Epidemiology of neonatal infections: experience during and after hospitalization

Prenatal Exposure to Proton Pump Inhibitors and Risk of Serious Infections in Offspring During the First Year of Life: A Nationwide Cohort Study

INTRODUCTION AND OBJECTIVE

Proton pump inhibitor (PPI) use in children increases the risk of infections, prompting inquiry into the impact of prenatal PPIs exposure on serious infections in offspring. As a research gap in this area exists, this study aimed to address it by assessing the association between prenatal PPIs exposure and serious infections in infants during their first year of life.

METHODS

Using the French health insurance data warehouse (SNDS) (2013-2018), we conducted a retrospective cohort study on singleton, full-term liveborn non-immunocompromised infants, stratified by PPI use during the first three months of life (early-life use). Proton pump inhibitor dispensing in ambulatory care settings during pregnancy defined exposure. Outcomes concerned any serious infections in offspring aged between 3 and 12 months. Adjusted odds ratios (aORs) were estimated using logistic regression with multivariable models to control for potential confounders.

RESULTS

Of the 2,485,545 infants included, 497,060 (23.3%) were prenatally exposed to PPIs and 97,767 (4.6%) had PPI use during the first three months of life. Prenatal PPI exposure was associated with serious infections in offspring (aOR, 1.09 [95% CI, 1.07-1.10]) in infants without early-life PPIs use. No association was found for infants with early-life PPI use (aOR, 1.05 [95% CI, 1.00-1.11]). Gastrointestinal infections were the sole site with persistent significance.

CONCLUSION

Prenatal PPI exposure is common and is not associated with a major risk of serious infections in infants during their first year. However, even after adjusting for several confounding factors, a weak association remains, especially in infants without early-life PPI use. While offering reassurance, adherence to clinical guidelines is still crucial.

In Utero Exposure to Antibiotics and Risk of Serious Infections in the First Year of Life

INTRODUCTION AND OBJECTIVE

Given the high prevalence of antibiotic prescription during pregnancy in France and previous studies suggesting an increased risk of infection in offspring with such exposures, our study aimed to investigate the association between prenatal exposure to systemic antibiotics and serious infections in full-term infants during their first year of life.

METHODS

We conducted a retrospective population-based cohort study on singleton, full-term liveborn non-immunocompromised infants, using the French National Health Data System (SNDS) between 2012 and 2021. Systemic antibiotic dispensing in ambulatory care settings during pregnancy defined the exposure. Outcomes concerned serious infections (i.e., infections requiring hospitalization) in offspring identified between 3 and 12 months of life, hence excluding infections of maternal origin. Adjusted odds ratios (aORs) were estimated using logistic regression with multivariate models to control for potential confounders.

RESULTS

Of 2,836,630 infants included, 39.6% were prenatally exposed to systemic antibiotics. Infants prenatally exposed to antibiotics had a higher incidence of serious infections compared with unexposed infants {aOR 1.12 [95% confidence interval (95% CI) 1.11-1.13]}. Similar associations were observed according to the timing of exposure during pregnancy, antibiotic class, and site of infections. The strongest association was observed when infants were prenatally exposed to three or more antibiotic courses during pregnancy [aOR 1.21 (95% CI 1.19-1.24)]. Limitations include residual confounders, such as genetic susceptibility to infections and the role of the underlying pathogen agent.

CONCLUSION

Prenatal exposure to systemic antibiotics is very common and is associated with a weak yet significant associations with subsequent serious infectious events during the first year of life. While our study revealed associations, it is important to note that causation cannot be established, given the acknowledged limitations, including potential confounding by indication.

Drug-induced fetal and offspring disorders, beyond birth defects

Studies on drug utilization in western countries disclosed that about nine over ten women use at least one or more drugs during pregnancy. Determining whether a drug is safe or not in pregnant women is a challenge of all times. As a developing organism, the fetus is particularly vulnerable to effects of drugs used by the mother. Historically, research has predominantly focused on birth defects, which represent the most studied adverse pregnancy outcomes. However, drugs can also alter the ongoing process of pregnancy and impede the general growth of the fetus. Finally, adverse drug reactions can theoretically damage all developing systems, organs or tissues, such as the central nervous system or the immune system. This extensive review focuses on different aspects of drug-induced damages affecting the fetus or the newborn/infant, beyond birth defects, which are not addressed here.

