For watchful parents, colds and the flu are an unwelcome tagalong to the holiday season. When a toddler's apparent cold doesn't improve after a few days, pediatric pulmonologist Dr. Stephen Levine suggests testing for respiratory syncytial virus (RSV). The Centers for Disease Control recently classified the respiratory infection as an epidemic in Louisiana, following a 40 percent increase in positive RSV tests over the last few months.
"It's been written that if you look at every child by the age of 2, he's had some exposure to RSV," he says. "RSV is big right now, but there's [also] some combination of rhinovirus and adenovirus that the entire Gulf Coast is suffering under."
RSV affects respiratory cells in the air passages known as the respiratory epithelium, changing the way air moves through the bloodstream. It's highly contagious and spreads through droplets, meaning a touch or a kiss easily transmits the virus.
"[Once contracted], the way [the virus] works is it balls up the mucus and respiratory cells that line the airways ... and some of these goopings of mucus and lung trash will partially block the opening to an air tube," Levine says. "That's what causes the wheezing and problems with oxygenation."
Though anyone can contract RSV, its complications mostly affect babies and toddlers who were born prematurely (at 32 to 35 weeks into a pregnancy) and children with congenital heart problems. When these children contract RSV, stuffy noses can turn quickly into hospital stays.
"The problem is if you have abnormal lung architecture, it's much worse than if you have normal lungs and RSV comes and infects you," Levine says. "Some children end up in the ICU or have to be ventilated (using a respirator to breathe for them) for a period of time because of this." The virus also is the leading cause of infant hospitalizations, according to the CDC.
RSV differs from the flu because several strains can be active in a given year, meaning researchers can't develop a standard annual vaccine. Generally only one type of influenza appears each winter, while researchers identify two or more strains of RSV annually, varying by geographic region and season. Their relative virulence makes an impact on the number of cases that have complications. Though Louisiana pediatricians see RSV cases every year, this year's strain seems especially aggressive, and the body's inability to develop a long-term immunity to the virus presents a challenge for doctors. Children can catch RSV more than once in a season, leaving them vulnerable to other health issues.
Levine's expertise comes from his work on a clinical trial for Synagis, a monthly injection of antibodies to stave off the infection. He says this treatment isn't perfect; it's expensive, necessitates monthly visits to the doctor's office and can, in most cases, only be given for two consecutive years. And like many viruses, RSV has no cure. Treatment focuses on confirming the presence of the virus through a rapid antibody test and alleviating symptoms.
The best defense against RSV, Levine says, is to "get out in front of it." Wash hands for at least 30 seconds with soap and warm water before touching your child to minimize the danger of introducing the virus to them, especially if you often come in contact with other children such as in a day care setting. Be aware of any risk factors your child may have and call your pediatrician if you see rapid breathing, retraction (where the lips pull in while drawing breath) or respiratory distress. Also, consider asking your pediatrician about the RSV injection if you're aware of any significant health issues.
Fortunately, when otherwise healthy adults get RSV, it rarely causes anything more serious than cold-like symptoms like rhinitis. Larger bronchial passages in adult lungs can't be blocked as easily, so the same kinds of issues don't occur. But parents should be vigilant for signs of RSV in their children, especially infants and toddlers.
"Although you have an idea of what class of patients tend to [develop complications], you never know exactly who is going to be that type of patient until they show you that they are," Levine says. "You don't wait until [your child is] so sick that they whisk [him or her] upstairs to the ICU, or they can tell right away [he or she is] not oxygenated. You don't want to get here on the tail end of a bad deal."