[Viral respiratory tract infections in the Neonatal Intensive Care Unit]

Prevalence and seasonality of viral respiratory infections in a temperate climate region: A 24-year study (1997-2020)

Background

Few long‐term reports have been published on the epidemiology of respiratory viruses despite their frequent involvement in extremely common infections. The aim here was to determine the frequency and distribution of respiratory viruses in a temperate climate area (Barcelona, Spain) throughout a 24‐year period.

Methods

We collected data on all respiratory viruses detected from 1997 to 2020 in our institution. Clinical specimens were analyzed mainly by conventional techniques, and molecular techniques were also used.

Results

Of the 59,579 specimens analyzed, 21,382 (35.9%) were positive for at least one virus. The number of positive samples during cold months was significantly higher than in warm months. Respiratory virus infections were detected in patients of all ages, above all in children under 3 years of age, who were most frequently infected with the respiratory syncytial virus, whereas Influenza A virus predominated in the other groups, especially in adults. A clear demographic and seasonal pattern was established for some viruses. Circulation of other respiratory viruses during the FLUAV H1N1pdm09 and SARS‐CoV‐2 pandemics was observed.

Conclusions

This long‐term study provides new knowledge about the prevalence of respiratory viruses in a Mediterranean region. Throughout the study period, the frequency of some viruses remained constant, whereas others varied with the year. A clear demographic and seasonal pattern was established for some viruses. Patients suffering from severe respiratory infections should be examined for a range of respiratory viruses regardless of gender, age, or season.

Salivary cytokine - A non-invasive predictor for bronchopulmonary dysplasia in premature neonates

BACKGROUND

To find a less invasive method of cytokine detection for premature neonates, we conducted this cohort study to investigate the salivary cytokines and to analyze their correlations with bronchopulmonary dysplasia (BPD).

METHODS

Premature neonates younger than 34 weeks of gestational age without maternal or neonatal infection were recruited. Salivary samples were collected on their first (D1) and seventh (D7) days of life. The cytokine levels were detected by MILLPLEX® MAP Human multiplex assay. One-way analysis of variance, the Kruskal-Wallis test, Pearson's chi-square test, and logistic regression were used to analyze the data.

RESULTS

Totally 125 neonates were enrolled and separated into four groups: control, mild, moderate, and severe BPD group. The salivary levels of D1 interleukin (IL)-6, IL-8, IL-10, IL-17, interferon (IFN)-γ, and D7 IL-6 (p = 0.001, 0.001, 0.000, 0.043, 0.037 and 0.001, respectively) were significantly higher in the BPD groups than in the control group. After adjusting for the gestational age, acid-base equivalent, and absolute neutrophil count, comparing to the control group, the levels of D7 IL-17 became significantly lower in all three BPD groups (p = 0.032, 0.030, and 0.030, respectively) and that of D7 IFN-α2 became significantly lower in the severe BPD group (p = 0.037).

CONCLUSION

Early-life salivary cytokine levels were correlated with the development of BPD in premature neonates. This study provides a novel method to predict BPD early and non-invasively.

Respiratory morbidity associated with viral respiratory infections during neonatal stage in premature infants

BACKGROUND AND OBJECTIVE

Very low birth weight (VLBW) infants are highly susceptible to viral respiratory infections (VRIs), even during admission to the neonatal intensive care unit (NICU). Although the role of VRI in childhood in the development of recurrent wheezing and long-term asthma is well known, information on the impact in later morbidity of VRI in the neonatal period is lacking. We aimed to explore the occurrence of recurrent wheezing over the first 2 years of life according to VRI status during NICU admission.

METHODS

During April 2016 and December 2017, infants below 32 weeks of gestation were prospectively studied in VRI surveillance during NICU admission. Families were contacted between September 2018 and May 2019 by a telephone questionnaire.

RESULTS

A total of 99 patients were enrolled. The mean gestational age and birth weight were 28.8 (1.9) weeks and 1118 (329) g, respectively. During the first 2 years of life, neither episodes of wheezing nor the respiratory impairment-related hospital admissions differed between positive and negative VRI infants. Episodes of wheezing and respiratory impairment-related hospital admissions, as well as specific respiratory treatment prescription, were more frequent within the first 2 years in infants who had suffered symptomatic VRI during NICU admission.

