A cold and drinking problems – this is how infants often become infected with the RS virus. Completely harmless for adults, an infection can quickly become life-threatening for babies. If the state of health deteriorates following regarding three days, parents should take notice. If there is a high fever, the babies seem weak and breathing difficulties occur, coupled with a rattling cough, hospitalization may even be necessary. The reason: RS viruses primarily affect the lower respiratory tract, which can result in bronchiolitis or pneumonia.