Cold sores are the result of the herpes simplex virus, also called HSV. Parenting and Child Health explains that cold sores are very common, infecting about 20 percent of children before the age of 5. Babies contract the virus during vaginal labor if the mother is infected or by exposure to infectious fluids from individuals with oral herpes. Individuals with a cold sore can hold a baby without infecting her by being cautious.
Cold sores are most often caused by the herpes simplex virus type one, or HSV-1. Herpes simplex virus type two, or HSV-2, is usually responsible for genital herpes. One strain of the virus can still infect other tissues of the body, meaning HSV-2 can cause oral herpes. Simply holding a baby will not lead to a baby contracting either type of the virus.
Knowing exactly when HSV is communicable, or when the individual is contagious, can be difficult. Many individuals do not realize they are infected with the virus. Parenting and Child Health points out that an individual is most likely to spread the virus when the cold sore has not healed entirely. During this time the cold sore may be a red, somewhat painful bump or it can be an oozing ulcer. A newly scabbed-over cold sore may still indicate the virus is active. KidsHealth warns that even though visible symptoms of a cold sore may not exist there is still the potential for contagiousness.
Parenting and Child Health states that saliva from an individual with a cold sore that has not yet healed is the most likely way the virus will be spread to a baby. The saliva of the infected individual can infect the baby when it enters the bloodstream or the mucus membranes, such as the soft tissues of the mouth, according to KidsHealth. Depending on the age, a baby may put his hands and anything else he can grasp into his mouth. Saliva or fluids from the cold sore can infect the baby when they reach the nasal passages, eyes and mouth.
Kissing an infant, sneezing, coughing or simply talking closely to the infant while holding it can potentially transport saliva from an infected individual to the baby. Sharing anything orally, such as a spoon, can increase the risk. When holding the baby, the individual's saliva has a small distance to travel to reach the baby.
Parenting and Child Health recommends individuals with cold sores keep contact with babies to a minimum to prevent spreading the virus. When this is unavoidable, the individual should take extra precautions to avoid transferring saliva or fluids from the cold sore to the baby. Kissing the baby on the cheeks or allowing the baby to put her hands into the individual's mouth can increase the risk of spreading oral herpes. Caregivers should wash their hands thoroughly with soap and water before handling or holding the baby. Cold sores should not be covered for long periods of time, as this can delay healing but temporarily covering the sore, especially if it is oozing, when holding the baby can reduce the risk of spreading the virus.