Early-onset Neonatal Infection Research Articles

Prevalence of oropharyngeal group B Streptococcus colonization in mothers, family, and health care providers.

ObjectiveTo determine the prevalence and serotype of oropharyngeal Group B Streptococcal (GBS) colonization of mothers, their family & friends, and health care providers of recently delivered patients as a potential reservoir of neonatal exposure to GBS.MethodsThis is a prospective, single-center observational study of: (1) patients, (2) their family and friends, and (3) health care providers all of whom may come in close contact with neonates. Oropharyngeal GBS colonization and serotype was determined.ResultsThree hundred and seventy three samples were collected. The prevalence of oropharyngeal GBS colonization among all study participants was 23.1% (N = 86). The most commonly found serotypes were 1b (12.8%, N = 11), III (27.9%, N = 24), and V (17.4%, N = 15). The prevalence of oropharyngeal GBS colonization among mothers was 26% (N = 31/121), 22% (N = 39/178) in family and friends, and 21.6% (N = 16/74) in health care providers.ConclusionGroup B Streptococcus colonizes the oropharynx in 1 in 5 mothers, family and friends, and health care providers who come in direct contact with neonates. Further research is needed to determine if this potential reservoir for neonatal exposure could lead to early or late onset neonatal GBS colonization or infection.

Early-onset neonatal infection in pregnancies with prelabor rupture of membranes in Kosovo: A major challenge

Objective:Prelabor rupture of membranes (PROM) is a common event in obstetrics that has a major impact in pregnancy outcome. This condition is linked to a number of pregnancy and birth complications with early-onset neonatal infection (EONI) being one of the major threats. This study was undertaken to determine the rate of neonatal infection in newborn infants with a maternal history of PROM and to evaluate the association of risk factors with neonatal infection following PROM.Materials and Methods:A cross-sectional descriptive design was used to analyze a population of 200 pregnant women presenting to the Obstetrics and Gynecology Tertiary Center in Kosovo (between 2013 and 2015) with PROM who gave birth to single newborns. Data including demographic characteristics, neonatal outcome, and risk factors for infectious neonatal morbidity were recorded and analyzed.Results:The study included 200 pregnant women with PROM and their newborns. Participant demographics included: the majority were young, aged between 20 and 29 years (67%), primiparous (67.5%), unemployed (92%), completed secondary level of education (83%), and with middle socioeconomic status (86%). Overall, 13% of the newborns had early-onset neonatal infection, and sepsis was proven in 5% of cases. Newborns of mothers with risk factors such as preterm (<37 weeks) PROM, low gestational weight at birth, prolonged rupture of membranes, maternal colonization, and low Appearance, Pulse, Grimace, Activity, Respiration score at birth had higher rates of infection compared with newborns of mothers without these risk factors.Conclusion:The rate of EONI in pregnancies complicated with PROM continues to be a global challenge in perinatology, and as this study reports, also a major challenge for Kosovo. Future research, revision and improvement on prenatal care and practices, timing of delivery, medical treatment, and prophylactic use of antibiotics in PROM are needed to reduce rates.

Neonatal early-onset blood stream infection caused by group B Streptococcus: analysis of 55 cases

Objective To investigate the clinical characteristics, prenatal risk factors and antibiotic resistance of neonatal early-onset blood stream infection caused by group B Streptococcus (GBS) and to provide evidence for the management of GBS infection. Methods From January 1, 2001 to May 31, 2017, 55 neonates diagnosed with GBS-associated early-onset blood stream infection in the International Peace Maternity & Child Health Hospital were enrolled. They were divided into two groups: GBS early-onset sepsis (GBS EOS) group (n=40) and bacteremia group (n=15). Clinical data were retrospectively analyzed and compared between the two groups with two independent-samples t test and Chi-square test. Results The incidence of neonatal GBS-associated early-onset blood stream infection was 0.31‰(55/179 738). Those neonates with bacteremia had no clinical manifestations. However, in the GBS EOS group, the main manifestations were respiratory abnormalities [respiratory distress (35%, 14/40) and apnea (10%, 4/40)], jaundice (40%, 16/40) and poor perfusion [low blood pressure, etc. 32%(13/40)], and the main abnormal results of blood routine test were increased C-reaction protein [>10 mg/L, 100% (40/40)] and elevated white blood cell count [>25×109/L, 78% (31/40)]. Compared with GBS EOS group, bacteremia group had a lower rate of vaginal delivery [1/15 vs 52% (21/40), χ2=9.549, P=0.002] and higher rates of maternal fever [15/15 vs 55% (22/40), χ2=10.034, P=0.002], chorioamnionitis [15/15 vs 68% (27/40), χ2=6.384, P=0.012] and empirical administration of antibiotics to infants [15/15 vs 70% (28/40), χ2=5.759, P=0.016]. All tested GBS strains were susceptible to penicillin, ampicillin and vancomycin, but resistant to clindamycin (42%, 22/53) and erythromycin (46%, 24/52). Conclusions GBS is one of the predominant pathogens causing neonatal early-onset blood stream infection. Respiratory distress, apnea, jaundice and poor perfusion are the main manifestations. Penicillin and ampicillin are the treatment choice for neonatal early-onset GBS infection. Active and appropriate intrapartum management of pregnancies with high risk of intrauterine GBS infection as well as prophylactic prescription of antibiotics to infants may help to prevent or alleviate the symptoms of neonatal early-onset blood stream infection. Key words: Bacteremia; Streptococcus agalactiae; Streptococcal infections; Microbial sensitivity tests; Infant, newborn

