Coronavirus-related nosocomial viral respiratory infections in a neonatal and paediatric intensive care unit: a prospective study

The incidence of nosocomial viral respiratory infections (NVRI) in neonates and children hospitalized in paediatric and neonatal intensive care units (PNICU) is unknown. Human coronaviruses (HCoV) have been implicated in NVRI in hospitalized preterm neonates. The objectives of this study were to determine the incidence of HCoV-related NVRI in neonates and children hospitalized in a PNICU and the prevalence of viral respiratory tract infections in staff. All neonates (age< or =28 days) and children (age>28 days) hospitalized between November 1997 and April 1998 were included. Nasal samples were obtained by cytological brush at admission and weekly thereafter. Nasal samples were taken monthly from staff. Virological studies were performed, using indirect immunofluorescence, for HCoV strains 229E and OC43, respiratory syncytial virus (RSV), influenza virus types A and B, paramyxoviruses types 1, 2 and 3 and adenovirus. A total of 120 patients were enrolled (64 neonates and 56 children). Twenty-two samples from 20 patients were positive (incidence 16.7%). In neonates, seven positive samples, all for HCoV, were detected (incidence 11%). Risk factors for NVRI in neonates were: duration of hospitalization, antibiotic treatment and duration of parenteral nutrition (P<0.01). Monthly prevalence of viral infections in staff was between 0% and 10.5%, mainly with HCoV. In children, 15 samples were positive in 13 children at admission (seven RSV, five influenza and three adenovirus) but no NVRI were observed. In spite of a high rate of community-acquired infection in hospitalized children, the incidence of NVRI with common respiratory viruses appears low in neonates, HCoV being the most important pathogen of NRVI in neonates during this study period. Further research is needed to evaluate the long-term impact on pulmonary function.

Materno-fetal transmission of human coronaviruses: a prospective pilot study

This prospective pilot study investigates the possibility of materno-fetal transmission of human coronaviruses (HCoV) responsible for cases of neonatal infection. This vertical transmission was studied with 159 samples from mother-child couples: maternal vaginal (MV) and respiratory (MR) samples during labor; and newborn gastric sample (NG) with detection of HCoV (229E, OC-43, NL-63, HKU1) via real time RT PCR. HCoV was detected in 12 samples (229E: 11; HKU1: 1) from seven mother-child couples. For three couples, only MR tested positive (cases 1–3). For two other couples all three samples (MV, MR and NG) tested positive (cases 4 and 5). For case 6, only MV and NG tested positive. In case 7, only MV was positive. Possible vertical transmission of HCoV was hypothesized in this pilot study and requires further investigation on a larger scale.

[Nosocomial infections due to human coronaviruses in the newborn]

Human coronaviruses, with two known serogroups named 229-E and OC-43, are enveloped positive-stranded RNA viruses. The large RNA is surrounded by a nucleoprotein (protein N). The envelop contains 2 or 3 glycoproteins: spike protein (or protein S), matrix protein (or protein M) and a hemagglutinin (or protein HE). Their pathogen role remains unclear because their isolation is difficult. Reliable and rapid methods as immunofluorescence with monoclonal antibodies and reverse transcription-polymerase chain reaction allow new researches on epidemiology. Human coronaviruses can survive for as long as 6 days in suspension and 3 hours after drying on surfaces, suggesting that they could be a source of hospital-acquired infections. Two prospective studies conducted in a neonatal and paediatric intensive care unit demonstrated a significant association of coronavirus-positive nasopharyngal samples with respiratory illness in hospitalised preterm neonates. Positive samples from staff suggested either a patient-to-staff or a staff-to-patient transmission. No cross-infection were observed from community-acquired respiratory-syncitial virus or influenza-infected children to neonates. Universal precautions with hand washing and surface desinfection could be proposed to prevent coronavirus transmission.

