Diagnosis of enterovirus infection in the first 2 months of life by real-time polymerase chain reaction.

During summer and fall, enterovirus infections are responsible for a considerable proportion of hospitalizations of young infants. We prospectively studied the incidence of enterovirus infections via real-time polymerase chain reaction (PCR) in blood, feces, and cerebrospinal fluid samples from infants

Development of resistance to aminoglycosides among coagulase-negative staphylococci and enterobacteriaceae in a neonatal intensive care unit.

A prospective study of the development of resistance to aminoglycosides among coagulase-negative staphylococci (CNS) and Enterobacteriaceae (ENT) was conducted for all patients admitted to a neonatal intensive care unit (NICU) from October 1985 to January 1990. A change in antibiotic regimen from gentamicin to amikacin occurred in January 1986, due to widespread gentamicin resistance among CNS, the most important cause of nosocomial infections in this NICU. From 657 patients, 884 faecal cultures, 1505 cultures from the respiratory tract and 152 blood cultures were included in the study. After its introduction, susceptibility to amikacin decreased rapidly in faecal and respiratory CNS isolates (from 62% to 28% and from 58% to 23% respectively). During the first half year, resistance to amikacin in faecal CNS isolates developed more rapidly among antibiotic-treated patients than among patients not treated with antibiotics. Susceptibility to amikacin in CNS blood isolates decreased more slowly, from 94% to 58% in 1987, while subsequently an increase in susceptibility was observed to about 80% in 1989. The same difference in development of resistance in faecal and respiratory CNS isolates compared to CNS blood isolates was noticed for gentamicin and tobramycin. In contrast, ENT remained highly (85-100%) susceptible to amikacin, gentamicin and tobramycin throughout the study period. It was concluded that four years after its introduction amikacin still appeared to be a valuable antibiotic in combination treatment of the vast majority of clinically important infections occurring in our NICU, since both Enterobacteriaceae and the majority of CNS blood isolates proved to be susceptible to this agent.(ABSTRACT TRUNCATED AT 250 WORDS)

Neonatal sinusoidal heart rate pattern; changes after atropine administration.

A sinusoidal heart rate pattern is reported in a 15-day-old neonate with a cyanotic congenital heart disease. The modification of this pattern after stimulus and administration of atropine is discussed.

[Central venous catheters in newborn infants. Work Group Parenteral Nutrition of the Perinatology Section of the Dutch Pediatric Society]. / Centraal-veneuze catheters bij pasgeborenen. Werkgroep Parenterale Voeding van de sectie Perinatologie van de Nederlandse Vereniging voor Kindergeneeskunde.

In this article guidelines regarding the use of indwelling central venous catheters are given. Indications, insertion techniques, possible complications and management are described. Furthermore a survey of the commercially available catheters in the Netherlands is made.

[Chylothorax in the neonatal period]. / Chylothorax in de neonatale periode.

The data of 11 infants with chylothorax in the neonatal period, seven with congenital chylothorax and 4 infants with iatrogenic chylothorax are reported. Chylothorax in the neonatal period may cause birth asphyxia and serious respiratory problems. Among the infants with congenital chylothorax diagnosis can be established before birth by ultrasound technique, followed by optimal resuscitation to prevent asphyxia. In most of the cases, conservative treatment with continuous drainage and total parenteral nutrition is sufficient.

Chylothorax in the neonatal period.

Chylothorax is defined as an effusion of lymph in the pleural cavity. In the neonate both congenital and traumatic (iatrogenic) forms exist. Birth asphyxia and respiratory insufficiency are major symptoms of congenital chylothorax, requiring resuscitation and artificial ventilation. Antenatal diagnosis by ultrasound allows early therapeutic intervention such as ventilatory support and drainage of chylous fluid immediately after birth. Traumatic chylothorax is mainly seen after intrathoracic surgery. Treatment primarily consists of continuous or intermittent drainage of chyle with replacement of fluid-, electrolyte-, and protein losses and parenteral nutrition. Introduction of oral feeding is considered only after a substantial period without chyle production in the pleural cavity and consists of a medium-chain triglyceride containing formula. In a minority of cases surgical intervention is necessary.

Prevalence of molecular types and mecA gene carriage of coagulase-negative Staphylococci in a neonatal intensive care unit: relation to nosocomial septicemia.

Molecular typing of isolates revealed that neonatal coagulase-negative staphylococcal (CONS) septicemia is most frequently caused by predominant, antibiotic-resistant CONS types, which are widely distributed among both neonates and staff of the neonatal unit, suggesting cross-contamination. Therefore, infection control measures may be valuable in the prevention of this common nosocomial septicemia.