Early-onset neonatal infections in Australia and New Zealand, 2002–2012

BackgroundThe epidemiology of early-onset neonatal sepsis (EONS) varies over time, and requires regular surveillance.ObjectiveTo analyse data on EONS in Australia and New Zealand.MethodsRetrospective analysis of data collected longitudinally from multiple...

Revisiting the Diagnostic Criteria of Clinical Chorioamnionitis in Preterm Birth

(BJOG. 2017;124(5):775–783) Although maternal fever has long been considered a distinguishing feature in the clinical diagnosis of chorioamnionitis, studies have indicated that maternal fever does not have high sensitivity in the prediction of neonatal infectious morbidities, such as early-onset neonatal sepsis (EONS). Because undiagnosed clinical chorioamnionitis can cause serious adverse neonatal outcomes, including neonatal sepsis and perinatal death, it is crucial to be able to predict early-onset neonatal infection as accurately as possible. Several recent studies have attempted to determine sensitive markers of infection. However, there has been little research on the differential effects of fever as a criterion for the diagnosis of clinical chorioamnionitis in women with preterm prelabor rupture of membranes (PPROM) or preterm labor (PTL), a subgroup of patients who have typically received antibiotics as part of their usual management.

C-reactive protein and white blood cell count as predictors of maternal and neonatal infections in prelabour rupture of membranes between 34 and 41 weeks of gestation

Prelabour rupture of the membranes (PLROM) is defined as rupture of membranes before the onset of labour. It is one of the most common clinical events, where pregnancy can turn into a high-risk situation for mother and foetus. As prevention of PLROM is difficult, one has to concentrate on management to reduce its complications. Accurate prediction of infection remains a main challenge in cases of PLROM. We conducted a prospective study of all women admitted for PLROM at or after 34–41 weeks of gestation to investigate the predictive value of C-reactive protein (CRP) and white blood cell (WBC) count for early-onset neonatal infection (EONI) and maternal chorioamnionitis. The analysis was done by comparing areas under ROC curves and sensitivity. Lowest best cut off of maternal serum CRP level >4.9 mg/l and lowest cut off of WBC count 12,450/cumm have good predictive values for maternal chorioamnionitis and EONI.Impact statementWhat is already known on this subject? The ability to detect chorioamnionitis and predict neonatal infection at an early stage would be helpful in its treatment and would make it possible to prolong the pregnancy.What do the results of this study add? Maternal serum CRP level and WBC count obtained at admission are predictors of chorioamnionitis and EONI although WBC count alone is not a good indicator of them. A lowest best cut off of serum CRP level >4.9 mg/l and lowest cut off of WBC count 12,450/cumm have good predictive values for maternal chorioamnionitis and EON.What are the implications of these findings for clinical practice and/or further research? We propose that maternal serum CRP level and WBC count should be used as screening test for EONI and chorioamnionitis rather than a diagnostic test.