Infections in the NICU: Neonatal sepsis

Neonatal infections remain an important cause of neonatal morbidity and mortality worldwide. Neonatal sepsis is a systemic infection that can be classified as early-onset or late-onset pending the timing of presentation. The pathophysiology and causative pathogens of neonatal sepsis vary, with early-onset sepsis being associated with a vertically transmitted infection from mother to neonate versus late onset sepsis being commonly associated with nosocomial infections. The signs and symptoms of neonatal sepsis mimic those associated with prematurity, making timely diagnosis difficult for treating clinicians. The management of neonatal sepsis is centered around obtaining adequate culture data and initiation of broad-spectrum parenteral antibiotics. Controversies surrounding the management of neonatal sepsis include the administration of empiric antibiotics, given recent clinical studies associating early antibiotic use with clinical sequelae such as late-onset sepsis, necrotizing enterocolitis, and death in the preterm, low-birthweight infant population.

Galactokinase deficiency: lessons from the GalNet registry

PURPOSE

Galactokinase (GALK1) deficiency is a rare hereditary galactose metabolism disorder. Beyond cataract, the phenotypic spectrum is questionable. Data from affected patients included in the Galactosemias Network registry were collected to better characterize the phenotype.

METHODS

Observational study collecting medical data of 53 not previously reported GALK1 deficient patients from 17 centers in 11 countries from December 2014 to April 2020.

RESULTS

Neonatal or childhood cataract was reported in 15 and 4 patients respectively. The occurrence of neonatal hypoglycemia and infection were comparable with the general population, whereas bleeding diathesis (8.1% versus 2.17-5.9%) and encephalopathy (3.9% versus 0.3%) were reported more often. Elevated transaminases were seen in 25.5%. Cognitive delay was reported in 5 patients. Urinary galactitol was elevated in all patients at diagnosis; five showed unexpected Gal-1-P increase. Most patients showed enzyme activities ≤1%. Eleven different genotypes were described, including six unpublished variants. The majority was homozygous for NM_000154.1:c.82C>A (p.Pro28Thr). Thirty-five patients were diagnosed following newborn screening, which was clearly beneficial.

CONCLUSION

The phenotype of GALK1 deficiency may include neonatal elevation of transaminases, bleeding diathesis, and encephalopathy in addition to cataract. Potential complications beyond the neonatal period are not systematically surveyed and a better delineation is needed.

Short-Term Outcomes and Mortality of Late Preterm Infants

BACKGROUND

Late preterm infants have increased rates of morbidity and mortality compared to term infants. Determining the risk factors in these infants leads to more comprehensive preventive and treatment strategies.

AIMS

Our aim was to analyse the morbidity rates such as respiratory system diseases, infections, congenital anomalies, hypoglycemia and hematologic abnormalities and mortality rates in a large group of patients at a referral center.

STUDY DESIGN

Retrospective cross-sectional study.

METHODS

Medical records of late preterm and term infants who were managed at the referral center were analysed.

RESULTS

41752 births were analysed in 3 years. 71.9% of all births were between 37-42 gestational weeks (i.e. term) and 16.1% were between 34-37 weeks (i.e. late preterm). Compared to term infants, late preterm infants had increased rates of short-term problems. The rate of mortality increased with decreased gestational age. The duration of hospitalization was significantly higher in the smallest late preterm infants.

CONCLUSION

This study demonstrated the need that late preterm infants who have higher risk for morbidity and mortality, compared to term infants require close monitoring. The rate of mortality and hospitalization increased with decreased gestational age.

Risk Factors for Neonatal Methicillin-ResistantStaphylococcus aureusInfection in a Well-Infant Nursery

Objective.