[Pilot epidemiologic study of transmission of cytomegalovirus from mother to preterm infant by breastfeeding]

Transmission of cytomegalovirus (CMV) infection from mothers to preterm infants during breastfeeding may be symptomatic and long term consequences are unknown. This study evaluated the kinetics of CMV load in breastmilk and the rate of postnatal CMV transmission via breastmilk from mothers to their preterm infants.

METHODS

Prospective study of mother-child pairs after preterm delivery before 33 weeks. Exclusion of donor breast milk and of CMV-seropositive blood products. Material used was maternal CMV serostatus, ear swab of the infant at birth, weekly screened breast milk and children's urine by rapid viral culture.

RESULTS

During a 5-month period 28 mother-infant pairs with 34 preterm infants were studied. Eighteen women (64.3%) were CMV-seronegative at birth; breastmilk samples and the infants' urine remained CMV-negative. Eight of the 10 seropositive mothers, who had 11 preterm infants, excreted CMV into breast milk (80%). CMV excretion into breast milk was detected during the first week after delivery in 66% cases and was at its peaked between 3 to 5 weeks after delivery. Out of the 7 CMV-exposed infants, CMV transmission was confirmed in only one asymptomatic case. Total quantity of breast milk intake did not seem discriminative for CMV transmission.

CONCLUSION

In CMV-seropositive mothers of preterm infants a high incidence of CMV excretion into breast milk was detected. Despite this high rate, symptomatic infection did not occur. However, potential risk and severity of infection may be difficult to establish. Because breastfeeding is beneficial, new procedures for gentle virus inactivation of seropositive breast milk should be assessed.

Low rate of Candida parapsilosis-related colonization and infection in hospitalized preterm infants: a one-year prospective study

We determined the rate of Candida parapsilosis colonization in preterm neonates (NN) and the relationship between colonization and systemic infection through a prospective study in the Neonatal Intensive Care Unit of a university hospital. All NN born at a gestational age of 32 weeks or less were included. Specimens from rectum, mouth and retro-auricular skin were obtained at admission and weekly thereafter. All samples were inoculated on to Sabouraud agar, CHROMagar and Dixon media. Candida species were identified using API Candida and API 20C. DNA analysis was performed using pulse field gel electrophoresis.Fifty-four patients were included (mean age: 30 +/- 1.5 weeks; mean birthweight: 1347 +/- 301 g; male: 40%). Fungal colonization was detected in 43 (79.6%). Causative agents were C. parapsilosis (N= 7);Malassezia furfur (N= 30);C. albicans (N= 21), C. guillermondii (N= 1). No sample was positive for two different yeasts at the same time. C. parapsilosis colonization included anal (N= 6), buccal (N= 1), and skin (N= 2). The average age at time of colonization was 17.8+/-9.8 days. Neither fungal septicaemia nor death were observed in colonized infants. Two central venous catheters were found to be colonized, one with C. parapsilosis and one with M. furfur. Logistic regression showed a link between colonization and gestational age alone. Three different DNA profiles were observed. This study suggests that in our units, the occurrence of C. parapsilosis colonization is low and bears no relation to systemic infection. The systematic identification of C. parapsilosis carriers for the purposes of isolation and preventive treatment does not appear to be warranted.

[Vertical transmission of human coronavirus. Prospective pilot study]

Les coronavirus humains (HCoV) ont été impliqués dans la survenue d'infections respiratoires nosocomiales chez les nouveau-nés. Plusieurs cas d'infections néonatales ont été mis en évidence. Cette étude pilote recherche l'existence d'une éventuelle transmission maternofœtale des HCoV pouvant expliquer les cas infections néonatales observées dans les premières 24 heures de vie.

Matériel et méthode

Étude monocentrique prospective pilote. Étude des couples mère–enfant par la réalisation de trois prélèvements : vaginal et respiratoire chez la mère (VM et RM) lors du travail, gastrique chez le nouveau-né (GNN). Suivi clinique des nouveau-nés et des mères jusqu'à j3. Analyse virologique des échantillons par reverse transcription-polymerase chain reaction (RT-PCR) en temps réel pour la recherche des HCoV 229-E et OC43.