Protective effect of Group B Streptococcus type-III polysaccharide conjugates against maternal colonization, ascending infection and neonatal transmission in rodent models

Group B Streptococcus (GBS) is a normal inhabitant of recto-vaginal mucosae in up to 30% of healthy women. Colonization is a major risk factor for perinatal infection which can lead to severe complications such as stillbirth and neonatal invasive disease. Intra-partum antibiotic prophylaxis in colonized women is a safe and cost-effective preventive measure against early-onset disease in the first days of life, but has no effect on late-onset manifestations or on early maternal infection. Maternal immunization with capsular polysaccharide-based vaccines shows promise for the prevention of both early-onset and late-onset neonatal infections, although ability to prevent maternal colonization and ascending infection has been less studied. Here we investigated the effect of a GBS glycoconjugate vaccine since the very early stage of maternal GBS acquisition to neonatal outcome by rodent models of vaginal colonization and ascending infection. Immunization of female mice and rats with a type III glycoconjugate reduced vaginal colonization, infection of chorioamniotic/ placental membranes and bacterial transmission to fetuses and pups. Type III specific antibodies were detected in the blood and vagina of vaccinated mothers and their offspring. The obtained data support a potential preventive effect of GBS glycoconjugate vaccines during the different stages of pregnancy.

Barriers to implementing the NICE guidelines for early-onset neonatal infection: cross-sectional survey of neonatal blood culture reporting by laboratories in the UK

The National Institute for Health and Care Excellence published guidelines for managing early-onset neonatal infections in 2012. It recommended provision for reporting blood cultures (BCs) with growth detected or not detected at 36 h. To determine if this was followed, a telephone survey was conducted amongst lead biomedical scientists based at microbiology laboratories (N=209) in the UK. Overall, 202/209 responded and 139/202 had on-site facilities for BCs. BC results with growth detected or not detected at 36 h were available out-of-hours in 36/139 (26.6%) and 66/139 (47.5%) neonatal units, respectively. Early discontinuation of antibiotics should lead to improved antibiotic stewardship.

Antibiothérapie des infections néonatales bactériennes précoces chez les nouveau-nés nés à partir de 34 semaines d’aménorrhée

All newborns superior to 34 weeks of gestationnal age (GA) are concerned by these guidelines of the French Society of Neonatology and the French Society of Pediatrics. Only newborns at risk of Early-Onset Neonatal Bacterial Infection who are clinically symptomatic have to be treated with probabilistic antibiotherapy treatment. The antibiotic combination of choice is amoxicillin + gentamicin. The two exceptions that justify dual therapy with Cefotaxime and Gentamicin are the bacteriological documentation of Escherichia coli and/or the presence of clinical signs of severity. The continuation or not of the antibiotic treatment relies on the reevaluation of the clinical examination, the bacteriological culture results (blood culture and eventual Cerebro-Spinal-Fluid (CSF) culture) after 36-48 hours of treatment. Antibiotic treatment is continued for 7 days in case of positive blood culture, with amoxicillin alone if then bacterial species implicated are group B Streptococcus (GBS) or Listeria monocytogenes, with Cefotaxime alone in case of E.coli even if the strains are susceptible to aminopenicillins. In case of meningitis due to GBS or L. monocytogenes antibiotherapy is continued for 14 days with amoxicillin alone and 21 days of cefotaxime alone in case of E. coli meningitis. Specialist advice should be sought for other bacteria or extended-spectrum beat-lactamase-producing E. coli. and the absence of bacteriological documentation, according to the clinical evolution and the inflammatory parameters, it can be decided to continue or not the antibiotherapy.

Intrapartum group B Streptococcus screening in the labor ward by Xpert® GBS real-time PCR.

Group B Streptococcus (GBS) is the leading cause of neonatal infections in industrialized countries. Intrapartum antibiotic prophylaxis (IAP) given to colonized parturients is a key step for the prevention of neonatal early-onset infection. We compared the performances of Xpert® GBS polymerase chain reaction (PCR) (Cepheid, Sunnyvale, CA, USA) as a point-of-care system in labor wards to standard culture for intrapartum GBS detection. Pregnant women with a GBS-positive antenatal screening were prospectively included. A vaginal double swab was collected at the time of delivery for point-of-care Xpert® GBS PCR and GBS culture. A total of 565 pregnant women were included. Valid Xpert® GBS results were obtained for 488 (86.4%) women on the first attempt. Repeat testing improved the PCR success to 516 (91.3%) women. Among the 305 women positive for GBS by culture at delivery, only 238 (78.0%) were positive by Xpert® GBS PCR, cycle thresholds being correlated to culture quantification. Among 260 women negative for GBS culture, 56 (21.5%) were positive by Xpert® GBS PCR, including 50 where IAP was initiated before vaginal sampling. Overall, among the 565 women with GBS antenatal positive culture, only 335 (59.3%) were still positive at delivery whatever the technique used, resulting in unnecessary IAP for 40% of them. This large cohort study comparing intrapartum to antepartum GBS detection provides evidence that (i) Xpert® GBS PCR might be a valuable solution for intrapartum GBS detection compared to culture-based strategies and (ii) laboratory training of non-specialized staff is mandatory to reach the performances required for point-of-care tests.