To determine risk factors for neonatal methicillin-resistantStaphylococcus aureus(MRSA) skin and soft-tissue infection in a well-infant nursery.

Design.

Case-control studies.

Setting.

A well-infant nursery in a nonteaching, community hospital.

Methods.

Case infants were newborns in the nursery who were born in the period November 2003 through June 2004 and had onset of MRSA skin and soft-tissue infection within 21 days after discharge from the nursery. Site inspections were conducted. Control infants were randomly selected male infants in the nursery during the outbreak periods. MRSA isolates were characterized with pulsed-field gel electrophoresis.

Results.

Eleven case infants were identified in 2 outbreaks: outbreak 1 occurred from November 18 through December 24, 2003, and outbreak 2 occurred from May 26 through June 5, 2004. All were full-term male infants with pustular-vesicular lesions in the groin. Inspection revealed uncovered circumcision equipment, multiple-dose lidocaine vials, and inadequate hand hygiene practices. In outbreak 1, case infants (n= 6) had a significantly higher mean length of stay than control infants (3.7 vs 2.5 days;P= .01). In outbreak 2, case infants (n= 5) were more likely to have been circumcised in the nursery (OR, undefined [95% CI, 1.7 to undefined]) and to have received lidocaine injections (OR, undefined [95% CI, 2.6 to undefined]). Controlling for length of stay, case infants were more likely to have been circumcised in the nursery (OR, 12.2 [95% CI, 1.5 to undefined]). Pulsed-field gel electrophoresis showed that 7 available isolates were indistinguishable from a community-associated MRSA strain (USA300-0114).

Conclusions.

Newborns in well-infant nurseries are at risk for nosocomial infection with community-associated MRSA strains. Reducing length of stay, improving circumcision and hand hygiene practices, and eliminating use of multiple-dose lidocaine vials should decrease transmission of community-associated MRSA strains in nurseries.

Risk factors for group B streptococcus colonization among pregnant women in Korea

OBJECTIVES

To identify obstetric and maternal factors related to Group B Streptococcus (GBS) colonization in pregnant women in Korea.

METHODS

The study was conducted between the years 2006-2008 in four hospitals, Cheil and Eulji hospital in Seoul, and Motae and Eulji hospital in Daejeon. We recruited 2,644 pregnant women between 35 to 37 weeks of gestation who had visited for antenatal care. Participants completed a questionnaire, and urine, vaginal and rectal specimens were obtained and cultured using selective broth media. After delivery, medical records were reviewed.

RESULTS

GBS colonization was significantly associated with hospital, age group, education, frequency of pregnancy, and premature rupture of membranes (PROM, more than 18 hours). After adjustment for other variables, Cheil hospital (odds ratio [OR], 2.05; 95% confidence interval [CI], 1.20-3.52), and the first pregnancy (OR, 2.32; 95% CI, 1.12-4.81) remained significant. History of vaginitis showed marginal significance (OR, 1.50; 95% CI, 0.98-2.29).

CONCLUSION

To prevent GBS infection of neonates, clinicians should be alert to the potentially higher risk of GBS colonization in pregnant women in their first pregnancy, and women with premature rupture of membranes (PROM) (18 hours+) or who have a history of vaginitis.

Neonatal infections in the developing world

An estimated one million newborns die from infections in developing countries. Despite the huge burden, high-quality data from community-based epidemiologic studies on etiology, risk factors, and appropriate management are lacking from areas in which newborns experience the greatest mortality. Several planned and ongoing studies in South Asia and Africa promise to address the knowledge gaps. However, simple and low-cost interventions, such as community-based neonatal care packages supporting clean birth practices, early detection of illness through use of clinical algorithms, and home-based antibiotic therapy in areas in which hospitalization is not feasible are already available and have the potential to bring about a drastic reduction in global neonatal mortality due to infections if they are scaled up to national level. Concerted collaborative action by national governments, health professionals, civil society organizations, and international health agencies is required to reduce neonatal mortality due to infections.

