Enteral L-arginine supplementation for prevention of necrotizing enterocolitis in very low birth weight neonates: a double-blind randomized pilot study of efficacy and safety.

BACKGROUND: Necrotizing enterocolitis (NEC) is the most common acquired gastrointestinal disease in premature infants and has high mortality and morbidity. Endothelial nitric oxide is an important regulator of vascular perfusion and is synthetized from the amino acid L-arginine. Hypoargininemia is frequently observed in preterm neonates and may predispose them to NEC. Our objective was to determine the effect of enteral L-arginine supplementation on the incidence and severity of NEC in very low birth weight (VLBW) neonates. MATERIALS AND METHODS: We conducted a parallel blind randomized pilot study, comprising VLBW neonates with birth weight ≤1500 g and gestational age ≤34 weeks. VLBW neonates were randomly assigned to receive enteral L-arginine supplementation (1.5 mmol/kg/d bid) between the 3rd and 28th day of life or placebo. Diagnosis and classification of NEC were done according to modified Bell's criteria. RESULTS: Eighty-three neonates were randomized to the arginine (n = 40) or placebo (n = 43) group. No adverse effects were observed in neonates receiving L-arginine supplementation. The incidence of NEC stage III was significantly lower in the arginine-supplemented group (2.5% vs 18.6%, P = .030). CONCLUSIONS: Enteral L-arginine supplementation of 1.5 mmol/kg/d bid can be safely administered in VLBW neonates from the 3rd to the 28th day of life. Enteral L-arginine supplementation appears to reduce the incidence of stage III NEC in VLBW infants. Larger studies are needed to further evaluate the effect of L-arginine supplementation in preventing NEC in VLBW infants.

Consecutive Serratia marcescens multiclone outbreaks in a neonatal intensive care unit.

BACKGROUND: This report describes 3 consecutive outbreaks caused by genetically unrelated Serratia marcescens clones that occurred in a neonatal intensive care unit (NICU) over a 35-month period. METHODS: Carriage testing in neonates and health care workers and environmental investigation were performed. An unmatched case-control study was conducted to identify risk factors for S marcescens isolation. RESULTS: During the 35-month period, there were 57 neonates with S marcescens isolation in the NICU, including 37 carriers and 20 infected neonates. The prevalence rate of S marcescens isolation was 12.3% in outbreak 1, 47.4% in outbreak 2, and 42% in outbreak 3. Nine of the 20 infected neonates died (45% case fatality rate). A total of 10 pulsed field gel electrophoresis types were introduced in the NICU in various times; 4 of these types accounted for the 9 fatal cases. During outbreak 3, a type VIII S marcescens strain, the prevalent clinical clone during this period, was detected in the milk kitchen sink drain. Multiple logistic regression revealed that the only statistically significant factor for S marcencens isolation was the administration of total parenteral nutrition. CONCLUSIONS: Total parenteral nutrition solution might constitute a possible route for the introduction of microorganisms in the NICU. Gaps in infection control should be identified and strict measures implemented to ensure patient safety.

Maternal genital colonization with Ureaplasma urealyticum promotes preterm delivery: association of the respiratory colonization of premature infants with chronic lung disease and increased mortality.

BACKGROUND: Infection of the chorioamnion with Ureaplasma urealyticum has been associated with low birth weight. Respiratory tract colonization in preterm infants has been associated with the development of chronic lung disease (CLD). The purpose of the present study was to determine the frequency of colonization of the mother's vagina and the preterm infant's respiratory tract and to associate U. urealyticum with premature birth and with development of CLD in the newborn. METHODS: The present prospective study involved 126 mothers with preterm delivery and 125 mothers with full-term delivery, as well as their offspring. Vaginal secretion specimens were obtained from each mother before delivery. Rhinopharyngeal secretion or tracheal lavage specimens were collected after the birth of each premature and full-term infant and then periodically during hospitalization. RESULTS: Vaginal Ureaplasma colonization occurred among 36.5% of mothers with preterm delivery and among 38% of mothers with full-term delivery. The rate of vertical transmission was 33% and 17% for mothers with preterm delivery and mothers with full-term delivery, respectively. The transmission rate for infants, according to birth weight, was as follows: 60%, for infants with a birth weight of <1000 g; 50%, for infants with a birth weight of 1000-1500 g; and 15.3%, for infants with a birth weight of > or =1500 g (P=.001). The median gestational age of preterm infants born to colonized mothers was 28.5 weeks, and that of preterm infants born to noncolonized mothers was 32 weeks (P<.0001). The median birth weight of colonized preterm infants was 1135 g, and that of noncolonized infants was 1670 g (P<.0001). Twenty-four percent of preterm infants and 10% of full-term infants were colonized with U. urealyticum. Of colonized preterm infants, 27% developed CLD, compared with 9% of noncolonized infants (P=.03). Mortality was significantly higher among colonized preterm infants (P=.003). CONCLUSIONS: The rate of vertical transmission is highest among preterm infants with a birth weight of <1500 g. Vaginal colonization with Ureaplasma organisms is associated with premature delivery. Colonization of the respiratory tract of infants is associated with the development of CLD and with increased mortality.