Neonatal infections are infections of the neonate (newborn) acquired during prenatal development or within the first four weeks of life. Neonatal infections may be contracted by mother to child transmission, in the birth canal during childbirth, or after birth. Neonatal infections may present soon after delivery, or take several weeks to show symptoms. Some neonatal infections such as HIV, hepatitis B, and malaria do not become apparent until much later. Signs and symptoms of infection may include respiratory distress, temperature instability, irritability, poor feeding, failure to thrive, persistent crying and skin rashes. Risk factors include previous maternal infection, preterm delivery (< 37 weeks gestation) and premature rupture of membranes (breakage of the amniotic sac) which substantially increases the risk of neonatal sepsis by allowing passage for bacteria to enter the womb prior to the birth of the infant. Preterm or low birth weight neonates are more vulnerable to neonatal infection. While preterm neonates are at a particularly high risk, all neonates can develop infection. Maternal screening for intrapartum infections reduce the risk of neonatal infection. Pregnant women may receive intrapartum antibiotic prophylaxis for prevention of neonatal infection. Infant respiratory distress syndrome is a common complication of neonatal infection, a condition that causes difficulty breathing in preterm neonates. Respiratory distress syndrome can arise following neonatal infection, and this syndrome may have long-term negative consequences. In some instances, neonatal respiratory tract diseases may increase the susceptibility to future respiratory infections and inflammatory responses related to lung disease. Antibiotics can be effective for neonatal infections, especially when the pathogen is quickly identified. Instead of relying solely on culturing techniques, pathogen identification has improved substantially with advancing technology; however, neonate mortality reduction has not kept pace. In industrialized countries, treatment for neonatal infections takes place in the neonatal intensive care unit (NICU). Neonatal infection can be distressing to the family and it initiates concentrated effort to treat it by clinicians. Research to improve treatment of infections and prophylactic treatment of the mother to avoid infections of the infant is ongoing.
Signs and symptoms Signs and symptoms of infection include respiratory distress, temperature instability, irritability, failure to thrive, and skin rashes.
Etiologies Early-onset sepsis (EOS), defined as onset of symptoms within 72 hours of life, is generally caused by transmission of pathogens from the female genitourinary system to the fetus. Pathogens can infect the fetus via vertical transmission (direct transmission through the placenta in utero) or infection during delivery as fetus passes through vaginal canal. Late-onset sepsis (LOS), defined as onset of symptoms after 72 hours of life, is generally caused by transmission of pathogens from the environment after delivery. Infants requiring intravascular catheters and other invasive procedures are at increased risk for developing LOS. There are many etiologies of neonatal infection, including bacterial, viral and fungal pathogens. The source of infectious bacteria and other pathogens is often the maternal gastrointestinal and genitourinary tract. Many of the maternal infections with these organisms are asymptomatic in the mother. Other maternal infections that may be transmitted to the infant in utero or during birth are bacterial and viral sexually transmitted infections. The infant's ability to resist infection is limited by its immature immune system. In addition, the immune system of the neonate may respond in ways that can create problems that complicate treatment, such as the release of inflammatory chemicals. Congenital defects of the immune system also affect the infants ability to fight off the infection.
Bacteria Bacteria found in the maternal gastrointestinal or gastrourinary tracts can commonly lead to neonatal infection. Bacterial infections may present as fetal distress at birth (including signs of tachycardia, temperature instability or difficulty breathing), neonatal sepsis, or neonatal meningitis. Infections that develop during NICU admissions are more commonly coagulase-negative staphylococci, especially in infants with indwelling catheters. Infections that develop one month after the birth of the infant are more likely due to gram-positive bacteria and coagulase positive staphylococci. ...
Group B streptococcus (GBS) Group B streptococcus (GBS), also named Streptococcus agalactiae, is a bacteria typically identified as the cause of the majority of early-onset infections in the neonate. GBS is an encapsulated gram-positive cocci that colonizes the gastrointestinal and genital tracts of pregnant women. Maternal infections are usually asymptomatic. This pathogen is vertically transmitted (transmitted directly from the mother's vagina into the infant's amniotic fluid after onset of labor). Due to the high prevalence of GBS, routine screening for the bacteria occurs during pregnancy. If the bacteria is found in the maternal GI / GU tract, mothers will receive IV antibiotic (usually penicillin or ampicillin).
Escherichia coli (E. coli) Escherichia coli is an encapsulated gram-negative bacilli that may cause neonatal infections due to its high prevalence in the GI and GU tracts of pregnant patients. With the advances in preventing group B streptococcus infections, β-lactam-resistant Escherichia coli infections have increased in causing neonatal deaths in very low birthweight and premature infants. Common complications of neonatal E.coli infection include neonatal sepsis and neonatal meningitis.
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