International perspective on early-onset neonatal sepsis

Infections are a major cause of neonatal death in developing countries. High-quality information on the burden of early-onset neonatal sepsis and sepsis-related deaths is limited in most of these settings. Simple preventive and treatment strategies have the potential to save many newborns from sepsis-related death. Implementation of public health programs targeting newborn health will assist attainment of Millennium Development Goals of reduction in child mortality.

Epidemiology of group B streptococcus in Korean pregnant women

Between January 2006 and May 2008, 2624 pregnant S. Korean women between 35–37 weeks gestation were screened for group B streptococcus (GBS). Resistance to antimicrobials was tested by disk diffusion and serotype determined using co-agglutination assays and microarray methods. Overall, 8% of pregnant women were colonized. Serotype III was the predominant serotype (43·8%), followed by serotypes V (20·3%), Ia (12·1%), and Ib (9·5%). GBS was frequently resistant to clindamycin (54·0%) and erythromycin (25·6%); 3·7% were resistant to cefazolin. More than three-quarters of serotype V were resistant to clindamycin or erythromycin or both, and 71% of serotype III were resistant to clindamycin but only 12% were resistant to erythromycin. GBS prevalence exceeded earlier reports by one-third. This is the first report of cefazolin resistance in Korea. These results underscore the need to establish screening measures and chemoprophylaxis guidelines regarding GBS infections in Korea.

Evaluation of microbiologic and hematologic parameters and E-selectin as early predictors for outcome of neonatal sepsis

CONTEXT

Early diagnosis of neonatal sepsis is mandatory. Various markers are used to diagnose the condition.

OBJECTIVE

To evaluate the diagnostic value of various clinical data and hematologic parameters, such as total leukocyte count, absolute neutrophil count, immature to total neutrophil ratio, and soluble E-selectin (sE-selectin) in identification and outcome of neonatal sepsis.

DESIGN

Newborn infants with a clinical diagnosis of sepsis in the neonatal intensive care unit at Mansoura University Children's Hospital during the period between July 2007 and December 2007 were eligible for study. In addition, 30 healthy neonates were included in the study. Complete hematologic and microbiologic laboratory investigations were performed, and serum E-selectin was measured.

RESULTS

Plasma sE-selectin levels were significantly higher (P < .001) in infected infants (mean [SD], 156.9 [77.0] ng/mL) than in noninfected (mean [SD], 88.8 [47.1] ng/mL) and healthy infants (mean [SD], 8.67 [3.74] ng/mL). Infants with gram-negative sepsis had higher sE-selectin levels than did those with gram-positive sepsis (P = .04). C-reactive protein was the best laboratory test for diagnosis of neonatal sepsis, with an overall sensitivity and specificity of 86% and 97%, respectively. Performing sE-selectin with C-reactive protein or immature to total ratio tests increased the specificity, but reduced the sensitivity, of the tests for the determination of neonatal sepsis. Plasma sE-selectin levels were higher in nonsurvivors than in survivors (P = .01) and were higher in those with hemodynamic dysfunction than in those without hemodynamic dysfunction (P < .001).

CONCLUSIONS

We conclude that plasma sE-selectin levels are elevated in neonatal sepsis. Significant elevation was associated with gram-negative sepsis. Plasma sE-selectin had low diagnostic value when used alone or in combination with other tests; however, it can be used as a prognostic indicator for the outcome of neonatal sepsis.

Epidemiology of neonatal sepsis in South Korea

BACKGROUND

Neonatal sepsis is a severe clinical syndrome characterized by systemic signs of infection, shock and system organ failure; diagnosis is confirmed on positive culture from a normally sterile site(s). There are few reports comparing incidence, mortality, and risk factors between clinically diagnosed sepsis and that confirmed by culture.

METHODS

All infants diagnosed with early- (within first 72 h after birth) or late-onset (72 h-4 weeks after birth) neonatal sepsis between 1997 and 1999 from four neonatal centers in South Korea, were investigated.

