A baby may be sick at the time of birth or become sick any time during the first week. The first symptoms may be subtle, but as the bacteria multiply the baby can become quite sick very fast. If an infection is found and treated early, the baby will do very well. If the baby is not treated until the later stages of the infection, the baby may be very sick and need intensive care to recover. Sometimes newborns catch a viral infection.
Viruses cause colds, flu, and some diseases such as herpes and chickenpox.
A virus may travel from the placenta into a baby's bloodstream before birth. Or the baby may be exposed to a virus in the birth canal during delivery. Occasionally, a newborn catches a viral infection after birth by being exposed to someone with a cold. Newborns can get sick very fast. Babies respond very quickly to antibiotics.