In the latest Case Record of the Massachusetts General Hospital, premature newborn boy was admitted to the hospital because of respiratory distress. On his sixth day of life, sudden clinical deterioration and multiorgan system failure developed, and he died on his seventh day. An autopsy was performed.
Neonates with very low birth weight (less than or equal to 1500 g), such as this patient, are at increased risk for bacterial or viral sepsis. Presenting signs of neonatal sepsis are nonspecific and protean and include temperature instability, lethargy, apnea, jaundice, respiratory distress, rashes, poor perfusion, irritability, and poor feeding.
• What are common pathogens associated with neonatal sepsis?
Bacterial pathogens include gram-negative organisms (Escherichia coli, klebsiella), streptococcus, staphylococcus species, or listeria. Causes of viral sepsis include enterovirus, adenovirus, and HSV.
• How do inborn errors of metabolism typically present?
Inborn errors of metabolism in newborns consist of a heterogeneous group of disorders most of which have similar clinical presentations. Pregnancy and delivery are usually uncomplicated; neonates are often healthy at birth, but metabolic imbalances may develop during the first week of life, in association with poor feeding, vomiting, excessive sleepiness, and lethargy. The inborn errors of metabolism that present uniquely and dramatically in newborns include organic acidemias, primary lactic acidoses, urea-cycle defects, disorders of carbohydrate metabolism, disorders of amino acid metabolism, and fatty-acid oxidation defects. Some infants with organic acidemias have distinctive urinary odors (e.g., the odor of maple syrup in maple syrup urine disease or the odor of sweaty socks in isovaleric acidemia).
Morning Report Questions
Q: What are the characteristics of neonatal HSV infection?
A: Both HSV-1 and HSV-2 are common in pregnant women and can cause neonatal infection. Neonatal HSV infection occurs in approximately 1 in 3200 deliveries and may present with three syndromes that frequently overlap: involvement of skin, eyes (e.g., keratoconjunctivitis or choriodoretinitis), mouth, or a combination; neurologic infection (meningo-encephalitis); and disseminated infection. Disseminated infection is difficult to diagnose because nonspecific signs of severe organ failure predominate. Diagnosis is often delayed, and infection with HSV is often discovered only at autopsy.
Q: What are the risk factors for transmission of HSV to a newborn?
A: An estimated 85% of cases of neonatal HSV are acquired at birth. Risk factors for transmission include the presence of HSV in the birth canal, prolonged rupture of membranes, vaginal delivery, and the use of fetal monitors. Cesarean section is associated with a reduced risk of transmission from the mother. The highest risk to the neonate (risk of transmission, 30 to 50%) is primary maternal infection close to delivery, leading to a high quantity of virus and an absence of type-specific HSV antibody passed to the neonate. The risk of transmission from mothers who have recurrent infection at the time of delivery is much lower (risk of transmission, <3%).