Did you know that the average toddler gets about six colds per year? Jammed largely into the winter months, a child's cold can seem like one constantly runny nose from October to March. Fortunately, most colds are annoying but otherwise lead to no harm—other than running down the household tissue supply!
Not so with a particular virus called "RSV" or respiratory syncytial virus. This virus may start as a bad cold, but can quickly move down into the lungs in our most vulnerable infants, causing a life-threatening illness.
History of RSV
First discovered in chimpanzees with bad colds, RSV was originally called chimpanzee coryza agent. Once discovered in infants as well, it was renamed respiratory syncytial virus after the changes in the respiratory cells (seen under the microscope) brought about by infection with this agent. Though RSV has always been around and is found worldwide, there are predictable epidemics each year, corresponding to our winter through early spring seasons.
RSV alone is responsible for between 75,000 and 125,000 hospitalizations per year in the United States. Though this is a drop in the bucket compared to the total number of RSV infections worldwide. Most hospitalized children are very young, between two and five months of age. Unlike other viruses (chicken pox for example), RSV can be caught repeatedly, though subsequent infections are milder, acting more like a bad cold with a particularly long-lasting cough. And it is a hearty germ, able to survive for hours on a countertop.
Signs of RSV
So how can a parent tell when a child has RSV? There is no surefire way, as viruses can be unpredictable and variable in the way they present, but a "typical" pattern is as follows. Two to eight days after exposure to the virus, symptoms of a cold develop: runny nose (usually an impressively gooey one), a variable fever, and decreased appetite. Not uncommonly, the ears are infected as well.
In approximately 50 percent of infected children, the virus then moves down the respiratory tract into the lungs, creating an entirely different set of symptoms. The hallmark symptom is difficulty breathing. At this point, the infection is called bronchiolitis or pneumonia. Infants will begin to breathe faster and will work harder to get those breaths in and out. Parents can often see the muscles of the belly or chest "tugging" for air. Obvious wheezing can also be heard as the illness progresses into the lungs. Many children are no longer able to drink, since breathing is more important and taking up most of their energy. Infants may begin to grunt or look blue around the lips—an obvious medical emergency. Worst of all, a very small or young infant can get so tired from the work of breathing that he stops breathing altogether.
Though even a full-term, healthy infant may end up very ill, the hardest hit by this virus are the most vulnerable: infants born prematurely, those who have chronic lung disease, those with congenital heart disease, or the immuno-compromised.