RESULTS

The estimated incidence rate of neonatal sepsis during the 3 years was 30.5 per 1000 live births for clinical sepsis and 6.1 per 1000 live births for sepsis with positive culture, with case-fatality rates of 4.7% and 2.2%, respectively. When only early-onset sepsis was considered, the incidence and fatality rates were 25.1 per 1000 live births and 6.1% for clinical sepsis, and 4.3 per 1000 live births and 2.5% for culture-confirmed sepsis, respectively. For the 179 patients (185 causative organisms) of proven sepsis, Staphylococcus spp. including S. aureus were the most frequent isolates. In early-onset clinical sepsis, having very low birthweight (<or=1500 g), a low Apgar score at 5 min (<or=7), and being male were related to higher rates of case-fatality (relative risk: 11.3, 6.8 and 2.5, respectively).

CONCLUSIONS

Clinical sepsis was more common than culture-confirmed sepsis and had a higher case-fatality rate. It seems prudent to take rapid and decisive steps toward better management of the high-risk group whether the sepsis is clinically diagnosed or culture confirmed.

Risk factors for neonatal infections in full-term babies in South Korea

PURPOSE

Since 1997, private postnatal care facilities (San-hu-jo-ri-won in Korean) have emerged to take the role of the family. As a result, neonates are now exposed to many people and are very vulnerable to infection. However, there has been no study on the influence of postnatal care facilities on neonatal infection. The aim of this study was to determine the risk factors of neonatal infection in full-term babies in Korea.

MATERIALS AND METHODS

We followed up 556 pregnant women and their babies for 4 weeks after their births at 2 hospitals in Seoul and Daejeon from October 2004 to September 2005. Among 512 full-term babies, 58 had infectious diseases. To determine the risk factors for infection, 53 infected neonates at 4-28 days of life and 413 healthy neonates were compared.

RESULTS

The incidence of neonatal infection at 4 to 28 days after birth was 10.5%. After adjusting the related factors, the number of siblings (OR = 2.05, 95% CI = 1.13-3.71 for 1 or more) and postnatal care facilities or home aides (OR = 1.91, 95% CI = 1.07-3.45) were significant risk factors. Formula or mixed feeding (OR = 1.66, 95% CI = 0.91-3.04) increased the risk of neonatal infection but it was not statistically significant.

CONCLUSION

When the newborns had siblings, stayed at postnatal care facilities, or were cared for by home aides, the risk of neonatal infections significantly increased. Further research on the feeding effect on neonatal infection and evaluation of prevention efforts are needed.

Low mannose-binding lectin (MBL) levels in neonates with pneumonia and sepsis

We investigated whether deficiency of mannose-binding lectin (MBL), a component of innate immunity, is associated with neonatal pneumonia and sepsis during the first 72 h, i.e. early onset, and during the first month after birth. In 88 neonatal intensive care patients (71 premature), MBL2 genotype and MBL plasma levels at birth were determined prospectively by Taqman analysis and enzyme-linked immunosorbent assay, respectively. Thirty-five neonates (40%) had low, i.e. </= 0.7 microg/ml, MBL plasma levels at birth. Median (interquartile range) MBL plasma levels in 32 no early-onset sepsis (EOS) cases, 44 possible EOS cases and 11 EOS cases were 1.57 (0.57-2.67) microg/ml, 1.05 (0.41-1.70) microg/ml and 0.20 (0.10-0.77) microg/ml, respectively (P < 0.01). During the first month, 28 neonates (32%) had no infection, 49 (55%) had suspected infection, five (6%) had pneumonia and six (7%) had culture-proven sepsis. Low MBL levels at birth were associated both with an increased risk of developing pneumonia (OR: 12.0; 95% CI: 1.1-126.1; P = 0.04) and culture-proven sepsis (OR: 15.0; 95% CI: 1.5-151.3; P = 0.02). These results were confirmed by genetic analysis of MBL deficiency. Low MBL levels at birth are associated with an increased risk of early-onset sepsis, culture-proven sepsis and pneumonia during the first month of life.

Infectious disease morbidity among young HIV-1-exposed but uninfected infants in Latin American and Caribbean countries: the National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study

OBJECTIVE

The goal was to describe the frequency, characteristics, and correlates of infectious disease morbidity during the first 6 months of life among HIV-1-exposed but uninfected infants.

