Signs of respiratory syncytial virus in babies are similar to those of a cold, such as a runny nose and a cough, and they last a week or two, according to WebMD. Symptoms that require medical care include a high fever, breathing difficulty and a refusal to breastfeed or bottle-feed.
Respiratory syncytial virus, or RSV, is a contagious viral infection of the respiratory tract, as stated by WebMD. It affects babies under the age of 2 years. Respiratory syncytial virus infections in premature infants, infants with a weakened immune system and infants born with heart disease can lead to life-threatening complications.