People think that when a newborn has an infection there must be symptoms of fever, unbeknownst to them, there are some patients who do not show fever even if they have a serious infection, which makes it easy for parents to relax their vigilance against the disease, such as some neonatal diseases such as neonatal pneumonia, neonatal sclerosis, neonatal sepsis, etc. There are even diseases that not only do not have fever, but also do not show a rise in body temperature, especially those suffering from neonatal sclerosis patients, some patients with severe infections have this condition, therefore, clinically, not every patient with infection will show fever. At present, neonatal infectious diseases still account for the highest morbidity and mortality rate among children in China. Bacteria and viruses are the most common pathogens, and there are intrauterine infections and postnatal infections, especially in some premature and immature infants with low immune function, which are more obvious, because neonatal infections can occur before, during, and after birth. Prenatal infections are mainly pathogens that infect the fetus via maternal blood through the placenta, and are the most common route, also known as intrauterine infections. Intrauterine infections are mainly chronic infections caused by viruses, which can lead to miscarriage, stillbirth, intrauterine growth retardation, congenital malformations and multi-organ damage such as hepatosplenomegaly, jaundice, anemia, thrombocytopenia and neurological damage after birth, also known as intrauterine infection syndrome, for the mother Intrauterine infection can be caused by upstream infection of pathogens in the reproductive tract of the mother and inhalation of contaminated amniotic fluid by the fetus. Because of the delicate skin of the newborn, pathogens can be transmitted through the trauma of the skin mucosa, respiratory tract, gastrointestinal tract and contact with family members carrying bacteria. Among postnatal infectious diseases, umbilical infection is one of the most common infectious diseases. Since the umbilicus is a new section, rich in blood oxygen, it is the best medium for bacterial reproduction, and if the stump of the umbilicus is not disinfected in time, it is most likely to cause umbilical infection. When the bacteria multiply in the umbilicus, it can cause the bacteria to multiply in the blood, resulting in neonatal sepsis and systemic toxicity, which affects the function of the child’s organs. If left untreated, the child’s life can be endangered at any time. Therefore, parents and medical personnel should strengthen the supervision of newborns to prevent the occurrence of neonatal infectious diseases.