Résultats

Cent cinquante-neuf couples mère–enfant ont été inclus de juillet 2003 à août 2005. Seul HCoV 229-E a été détecté dans 11 échantillons chez six couples mère–enfant. Pour deux couples, les trois prélèvements (VM, RM et GNN) étaient positifs (cas 1 et 2). Pour le cas 3, seuls le VM et GNN étaient positifs. Pour deux couples, seuls les RM étaient positifs (cas 4 et 5). Pour le cas 6, seul le VM était positif. Pour les trois GNN positifs, aucun enfant n'était symptomatique.

Conclusion

Une possible transmission verticale des HCoV est mise en évidence dans cette étude pilote qui nécessite désormais d'être poursuivie à plus large échelle. Il convient également d'inclure la recherche des coronavirus humains identifiés récemment, HCoV NL63 et HKU1, et d'analyser le profil génomique des HCoV détectés chez les trois couples mère–enfant positifs.

[Transitory hyperinsulinism with hypoglycemia in asphyxia neonatorum]

BACKGROUND

Hypoglycemia is a well-known complication in neonates small for gestational age and in those with diabetic mothers. Birth asphyxiated infants can develop severe hypoglycemia due to reduced glycogen stores.

CASE REPORTS

The first patient was born at 41 weeks, weighing 3,780 g by emergency cesarean section because of fetal distress. He developed a pneumothorax and hypoglycemia. He was given glucose infusion (at day 4: 20 mg/kg/d). Hyperinsulinism was confirmed: blood levels at 18.3 mU/L on day 1 and 11.7 mU/L on day 2. The infusion rate was gradually decreased. The second patient was born at 39 weeks, weighing 2,780 g by emergency cesarean section because of fetal distress. She needed glucose infusion (24 g/kg/d) because of hypoglycemia with hyperinsulinism (12.8 mU/L on day 2 and 11.7 mU/L on day 3). After 5 days, the infusion of glucose was replaced by oral feeding only.

CONCLUSION

Transient hypoglycemia in asphyxiated newborn infants with hyperinsulinism must be considered even when hypoglycemia may be difficult to prove.

[Current events in vaccination]

The annual meeting of the Infectious Disease Society of America (IDSA) ; which brought together nearly 5000 participants from over 80 countries in Vancouver, Canada, October 21 to 24, 2010 ; provided a review of the influenza (H1N1) 2009 pandemic, evaluated vaccination programmes and presented new vaccines under development. With 12,500 deaths in the United States in 2009-2010, the influenza (H1N1) 2009 pandemic was actually less deadly than the seasonal flu. But it essentially hit the young, and the toll calculated in years of life lost is high. The monovalent vaccines, whether live attenuated or inactivated with or without adjuvants, were well tolerated in toddlers, children, adults and pregnant women. In order to protect infants against pertussis, family members are urged to get their booster shots. The introduction of the 13-valent Pneumococcal conjugated vaccine in the beginning of 2010 may solve - but for how long ? - the problem of serotype replacement, responsible for the re-increasing incidence of invasive Pneumococcal infections observed in countries that had introduced the 7-valent vaccine. The efficacy of a rotavirus vaccine has been confirmed, with a reduction in hospitalization in the United States and a reduction in gastroenteritis-related deaths in Mexico. In the United States, vaccination of pre-adolescents against human papillomavirus (HPV) has not resulted in any specific undesirable effects. Routine vaccination against chicken pox, recommended since 1995, has not had an impact on the evolution of the incidence of shingles. Vaccination against shingles, recommended in the United States for subjects 60 years and over, shows an effectiveness of 55 %, according to a cohort study (Kaiser Permanente, Southern California). Although some propose the development of personalized vaccines according to individual genetic characteristics, the priority remains with increasing vaccine coverage, not only in infants but also in adults and the elderly. Vaccine calendars that cover a whole lifetime should be promoted, since the vaccination of adults and seniors is a determining factor of good health at all ages.