Nitric oxide production during the early neonatal period in small-for-gestational-age infants.

UNLABELLED: In a study of endogenous nitric oxide production in growth-retarded, very preterm newborns (<32 wk GA), urinary NOx/creatinine ratio and plasma guanosine 3',5'-cyclic monophosphate levels were determined during the early neonatal period. Newborns were divided into three groups: appropriate-for-gestational-age (AGA, n = 19), moderately small-for-gestational-age (SGA, n = 13) and severely SGA (n = 6) infants. Severely SGA infants showed significant higher values of nitric oxide derivatives during the first 24 h of life compared with the other groups. CONCLUSION: An increased NO production is found in SGA infants during the first 24 h after birth. This may reflect an increased intrauterine nitric oxide production in the feto-placental circulation found in cases with intrauterine growth retardation,

Antibody responses and opsonic activity in sera of preterm neonates with coagulase-negative staphylococcal septicemia and the effect of the administration of fresh frozen plasma.

Coagulase-negative staphylococcal septicemia is the most prominent nosocomial infection in neonatal intensive care units. Immaturity of host defenses in premature neonates is assumed to constitute an important risk factor. Opsonophagocytosis is considered to be the key host defense system against staphylococci with IgG antibodies as a major opsonin. For this reason we have studied serum IgG antibody titers and opsonic activity to coagulase-negative staphylococci in 20 infants with septicemia and 40 matched control subjects. In addition, we assessed the effect of administration of fresh frozen plasma (FFP) on IgG antibody titer and serum opsonic activity in 12 patients with septicemia. IgG antibodies, quantified by ELISA and opsonic activity, determined by flow cytometry, were expressed as a percentage of the value of pooled normal human reference serum. Both patients and control subjects showed low IgG titers (median, 21%; range, 1-192%) and a low opsonic activity (median, 33%; range, 8-484%) at birth. During the first 2 postnatal wk IgG titers decreased significantly in septicemia patients (from a median of 30 to 17%, p = 0.025), but not in control subjects, whereas opsonic activity remained unchanged. The titer of IgG antibodies increased significantly in septicemia patients after FFP administration (from a median of 17 to 41%, p = 0.002), whereas the effect on opsonic activity was unpredictable, showing a moderate increase in 10 out of 12 infants, and in 2 patients even a substantial decrease (>50%), despite adequate opsonic activity in the corresponding FFP batches. Immunoblotting of sepsis isolates with the corresponding patient sera demonstrated that septicemic infants may generate IgG antibodies against their blood isolate. Neonates who acquire coagulase-negative staphylococcal septicemia cannot be distinguished from control subjects on the basis of IgG antibodies and opsonic activity to staphylococci either at birth or during the first 2 postnatal wk. The administration of FFP to septicemia neonates has an unpredictable effect on opsonic activity and therefore does not seem to be a useful addition to antibiotic therapy.

Clinical outcome of cephalothin versus vancomycin therapy in the treatment of coagulase-negative staphylococcal septicemia in neonates: relation to methicillin resistance and mec A gene carriage of blood isolates.

