' The Nashes take David to the emergency room at Children 's Healthcare of Atlanta . His oxygen saturation rate is 86 % . Healthy children 's oxygen saturation is around 97 % . The doctors give David oxygen through his nose . Every two hours he gets nebulizer treatments , which are commonly used to treat asthma , to try to unclog his airways . David hates the mask and is n't cooperative . David 's saturation rate goes up to 88 % , but that 's not enough . He 's admitted to the hospital . August 27 . In addition to the oxygen and breathing treatments , David gets an oral steroid to help shrink the swelling in his airways . Even then , David is still wheezing . `` It sounded like air going through a balloon -- where you pinch the balloon and hear the squeaking sounds , '' his father says . Doctors try a `` shaker vest . '' Blasts of air shake the vest , which loosens up mucus caught in the lungs . David does the shaker vest treatment every three hours , but he 's still not better . August 28 . At 4 a.m. , a nurse says David is finally responding to the treatments . His breathing , which had been quick and shallow , is slowing down . The nebulizer treatments go from every two hours to every four . He still does n't like them , but he does n't protest as much as he did before . At 8 a.m. , David is taken off the oxygen and allowed to play . Nurses watch to see if he can breathe OK while riding a bike . If he ca n't , it means more time in the hospital . David does fine on the bike , and his oxygen saturation level reaches 94 % around lunchtime . He 's discharged from the hospital . August 29-31 . For the first two days back at home , David does inhaler treatments every four hours . He wheezes a bit , but he 's pretty much back to his old self -- energetic and playful . September 16 . David has an appointment with his pediatrician , Dr. Betsy John . She gives him a clean bill of health . David 's journey with Enterovirus D68 is fairly typical , says Dr. Mary Anne Jackson , division director of infectious diseases at Children 's Mercy Hospital in Kansas City , Missouri . Many children , however , get sick even faster . David was ill for about two days before he had to be hospitalized , but many of Jackson 's patients have gone from healthy to severely ill in just a day , and they arrive at the hospital barely able to breathe . `` These kids were really struggling . Many ca n't even speak a sentence , '' she says . `` It 's frightening . '' Her advice : If D68 has made its way to your community , and your child has asthma , or even , like David , just a history of allergies or occasional breathing difficulties , call your pediatrician and ask if there 's anything you can do to protect your child .
Enterovirus D68 is sending children with breathing problems to the hospital . David Nash fell ill in August with typical enterovirus symptoms . The 3-year-old was hospitalized but has since recovered .