METHODS

The study population consisted of infants enrolled in the National Institute of Child Health and Human Development International Site Development Initiative Perinatal Study who were HIV-1 uninfected and had follow-up data through the 6-month study visit. Definitive and presumed infections were recorded at study visits (birth, 6-12 weeks, and 6 months).

RESULTS

Of 462 HIV-1-uninfected infants with 11,644 child-weeks of observation, 283 experienced > or = 1 infection. These 283 infants experienced 522 infections (1.8 infections per infant). The overall incidence rate of infections was 4.5 cases per 100 child-weeks of observation. Overall, the most common infections were skin or mucous membrane infections (1.9 cases per 100 child-weeks) and respiratory tract infections (1.7 cases per 100 child-weeks). Thirty-six percent of infants had > 1 respiratory tract infection (1.8 cases per 100 child-weeks). Incidence rates of upper and lower respiratory tract infections were similar (0.89 cases per 100 child-weeks and 0.9 cases per 100 child-weeks, respectively). Cutaneous and/or oral candidiasis occurred in 48 neonates (10.3%) and 92 older infants (19.3%). Early neonatal sepsis was diagnosed in 12 infants (26.0 cases per 1000 infants). Overall, 81 of 462 (17.5%) infants were hospitalized with an infection. Infants with lower respiratory tract infections were hospitalized frequently (40.7%). The occurrence of > or = 1 neonatal infection was associated with more-advanced maternal HIV-1 disease, tobacco use during pregnancy, infant anemia, and crowding. Lower maternal CD4+ cell counts, receipt of intrapartum antibiotic treatment, and country of residence were associated with postneonatal infections.

CONCLUSIONS

Close monitoring of HIV-1-exposed infants, especially those who are anemic at birth or whose mothers have more-advanced HIV-1 disease or who smoked during pregnancy, remains important.

[Incidence of nosocomial infections at a neonatal intensive care unit: a six-year surveillance study]

INTRODUCTION

Nosocomial infection is a frequent complication in neonatal intensive care units (NICUs) attending patients who require lengthy hospitalization and frequent invasive techniques.

PATIENTS AND METHODS

This study is part of a prospective surveillance program for nosocomial infection in Spain. All patients admitted to NICUs between June 1999 and March 2005 were observed. CDC criteria were used as the standard definition for nosocomial infection.

RESULTS

A total of 1236 neonates (58% male) were admitted during the surveillance period, involving 19,420 days in the NICU. The average birth weight was 1947.6 +/- 1009.5 g and average gestational age was 32.9 +/- 5.4 weeks. The most frequent associated pathology was respiratory distress (23.06%). A total of 316 nosocomial infections were diagnosed in 226 neonates, 76.7% affecting premature neonates (< 1500 g). The most frequent location was bacteremia (56.3%), and there was a predominance of coagulase-negative staphylococci (46.05%). Gram-negative microorganisms were isolated in 32.1% of the cases (Escherichia coli and Pseudomonas aeruginosa were the most frequent pathogens). Overall incidence of nosocomial infection was 25.6%. Overall mortality was 6.6%, with higher mortality in the group with nosocomial infections (8.7%).

CONCLUSIONS

Nosocomial infection rates are acceptable, with a typical epidemiological pattern for these units. Presence of a central catheter increased the risk. A program to promote proper hand washing should be considered. We do not recommend a continuing surveillance strategy in these units.

Surveillance for nosocomial infections in veterinary hospitals

Surveillance for nosocomial infection and disease is a critical component in an integrated and highly effective infection control program. Surveillance activities provide a sensory role to guide ongoing control practices so that they are focused and efficient. Without input from surveillance results, infection control practices are likely to be guided more by emotion and opinion than by data and evidence. This article discusses issues to be considered when developing effective nosocomial infection surveillance programs as well as the historical perspective of surveillance efforts for nosocomial infection in human health care settings.

