Neonatal Sepsis in Newborns
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Neonatal sepsis is a serious bloodstream infection occurring in infants within the first 28 days of life. It is classified as early-onset (EOS, within 72 hours of birth) or late-onset (LOS, after 72 hours to 28 days). Early-onset sepsis is primarily caused by organisms acquired from the maternal genital tract during labor and delivery, with Group B Streptococcus (GBS) and Escherichia coli being the most common pathogens. Late-onset sepsis may be acquired from the birth canal, hospital environment (nosocomial), or community. Neonatal sepsis remains a leading cause of morbidity and mortality in newborns, particularly premature infants, and symptoms are often subtle and non-specific, making a high index of clinical suspicion essential.
Key takeaways
- Neonatal sepsis is a serious bloodstream infection occurring in infants within the first 28 days of life.
- Duration: Uncomplicated bacteremia treated with IV antibiotics: 10-day course with hospital stay of 10-14 days. Meningitis: 14-21 days of IV antibiotics depending on organism. Complicated courses with shock, organ failure, or need for surgical intervention: weeks to months of hospitalization. Long-term neurodevelopmental follow-up is recommended for all survivors, especially preterm infants.
- Go to ER if: ANY fever (rectal temperature >100.4F/38C) in a baby under 28 days old — do not call first, go immediately
- No vaccine currently available
Symptoms
How It Presents by Age
0-72 hours (early-onset)
Early-onset sepsis often presents within the first 24 hours with respiratory distress as the predominant finding. The neonate may have tachypnea, grunting, apnea, temperature instability, and poor perfusion. GBS and E. coli are the most common organisms. Pneumonia frequently accompanies EOS. Maternal risk factors (GBS colonization, chorioamnionitis, prolonged ROM, prematurity) help guide the evaluation.
Risk level: Very high — mortality 3-5% in term infants, 15-30% in preterm infants
72 hours - 7 days (late early-onset)
May represent a transition between early and late onset. Organisms can be from maternal or environmental sources. Presentation includes worsening feeding tolerance, temperature instability, lethargy, and cardiovascular instability. Meningitis should be considered, and lumbar puncture is important.
Risk level: Very high
7-28 days (late-onset, community)
Late-onset sepsis in term infants at home presents with fever (most reliable sign), poor feeding, lethargy, and irritability. GBS (late-onset type III), E. coli, and Listeria are important organisms. Urinary tract infection is a common source. Any febrile neonate in this age group requires full sepsis evaluation including blood, urine, and CSF cultures.
Risk level: High — all febrile neonates require evaluation
7-28+ days (late-onset, NICU)
Nosocomial late-onset sepsis primarily affects premature infants in the NICU. Coagulase-negative Staphylococci (associated with central lines), S. aureus, gram-negative rods, and Candida are common pathogens. Signs include feeding intolerance, increased apnea/bradycardia, temperature instability, and abdominal distension. Central line-associated bloodstream infection (CLABSI) is a major source.
Risk level: Very high — especially in VLBW infants (<1500g)
Treatment
Empiric IV antibiotics
Started immediately when sepsis is suspected — before culture results. For EOS: ampicillin plus gentamicin is the standard empiric regimen. For LOS (community): ampicillin plus gentamicin, or ampicillin plus cefotaxime if meningitis is suspected. For LOS (nosocomial/NICU): vancomycin plus an aminoglycoside or anti-pseudomonal beta-lactam, depending on local resistance patterns.
Duration-guided antibiotic therapy
If blood cultures are negative at 36-48 hours and the infant is clinically well, antibiotics may be discontinued (per AAP guidelines for EOS). For culture-proven sepsis: 10 days for bacteremia without meningitis, 14-21 days for meningitis (duration varies by organism). GBS meningitis requires 14 days minimum; gram-negative meningitis requires 21 days.
Supportive NICU care
Respiratory support ranging from supplemental oxygen to mechanical ventilation. IV fluid resuscitation for poor perfusion. Temperature regulation in isolette. Close monitoring of vital signs, glucose, electrolytes, and acid-base status. Blood product transfusions as needed.
