The causes of viral infections in newborns are usually the following: 1, contact transmission: the child was just born, relatives and friends have come to visit, some relatives will not only pick up the newborn, but also a few kisses, at this time the adults will carry the virus to the baby, such as herpes simplex virus. 2, through the respiratory tract: parents who have influenza, did not pay attention to isolation and protection, the flu virus is easily transmitted to the baby. 3, mosquito bites: If the summer did not do a good job of repelling mosquitoes, the baby was bitten by mosquitoes will also be infected with some kind of virus, such as the B brain virus. 4, improper parental care: resulting in newborns catching cold, at this time due to low immunity, the virus will also take advantage of the situation.