Effect of neonatal respiratory distress syndrome on the value of serum procalcitonin to diagnose early-onset neonatal infection

目的 研究新生儿呼吸窘迫综合征(neonatal respiratory distress syndrome，NRDS)对早产儿生后早期血清降钙素原(procalcitonin，PCT)表达水平及诊断价值的影响。 方法 对大连医科大学附属大连市妇幼保健院新生儿科收治的199例早产儿进行回顾性研究，根据临床表现和实验室结果分为早发感染组和无早发感染组，其中无早发感染组再分为无感染NRDS组和无感染无NRDS组，比较生后12～24 h外周血PCT浓度，并绘制受试者工作特征曲线(receiver operating characteristic curve ，ROC曲线)评价PCT作为感染标志物的诊断价值。 结果 早发感染组早产儿血清PCT浓度[10.99(5.93，19.79)μg/L]高于无感染组中NRDS组[7.16(3.46，17.36)μg/L]和无NRDS组[0.98(0.37，2.21)μg/L]，差别有统计学意义(P<0.05)。无感染NRDS组早产儿血清PCT浓度高于无感染无NRDS组，差别有统计学意义(P<0.05)。依据早发感染组和无早发感染组血清PCT浓度绘制的ROC曲线下面积为0.800(95%可信区间为0.737～0.864)；依据早发感染组和无感染NRDS组血清PCT浓度绘制的ROC曲线下面积为0.607(95%可信区间为0.504～0.710)；依据早发感染组和无感染无NRDS组血清PCT浓度绘制的ROC曲线下面积为0.927(95%可信区间为0.883～0.971)。 结论 NRDS使早产儿生后12～24 h血清PCT浓度显著升高并降低了PCT预测感染的诊断价值。在无NRDS的早产儿中PCT仍然具有较高的诊断价值。

Serotype distribution and clinical correlation of Streptococcus agalactiae causing invasive disease in infants and children in Taiwan.

Streptococcus agalactiae, or group B Streptococcus (GBS), remains to be one of the leading pathogens causing invasive infections in infants. The clinical GBS isolates from sterile sites of patients younger than 18 years old were collected from October 1998 to December 2014 in two hospitals in Taiwan. Medical records were retrospectively reviewed. Every isolate was serotyped with a multiplex PCR assay. Multilocus sequence typing (MLST) was performed in representative isolates of different serotypes. A total of 205 GBS isolates were collected from 181 patients with 182 infection episodes. Serotype Ia was the most common in patients less than 72h old, whereas III the most common in patients older than 72h. In early-onset disease (0-6 days), Ia and III each caused 27.5% of the infection, followed by Ib (14.5%). In late-onset disease (7-89 days), serotype III predominated (75.3%), followed by Ia (10.1%) and Ib (6.8%). Thirty-one episodes (17%) were complicated with culture-confirmed meningitis. We compared serotype Ia and III patients, and found that serotype Ia patients were significantly younger (median age, 3 days), had more perinatal maternal fever and higher mortality. ST17 and ST19 were exclusively found in serotype III, while ST23 and ST24 comprised of 85% of serotype Ia. In Taiwan, serotypes Ia and III are the most common cause for early-onset and late-onset neonatal GBS infections, respectively. Some differences in the clinical features of invasive GBS infections caused by serotype Ia and III were observed.

Intrapartum PCR assay versus antepartum culture for assessment of vaginal carriage of group B streptococci in a Danish cohort at birth.

The aim of this study was to compare the performances of two strategies for predicting intrapartum vaginal carriage of group B streptococci (GBS). One strategy was based on an antepartum culture and the other on an intrapartum polymerase chain reaction (PCR). We conducted a prospective observational study enrolling 902 pregnant women offered GBS screening before delivery by two strategies. The Culture-strategy was based on vaginal and rectal cultures at 35–37 weeks’ gestation, whereas the PCR-strategy was based on PCR assay on intrapartum vaginal swab samples. An intrapartum vaginal culture for GBS was used as the reference standard from which the performances of the 2 strategies were evaluated. The reference standard showed a GBS-prevalence of 12%. The culture-strategy performed with a sensitivity of 82%, specificity of 91%, positive predictive value (PPV) of 55%, negative predictive value (NPV) of 98%, and Likelihood ratio (LH+) of 9.2. The PCR-strategy showed corresponding values as sensitivity of 83%, specificity of 97%, PPV of 78%, NPV of 98%, and LH+ of 27.5. We conclude that in a Danish population with a low rate of early-onset neonatal infection with GBS, the intrapartum PCR assay performs better than the antepartum culture for identification of GBS vaginal carriers during labor.