Reduced risk of neonatal respiratory infections among breastfed girls but not boys

OBJECTIVE

The effect of breastfeeding on community-acquired neonatal infections has not been well studied, although the neonatal period is one of special vulnerability to infectious pathogens. Respiratory tract infections are the neonatal infection most commonly diagnosed after nursery discharge. We therefore chose respiratory tract infections diagnosed after nursery discharge as representative of neonatal community-acquired infection and studied the impact of breastfeeding on this neonatal infection syndrome.

METHODS

An unmatched nested case-control study was performed within a previously defined study cohort of 13 224 mother-infant pairs delivering between October 1, 1990, and March 31, 1998. Infants who were delivered at < 37 weeks' gestation were excluded. Neonatal respiratory tract infections were defined using modified National Nosocomial Infections Surveillance System criteria and were included in the case series when diagnosed after nursery discharge and at age < or =30 days. Infant feeding status during the first month of life was ascertained using automated text search of electronic medical records and was categorized as exclusive breastfeeding, mixed feeding, or exclusive formula feeding.

RESULTS

A total of 241 neonatal respiratory tract infections were found, and 1205 control subjects were selected. Compared with control subjects, case infants were more often born during the winter respiratory syncytial virus season (48% vs 33%), more likely to have a sibling present (70% vs 54%), and more likely to be a member of a socioeconomically at-risk family (24% vs 18%). Case patients were less likely to be exclusively breastfed (38% vs 44%) and equally likely to be exposed to mixed feeding (35% vs 34%) relative to control subjects. When compared with formula feeding only, the odds ratio (OR) of exclusive breastfeeding was 0.70 (95% confidence interval [CI]: 0.49-0.99) and that of mixed feeding was 0.83 (95% CI: 0.58-1.2). However, when stratified by infant sex, the inverse association between breastfeeding and risk of neonatal respiratory tract infection was confined to neonatal girls, for whom the unadjusted ORs associated with breastfeeding only and mixed feeding were 0.5 (95% CI: 0.29-0.78) and 0.6 (95% CI: 0.35-0.93), respectively. There was no meaningful association between breastfeeding and risk of neonatal respiratory tract infection among neonatal boys, for whom the unadjusted ORs associated with breastfeeding only and mixed feeding were 1.1 (95% CI: 0.63-1.8) and 1.3 (95% CI: 0.74-2.1), respectively. After adjustment for year of birth, season of birth, siblings, and socioeconomic status, both exclusive breastfeeding and mixed feeding remained protective among girls, with ORs of 0.5 (0.29-0.78) and 0.6 (0.34-0.93), respectively. The corresponding ORs for boys were 1.1 (0.64-2.0) and 1.4 (0.78-2.4).

CONCLUSIONS

Breastfeeding was inversely associated with reduced risk of neonatal respiratory tract infections in girls but not in boys. Breastfeeding may confer protection against some community-acquired infections as early as the first month of life.

Intrapartum antibiotics and neonatal invasive infections caused by organisms other than group B streptococcus

OBJECTIVES/STUDY DESIGN

Administration of group B streptococcal (GBS) antibiotic prophylaxis to women in labor has dramatically reduced the incidence of GBS neonatal disease, but there is little information on its impact on neonatal infections caused by other organisms. We conducted a nested case-control study to define the association between maternal intrapartum antibiotics and risk of neonatal non-GBS infection.

RESULTS

In our study population, 114 of 13,224 infants had 115 non-GBS infections. The incidence of non-GBS neonatal infections fell during the study period, ranging from an attack rate of 9.6 per 1000 infants in 1990 to 1992 to 8.0 per 1000 infants in 1996 to 1998, although this trend was not statistically significant (P >.05). The unadjusted association between neonatal infection and GBS prophylaxis was 0.89 (95% CI, 0.29, 2.6) and between neonatal infection and maternal intrapartum antibiotic due to any cause was 1.3 (95% CI, 0.65, 2.8).

CONCLUSIONS

The current policy of GBS maternal prophylaxis does not appear to convey excess risk of non-GBS infection to neonates.