Vasopressor support
Dopamine, epinephrine, or norepinephrine may be needed for septic shock that is refractory to fluid resuscitation. Hydrocortisone may be added for vasopressor-resistant shock (relative adrenal insufficiency in preterm infants).
Source control and targeted therapy
Removal of infected central venous catheters for CLABSI. Adjustment of antibiotics based on culture and sensitivity results. For Candida sepsis (common in VLBW infants), fluconazole or amphotericin B is used. Repeat blood cultures to document clearance.
Home Care
- There are NO home remedies for neonatal sepsis — this is a medical emergency
- Any fever or signs of illness in a newborn under 28 days requires immediate emergency medical evaluation
- Do not wait to see if symptoms improve — bring the baby to the ER immediately
- After hospital discharge, monitor the baby closely for any recurrence of symptoms
- Follow all prescribed medication schedules and follow-up appointments
- Practice good hand hygiene — wash hands before handling the newborn
When to Worry
Go to the ER if:
- ANY fever (rectal temperature >100.4F/38C) in a baby under 28 days old — do not call first, go immediately
- Hypothermia (temperature <97.7F/36.5C) that does not improve with warming
- Baby is limp, floppy, or unresponsive
- Breathing pauses (apnea), grunting, or labored breathing
- Skin is mottled, pale, bluish, or gray
- Baby refuses to feed and has decreased urine output (fewer than 3 wet diapers in 24 hours)
- High-pitched or weak cry that is different from normal
- Seizure-like movements
- Rapidly worsening condition of any kind
Call your doctor if:
- Any fever (>100.4F/38C) in a baby under 28 days old — this always requires IMMEDIATE evaluation, go to the ER
- Temperature below 97.7F/36.5C that persists despite warming efforts
- Baby is eating significantly less than usual
- Increased sleepiness or decreased responsiveness
- New or worsening jaundice
- Any breathing changes — faster, noisy, or pauses in breathing
Keep an eye on:
- Newborn feels warmer or cooler than usual
- Baby is feeding less than half of normal amounts or refusing feeds
- Baby is unusually sleepy, limp, or difficult to wake for feeds
- Breathing seems faster, noisier, or more effortful than normal
- Baby is more irritable than usual and difficult to console
- Skin looks pale, mottled, or grayish
- Jaundice is worsening after initial improvement
- Baby just "does not seem right" — trust your parental instinct
Prevention
- Universal maternal GBS screening at 36-37 weeks gestation
- Intrapartum antibiotic prophylaxis for GBS-positive mothers during labor
- Prompt treatment of chorioamnionitis with antibiotics during labor
- Clean delivery practices and appropriate perinatal care
- Strict hand hygiene in the NICU — the single most important measure for preventing nosocomial LOS
- Central line insertion and maintenance bundles to prevent CLABSI
- Minimizing duration of central venous catheters and invasive devices
- Breast milk feeding — protects against both sepsis and NEC in premature infants
- Antibiotic stewardship — avoid prolonged empiric antibiotics without proven infection
- Fluconazole prophylaxis for extremely low birth weight infants in NICUs with high Candida rates
Contagion & Incubation
Incubation
Early-onset sepsis: symptoms typically present within the first 12-48 hours of life, and by definition within the first 72 hours (some definitions use 7 days). Late-onset sepsis: presents after 72 hours of life up to 28 days (or up to 90 days in some definitions for preterm infants). NICU-acquired infections may present at any time during the hospitalization.
Contagious for
Neonatal sepsis itself is not contagious in the traditional sense. However, the causative organisms may be transmitted between patients in the NICU through contaminated hands, equipment, or surfaces if infection control measures are not followed.
Duration
Uncomplicated bacteremia treated with IV antibiotics: 10-day course with hospital stay of 10-14 days. Meningitis: 14-21 days of IV antibiotics depending on organism. Complicated courses with shock, organ failure, or need for surgical intervention: weeks to months of hospitalization. Long-term neurodevelopmental follow-up is recommended for all survivors, especially preterm infants.
Frequently asked questions
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Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Related Illnesses
Bottom line
Neonatal Sepsis in Newborns is treatable with appropriate medical care. Seek emergency care if any fever (rectal temperature >100.4f/38c) in a baby under 28 days old — do not call first, go immediately.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.