What causes neonatal sepsis? Can it be cured?

Author: Wang Yajuan, Chief Physician, Children's Hospital, Capital Institute of Pediatrics

Reviewer: Zou Liying, Chief Physician, Beijing Obstetrics and Gynecology Hospital, Capital Medical University

Neonatal sepsis is a serious infectious disease in the neonatal period. Pathogens invade the blood, grow, multiply, and produce toxins, causing a systemic inflammatory response.

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The incidence of neonatal sepsis is relatively low, and with the improvement of medical standards, the mortality rate is also getting lower than before.

1. Which newborns are prone to sepsis?

Premature/low birth weight babies; premature rupture of membranes for too long, bacteria can easily enter the uterine cavity, leading to fetal infection; prolonged labor, or too many operations in the uterine cavity during delivery, will increase the chance of infection in the child.

Infections that occur in the womb are related to the mother. For example, if the mother has group B hemolytic streptococci or Escherichia coli colonization in the vagina, it is easy to transmit to the fetus. Early-onset sepsis occurs within 72 hours of birth. Group B hemolytic streptococci and Escherichia coli are the most common infections. Other infections, such as pustular or fungal infections in the mother, can also be transmitted to the fetus.

Newborns have low resistance, especially premature babies and babies with low birth weight. The living environment and sanitary conditions after birth are not good, or the hospitalization time is long, and there are many invasive operations, which can easily lead to the occurrence of neonatal sepsis. Most sepsis caused by postnatal infection is late-onset, usually occurring after 72 hours of birth. The pathogens of postnatal infection are more extensive, including Gram-negative bacilli and Gram-positive cocci. The most common Gram-negative bacilli are Escherichia coli, and the most common Gram-positive cocci are Staphylococcus aureus and coagulase-negative Staphylococci. If the infection occurs in the hospital, common pathogens are Acinetobacter baumannii, Klebsiella pneumoniae, etc.

2. What are the symptoms of neonatal sepsis?

Sepsis caused by intrauterine infection or intrapartum infection may occur in the child as soon as he is born, and the symptoms will be more serious. The child may suffer from suffocation and distress as soon as he is born, and his skin may be gray and cyanotic. His breathing and heart rate may be abnormal, and the extremities may be cold.

If the child is infected in the womb, the doctor may find the problem through regular prenatal checkups. The mother will show symptoms of infection, and by monitoring the fetus, the fetal heart rate and fetal movement may change, and growth and development may be affected, which will provide clinical clues.

The symptoms of sepsis caused by infection after a child is born may be mild or severe. For example, parents may find that their child has not been eating well, sleeps a lot, and has dark skin color. Jaundice may reappear or suddenly worsen because sepsis can destroy red blood cells and affect the metabolism of bilirubin. More serious symptoms may include bleeding spots, bruises, and convulsions on the body. Premature babies may experience cyanosis and respiratory arrest, and their body temperature may not be high or may even be low. Full-term babies may have a fever.

Neonatal sepsis is caused by bacteria and fungi entering the blood, which may affect all organs in the body. The most serious complication is purulent meningitis, which affects the central nervous system and has an impact on intelligence, limb activities, etc.; it affects the digestive system and may cause liver abscesses, necrotizing enterocolitis, etc.

Depending on the severity of sepsis and the time of discovery, the symptoms may be inconsistent. Generally speaking, the symptoms of neonatal sepsis are not typical. If the child does not eat, cry, move, gain weight, or have a temperature rise, seek medical attention immediately.

3. How to treat a newborn baby diagnosed with sepsis?

The diagnosis of sepsis first requires a medical history and physical examination. If sepsis is suspected, corresponding auxiliary examinations should be performed, such as routine blood tests, pathogen detection, and blood culture to see if there is any growth of pathogenic microorganisms. Molecular biology methods, immunological methods, and metagenomic testing are all diagnostic methods for identifying pathogens. If there are symptoms of purulent meningitis, a lumbar puncture is also required.

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After the pathogen is identified, the corresponding antibacterial drugs are used to treat bacterial and fungal infections. They need to be administered intravenously, and the amount and course of treatment must be sufficient. The other thing is nutritional support. Try to feed orally. If the mental response is really poor, the stomach is bloated, and you can't eat, you may need intravenous nutritional supplements. Then there is nursing and symptomatic supportive treatment.

As for neonatal sepsis, with the improvement of medical level and the increase of effective antibacterial drugs, the cure rate is still quite high. Children with more serious sepsis and more complications may also be in danger of life, but this situation is not very common.