1516. Early-Onset Neonatal Sepsis Due to Haemophilus influenzae

BACKGROUND: Haemophilus influenzae causes serious invasive disease across all ages, but has not been widely described in neonatal early-onset sepsis (EOS). EOS, likely caused by organisms acquired from the mother, can lead to significant morbidity and mortality, particularly for preterm infants. There are reports of increasing ampicillin resistance in H. influenzae. We describe a case series of EOS due to H. influenzae at our institution. METHODS: Neonatal H. influenzae EOS was identified based on positive sterile site cultures at <72 hours of life in infants hospitalized at an Intermountain Healthcare (IHC) facility from 2007–2017. Demographics, clinical and microbiologic data were obtained through an IRB-approved electronic chart and microbiology review. RESULTS: Twelve neonates with H. influenzae EOS were identified over 11 years. Nine were preterm (<37 weeks); five were extremely preterm (<28 weeks). Eight had low birth weight (<2,500 g); five had very low birth weight (<1,500 g). Most (66%) mothers were primigravida; median maternal age was 24.5 years. Only four (33%) mothers had prolonged rupture of membranes (>24 hours). All infants had signs and symptoms of sepsis within 24 hours of birth. The majority (10/12) had a blood culture positive for H. influenzae from the time of delivery. Two infants had negative delivery blood cultures but a H. influenzae-positive placental culture. No infant had > 1 day of bacteremia. One H. influenzae isolate was serotype b, one serotype c and one non-typeable, but most isolates (9/12) were not serotyped. Only one isolate produced a β-lactamase. All infants were empirically started on ampicillin and gentamicin at delivery. Nine infants underwent lumbar puncture, two were suggestive of meningitis but cultures were negative. Five infants developed interventricular hemorrhage and six required vasoactive medications. No infant died. CONCLUSION: H. influenzae is an infrequent but important cause of neonatal EOS. H. influenzae EOS occurred in infants with known risk factors, including prolonged rupture of membranes, prematurity, and low birth weight. Recognition of H. influenzae as a potential pathogen in EOS has implications for the use of empiric antibiotic therapy particularly ampicillin, in septic neonates. DISCLOSURES: All authors: No reported disclosures.