Group B streptococcal bacteriuria during pregnancy as a risk factor for maternal intrapartum colonization: a prospective cohort study.

Current evidence is inconclusive regarding the intrapartum administration of chemoprophylaxis, merely based on the presence of group B streptococcal (GBS) bacteriuria of any colony count, in the prevention of early-onset neonatal GBS infection. The aim of this study was to assess whether GBS bacteriuria is a risk factor for intrapartum colonization (IPC) regardless of urinary concentration or the results of late third-trimester rectovaginal screening cultures (RVSCs). Six hundred and eight pregnant women, with urine specimens cultured between May 2011 and May 2013, were enrolled in this prospective cohort study. RVSCs were available for 582 women and intrapartum rectovaginal cultures for 246. The prevalence of GBS bacteriuria and positive RVSCs was 10.8 and 16.5 %, respectively. The frequency of IPC was 15.9 % (39/246). Sensitivity, specificity, positive and negative predictive values of urine culture and of RVSC in predicting GBS IPC were 41, 94.7, 59.3 and 89.5 %, and 76.9, 95.4, 76.9 and 95.4 %, respectively. GBS bacteriuria was significantly associated with IPC, overall [relative risk (RR) 5.6] and in women with negative RVSC (RR 8.5), with bacteriuria <104 c.f.u. ml-1 (RR 5.9) or when both circumstances coexisted (RR 8.9). The urinary colony count was <104 c.f.u. ml-1 in 13 of the 16 women with GBS bacteriuria and IPC. GBS bacteriuria is a risk factor for IPC, irrespective of urinary GBS concentration or of colonization status at late gestation. Therefore, microbiology laboratories should search, and report, GBS of any colony count in urine from pregnant women, and not only in the presence of ≥104 c.f.u. ml-1 as the 2010 CDC guidelines recommend.

Group B Streptococcus detection in pregnant women via culture and PCR methods.

Group B Streptococcus (GBS), a source of neonatal infection, colonizes the gastrointestinal and genitourinary tracts of pregnant women. Routine screening for maternal GBS in late pregnancy and consequent intrapartum antibiotic prophylaxis have reduced the incidence of early-onset GBS neonatal infection. The aim of this study was to evaluate the performance of PCR, compared to culture (gold standard), in GBS colonization screening of pregnant women, and to establish the prevalence of GBS colonization among this population. Vaginal introitus and perianal samples were collected from 204 pregnant women, between the 35th and 37th weeks of pregnancy, at the Obstetrics and Gynecology Unit of the University of Caxias do Sul General Hospital between June 2008 and September 2009. All samples were cultured after enrichment in a selective medium and then assayed by culture and PCR methods. The culture and PCR methods yielded detection rates of vaginal/perianal GBS colonization of 22.5% and 26%, respectively (sensitivity 100%; specificity 95.6%; positive and negative predictive values 86.8% and 100%, respectively). A higher prevalence of GBS colonization was detected in the combined vaginal and perianal samples by both culture and PCR assay analyses. PCR is a faster and more efficient method for GBS screening, allowing for optimal identification of women who should receive intrapartum antibiotic prophylaxis to prevent newborn infection.

Wpływ wczesnych zakażeń na stężenie adiponektyny i leptyny w surowicy noworodków donoszonych

ObjectiveAdiponectin and leptin play an important role in the children development, but the effect of early-onset neonatal infections on their values is not well known. AimThe evaluation of serum adiponectin and leptin concentrations in healthy and infected full-term newborns, according to their gender, type of delivery, birth asphyxia and kind of infection and determination of correlations between concentrations of these two hormones and anthropometric parameters. Material and methodsThe study involved 166 newborns (95 boys, 71 girls), among them 85 infected and 81 healthy. Hormone concentrations were measured between 3rd and 7th day of life by ELISA method. ResultsSeptic newborns have significantly higher adiponectin concentration than healthy, and septic and local infected babies have higher leptin value than healthy, independently of their gender, anthropometric parameters, birth asphyxia and type of delivery. In healthy newborns negative correlation between adiponectin value and chest circumference, and between leptin concentration and body length was noted. Healthy female newborns have significantly higher leptin values than boys; healthy newborns born by elective cesarean section have higher adiponectin concentration than born spontaneously. Positive correlation between adiponectin and leptin concentrations in infected newborns was stated. Conclusions1. Early-onset infections in full-term eutrophic newborns contribute to increase of adiponectin and leptin concentrations, independently of their gender, birth asphyxia and type of delivery. 2. In infected newborns any significant correlations between adiponectin concentrations and birth weight, body length, chest and head circumferences were noted.

