Emergent Care / Stabilization:
All infants suspected of having neonatal pneumonia should be admitted to a neonatal intensive care unit (NICU) or special care nursery (SCN) and managed by a neonatologist. Infants should be stabilized with attention to airway, breathing, and circulation (ABCs). Umbilical venous and arterial lines and/or peripheral intravenous lines (IVs) should be established as indicated. Respiratory support ranging from supplemental oxygen (O2) up to mechanical ventilation should be provided as needed. Continuous pulse oximetry and arterial blood gas (ABG) / venous blood gas (VBG) sampling should be used to assess ventilation and oxygenation. Fluid and nutritional support should be provided.

Diagnosis Overview:
Neonatal pneumonia can be divided into early-onset (less than 72 hours of life) and late-onset (72 hours or more of life) presentations. Early-onset pneumonia generally occurs via hematogenous transplacental transmission or aspiration of infected amniotic fluid. Risk factors include prematurity, very low birth weight (VLBW) infants, galactosemia, and infants born to mothers with premature rupture of membranes (PROM), chorioamnionitis, group B Streptococcus (GBS) colonization, or intrapartum fever.

Late-onset neonatal pneumonia occurs from maternal vertical transmission or from nosocomial or other horizontal transmission sources (ill contacts). Risk factors include prematurity, VLBW infants, congenital airway abnormalities, mechanical ventilation, neurologic impairment, use of H2 blockers and proton pump inhibitors (PPIs), as well as prolonged hospitalization.

The most common presenting symptoms of neonatal pneumonia are often systemic and nonlocalizing, including respiratory distress, apnea, temperature instability, feeding intolerance, abdominal distention, vomiting, jaundice, and lethargy. Neonatal pneumonia can be caused by bacteria, viruses, parasites, or fungi. The most common bacterial pathogens are group B Streptococcus, Escherichia coli, Staphylococcus aureus, Chlamydia trachomatis, Listeria monocytogenes, Ureaplasma ureolyticum, Mycobacterium tuberculosis, Klebsiella spp, Pseudomonas spp, and Streptococcus pneumoniae. Viral causes include herpes simplex virus (HSV), cytomegalovirus (CMV), enterovirus, parechovirus, human metapneumovirus, respiratory syncytial virus (RSV), influenza (flu), parainfluenza (paraflu), adenovirus, and SARS CoV-2. Parasitic causes such as Toxoplasma gondii should also be considered. Fungal pathogens that are less common but are seen more often in extremely low birth weight (ELBW) infants and those receiving immunosuppressive agents may include Candida spp and aspergillosis.