OBJECTIVE: Coagulase-negative staphylococci (CONS) are the most common causative agents in neonatal nosocomial septicemia. Because of widespread methicillin resistance among CONS, empiric therapy with vancomycin is recommended as the primary antibiotic regimen for these infections. In our unit, empiric treatment of nosocomially acquired septicemia consists of cephalothin and gentamicin, which are adjusted subsequently according to the determined bacterial susceptibility profile. Vancomycin is initiated only when the patient has been treated recently with cephalothin or when intravascular lines or endotracheal tube are colonized with oxacillin/cephalothin-resistant CONS strains. The aim of the present study was to evaluate the efficacy of our antibiotic regimen for CONS septicemia, in relation to methicillin-resistance and the carriage of mec A gene, encoding methicillin resistance, among CONS blood isolates from our unit. METHODS: Clinical symptoms of septicemia, clinical outcome, and laboratory parameters of septicemia (C-reactive protein) were studied retrospectively in 66 patients with CONS septicemia. The diagnosis of septicemia was made by the attending neonatologist and was defined by clinical symptoms of septicemia in the presence of a positive finding of a blood culture test, which was performed using a defined protocol. All CONS blood isolates were included to determine mec A gene carriage. RESULTS: In the 66 patients, three treatment categories were distinguished: treatment with cephalothin (25 patients, 38%); with vancomycin (15 patients, 23%); and primary treatment with cephalothin, switched subsequently to vancomycin (26 patients, 39%). It was found that 92% of all CONS blood isolates (61/66) were mec A-positive. Concordance of mec A gene carriage with methicillin/oxacillin resistance was found in 56 of 66 isolates (85%); 10 of 61 (16%) isolates that were mec A-positive were determined as oxacillin-susceptible. Although 22 of the 25 blood isolates of the cephalothin-treated patients were mec A-positive, clinical recovery was uneventful. In the 26 patients in whom antibiotic therapy was switched from cephalothin to vancomycin, two strains were cephalothin-susceptible and 8 patients already had recovered clinically before the switch, which was based solely on susceptibility test results. CONCLUSIONS: Cephalothin was found to be clinically efficacious in the treatment of neonatal CONS septicemia, despite a steadily increasing mec A gene carriage of CONS blood isolates in our neonatal intensive care unit and a corresponding high methicillin/oxacillin resistance. Hence, cephalothin remained the antibiotic of first choice in the treatment of CONS septicemia in our unit, with vancomycin selected exclusively for cases not responding to initial cephalothin treatment, or for patients developing CONS septicemia during or after recent cephalothin treatment. By applying this approach in our unit, we were able to reduce vancomycin use from 62% in 1994 to 1995 to 21% in 1997. This shows that such a policy may result in an important reduction of vancomycin use, which may aid in postponing the threatening emergence of vancomycin resistance among Gram-positive cocci.

Severe neonatal group A streptococcal disease.

UNLABELLED: Since the mid-1980s, an increase in incidence of invasive disease caused by group A streptococci has been noted amongst adults and children; however, neonatal disease is still rare. Between 1979 and 1998, seven neonates with severe group A streptococcal disease were admitted to our neonatal intensive care unit. The clinical presentation, treatment and outcome are described. In three cases of early-onset disease vertical transmission was documented. CONCLUSION: Because the incidence of group A streptococcal disease in the general population seems to have increased over the last two decades, we should be aware of the possibility and particularly the severity of group A streptococcal disease in the neonatal period.

Plasma guanosine 3',5'-cyclic monophosphate and severity of peri/intraventricular haemorrhage in the preterm newborn.

UNLABELLED: A poorly controlled cerebral circulation, caused by excessive production of nitric oxide, has been suggested as predisposing to peri/intraventricular haemorrhage (PIVH) in the immature neonate. It is hypothesized that a relation exists between plasma cyclic GMP (cGMP) as an effector of endogenous vasodilatory nitric oxide production and severity of PIVH. In 83 consecutively admitted preterm neonates, nitric oxide production was assessed by measuring plasma cGMP at 0, 24, 48, 72 and 168 h of age. Simultaneously, cranial ultrasound investigations were performed and haemodynamic parameters registered. The investigations showed that 60 neonates (72%) had no PIVH; 18 neonates (22%) had mild to moderate PIVH; and 5 neonates (6%) had severe PIVH. At 48 and 72 h of age, cGMP levels of infants with severe PIVH were significantly higher than those of infants with no or only mild PIVH, whereas at 72 and at 168 h, infants with moderate PIVHs had significantly higher cyclic cGMP levels than infants without PIVH. Finally, at 168 h of age infants with mild PIVH also had higher cyclic cGMP values than those of infants without PIVH. Maximal cGMP values preceded the final extension of PIVH in moderate and severe PIVHs. Blood pressure support was necessary significantly more often in infants with moderate and severe PIVH. A logistic regression model revealed that cGMP was significantly associated with PIVH, irrespective of gestational age, mean arterial pressure or severity of infant respiratory distress syndrome. CONCLUSION: Increased cGMP levels are associated with the development of PIVH. It is suggested that vasodilatory nitric oxide-induced impairment of cerebral autoregulation plays a role here.

Population pharmacokinetics of gentamicin in preterm neonates: evaluation of a once-daily dosage regimen.