Procalcitonin in the diagnosis of early-onset neonatal infection in resource-limited settings

AbstractObjectives: To study the usefulness of procalcitonin (PCT) in comparison to C-reactive protein (CRP) in diagnosis of early onset neonatal infection (EONI) in resource-limited setting. Methods: Admitted newborns to two big neonatal units in Khartoum were investigated for EONI including CBC, urine analysis, blood culture, CRP and PCT. They were given Ampicillin and Gentamycin which were changed as per blood C/S results or according to clinical progress. CRP and PCT were done initially. PCT was repeated 8 h and CRP 36 h later. Decision to continue antibiotics was taken after getting results of 2nd CRP. Three categories were identified: Confirmed EONI were those with positive blood culture, non-infected were asymptomatic with negative blood culture/ other lab support; and the 3rd were those with negative blood culture but non-conclusive clinical/lab results. The 1st and 3rd categories were continued on antibiotics for 7–14 days. PCT levels were compared to CRP levels in the three categories. Results: ...

The application of heparin-binding protein in the diagnosis of early onset neonatal bacterial infection in newborns

The application of heparin-binding protein in the diagnosis of early onset neonatal bacterial infection in newborns

Flow cytometric white blood differential using CytoDiff™ in the diagnosis of neonatal early-onset infection

Objective: Neonatal early-onset infection is a life-threatening disease, requiring early diagnosis and treatment. Newborns at risk are identified by a combination of risk factors, clinical signs of infection and laboratory parameters such as white blood cell count and C-reactive protein (CRP). This method is labor-intensive, time consuming and has a variable reproducibility. New reliable diagnostic markers are needed to identify neonatal infection. This study presents additional leukocyte differential parameters produced by the automated flow cytometry and processing software using CytoDiff™ reagent (Beckman Coulter) in newborns suspected for early-onset infection.Methods: An analytic prospective observational case–control study was performed in which 185 newborns were included and retrospectively allocated into two groups, “infection likely” and “infection unlikely”. Leukocyte parameters of the CytoDiff™ technique were compared with microscopic slide differentiation and routine tests.Results: We showed significant lower numbers of monocytes, CD16(−) monocytes and lymphocytes (including T+/NK-lymphocytes) in neonates suspected for early-onset infection using CytoDiff™ technique. The manual counting did not demonstrate changes with respect to the number of monocytes in these neonates.Conclusions: The automated routine CytoDiff™ leukocyte differential provides an interesting additional diagnostic tool, next to routine laboratory diagnostics, in the diagnosis of neonatal early-onset infection.

Chorioamnionitis and early-onset neonatal infection.

Chorioamnionitis is associated with early-onset neonatal infection, but only a small fraction of women with chorioamnionitis has an infected infant. US guidelines recommend empiric antibiotics for well-appearing infants of mothers with chorioamnionitis. A 4-year US study of early-onset neonatal infection (defined as positive blood or CSF culture ≤72 h) collected data about clinical or histopathological maternal chorioamnionitis. An analysis aimed to determine how many chorioamnionitis-exposed infected infants were asymptomatic at birth.1 The incidence of early-onset infection was 1.02 per 1000 live births (389 episodes in 396 586 births). The mothers of 60% of infected infants had a diagnosis of chorioamnionitis; 29 (13%) of 229 had no reported symptoms at 6 h, and 21 (9%) remained symptom free at 72 h. Asymptomatic infants were no more likely than symptomatic infants to have received intrapartum antibiotics. Most infected infants (65%) were born preterm, 91% of them at 22–33 weeks' gestation, itself a risk factor for infection likely to warrant starting antibiotics. The authors estimated that, if current guidelines were followed and depending on chorioamnionitis prevalence, 60 to 1400 newborns would receive antibiotics for each infected asymptomatic newborn. Some chorioamnionitis-exposed newborns with culture-confirmed early-onset neonatal infection are asymptomatic, but empiric treatment on the basis of chorioamnionitis also results in treating large numbers of asymptomatic infants.