Population pharmacokinetic parameters of gentamicin in preterm neonates on a once-daily dosage regimen of 3.0 mg/kg given intravenously every 24 hours were established prospectively. In 34 preterm neonates with a mean gestational age of 32 +/- 4 (SD), 182 serum gentamicin levels (91 peak/trough pairs) were determined. Individual adjustments of dose or dosage interval were calculated by computer-aided Bayesian forecasting. The parameters Vd, ke, and CL for each patient were obtained by the nonparametric estimation of maximization method. The predictive power of the model was calculated and the pharmacokinetic estimates were statistically analyzed with SPSS/PC. Cluster analysis showed a division into 2 subpopulations (designated 1 and 2) on the basis of postnatal age. The mean +/- SD postnatal age of subpopulation 1 (n = 29) was 6 +/- 2 days (range 1-7) and of subpopulation 2 (n = 5) 15 +/- 4 days (range 12-24). The mean +/- SD gentamicin relative clearances of subpopulation 1 and subpopulation 2 were 0.0515 +/- 0.0128 and 0.1026 +/- 0.0102 L kg(-1) hr(-1), respectively (p < 0.05). The mean +/- SD values for Vd (Lkg(-1)) in both populations 1 and 2 were 0.6916 +/- 0.1670 and 0.7509 +/- 0.1961, respectively (not significantly different). For ke these data were 0.0744 +/- 0.0200 and 0.1366 +/- 0.0522 (p < 0.05). Statistics showed that the data for Vd and ke of subpopulation 1 were normally distributed (Vd and ke skewness 1.61 and 1.46; kurtosis 3.09 and 3.10 respectively). The model yielded a bias of -0.11 mg/L and a precision of 0.36 mg/L. It is recommended that gentamicin be started in a dosage of 3.5 mg/kg intravenously once-daily under close monitoring.

Epidemiological survey of neonatal non-polio enterovirus infection in the Netherlands.

The epidemiological, virological, and clinical data of 119 infants less than 30 days of age with enteroviral infection collected from January 1993 to November 1995 by the diagnostic virology laboratories were analyzed retrospectively. Ninety-eight isolates (83%) were obtained in the period of May 1 to December 1 with a peak in the summer months. Sixty-five percent (n = 78) of neonates became ill within the first 2 weeks of life. Echoviruses and Coxsackie virus type B were isolated most frequently, in 77 (65%) and 29 (24%) infants, respectively. Diagnosis was made by viral isolation from stool, nasopharyngeal swab, cerebrospinal fluid, and blood. One hundred four (87%) infants developed fever and 25 (21%) infants had diarrhea. A clinical diagnosis of sepsis was made in 42 (35%) infants and meningitis was diagnosed in 28 (24%) cases. The great majority of sepsis cases (36/86%) occurred in infants less than 15 days of age. In conclusion, non-polio enteroviruses (especially echoviruses) are a common and underreported cause of neonatal infection in the Netherlands in the summer months and are associated with a clinical diagnosis of sepsis or meningitis cases in the first 2 weeks of life in a high proportion of cases.

Microbiological factors associated with neonatal necrotizing enterocolitis: protective effect of early antibiotic treatment.

AIM: The incidence of necrotizing enterocolitis (NEC) strongly increased in an neonatal intensive care unit (NICU) in 1997 and 1998 compared with previous years, which coincided with increased incidence of nosocomial sepsis. Specific risk factors related to this NICU and a possible relationship between NEC and nosocomial sepsis were studied retrospectively, including all patients with NEC since 1990 and matched controls. METHODS: Clinical and bacteriological data from the period before the development of NEC and a similar period for the controls were collected retrospectively and corrected for birthweight and gestational age. Statistical analysis was performed by a stepwise regression model. RESULTS: Data of 104 neonates with NEC and matched controls were analysed. The median day of onset of NEC was 12 d (range 1-63 d). Significant risk factors for NEC were: insertion of a peripheral artery catheter [odds ratio (OR) 2.3, 95% confidence interval (95% CI) 1.3-3.9] and a central venous catheter (OR 5.6, 95% CI 3.1-10.1), colonization with Klebsiella sp. (OR 3.4, 95% CI 1.5-7.5) and Escherichia coli (OR 2.1, 95% CI 1.0-4.5), and the occurrence of sepsis, in particular due to coagulase-negative staphylococci (OR 2.6, 95% CI 1.4-5.1). The risk for NEC was decreased after the early use (< 48 h after birth) of amoxicillin-clavulanate and gentamicin (OR 0.3, 95% CI 0.2-0.6). CONCLUSION: Insertion of central venous and peripheral arterial catheters is positively associated with NEC, as is colonization with the Gram-negative bacilli Klebsiella and E. coli and the occurrence of sepsis, particularly due to coagulase-negative staphylococci. Early treatment with amoxicillin-clavulanate and gentamicin is negatively associated with NEC and may be protective against NEC.