CONCLUSION

Symptomatic VRI in VLBW infants is associated with long-term respiratory morbidity. The early surveillance of VRI in the preterm infant during NICU admission is justified for prognostic counseling and closely monitoring after discharge. Routine instruction on asthma-related risk factors and early prescription of antiasthmatic treatments, when indicated, should be established.

Respiratory pathogens in infants less than two months old hospitalized with acute respiratory infection

Lower acute respiratory infections (ARI) are a frequent cause of morbidity and mortality in infants, respiratory viruses being the major causative agents. The aim of this work was to determine the respiratory pathogen frequency, the clinical characteristics and the outcome in infants <2 months old hospitalized with ARI. A retrospective study was performed during a five-year period (2008-2011, 2014-2016). Respiratory viruses and atypical bacteria were studied using the FilmArray-Respiratory Panel. Demographic and clinical characteristics, hospitalization course and outcomes were evaluated. Of the 137 infants <2 months old hospitalized with ARI studied, a 94.9% positivity rate as determined in 117 infants with community-acquired infection and 20.0% in 20 infants who acquired the infection during their birth hospitalization in the neonatal intensive care units (NICU) (nosocomial ARI) (p<0.001). In infants with community-acquired infection, Respiratory syncytial virus (RSV) (52.1%) and Rhinovirus/Enterovirus (RV/EV) (41.0%) were the most frequent detected pathogens. Coinfections were determined in one quarter of the infants, RSV-RV/EV being the most frequent combination. In infants with nosocomial infection, RV/EV, RSV or Parainfluenza-3 were detected as single pathogens. Most infants with community-acquired infection presented lower ARI (81.2%) while most infants in the NICU had upper ARI (55.0%). The median length of stay (LOS) in infants with community-acquired ARI was 4 days (IQR: 2-6). Positive infants with nosocomial infection had longer median LOS (71 days [IQR:42-99]) compared to negative infants (58 days [IQR: 49-71]) (p=0.507). Respiratory viruses were detected as the major causative agents of community-acquired infection in hospitalized infants <2-months old, RSV and RV/EV being the most frequently detected. Although a low pathogen positivity rate was observed in infants with nosocomial infection, they may prolong the LOS.

Viral respiratory infections in very low birthweight infants at neonatal intensive care unit: prospective observational study

BACKGROUND AND OBJECTIVE

Very low birthweight (VLBW) infants are highly susceptible to respiratory infections. Information about prevalence of viral respiratory infections (VRIs) in neonatal intensive care unit (NICU) is scarce. Recent evidence suggests short-term and long-term impact of VRI in morbidity of VLBW infants. The goal of this study is to conduct a VRI surveillance in VLBW infants during NICU admission to address the prevalence, type of viruses and associated clinical features.

METHODS

Prospective observational cohort study on infants below 32 gestational weeks admitted to a tertiary NICU during a 2-year period. Respiratory virus detection (influenza, parainfluenza, rhinovirus (hRV), enterovirus, respiratory syncytial virus, metapneumovirus, coronavirus, bocavirus and adenovirus) was performed by real time multiplex PCR assays in nasopharyngeal aspirates (NPAs), within the first 72 hours after birth and weekly, until discharge. Additional samples were taken if clinically indicated.

RESULTS

147 out of 224 eligible infants were enrolled. At least one positive NPA was found in 38% of the study cohort. Main viruses identified were hRV (58%) and adenovirus (31%). Among the 56 infants with positive NPA, 26 showed non-specific respiratory features in 58% (increased respiratory workload, tachypnoea, apnoea) or typical cold features in 38% (rhinorrhea, cough, fever), at least in one episode. Antibiotics were prescribed in 29% of cases. Positive infants showed higher rates of bronchopulmonary dysplasia (BPD), need for supplemental oxygen and mechanical ventilation, and had longer hospital stay. Cox regression analysis found BPD as an independent risk factor for viral infection (p<0.001) and symptomatic VRI (p<0.04).

CONCLUSIONS

Systematic surveillance in VLBW infants reports VRI is frequent, particularly by hRV. Asymptomatic infection is highly prevalent which is critical in the face of establishing appropriate preventive strategies. Infants with BPD are especially vulnerable to such infections.

Focusing on Families and Visitors Reduces Healthcare Associated Respiratory Viral Infections in a Neonatal Intensive Care Unit

Supplemental Digital Content is available in the text.

Healthcare-associated respiratory viral infections (HARVIs) result in significant harm to infants in the neonatal intensive care unit (NICU). Healthcare workers and visitors can serve as transmission vectors to patients. We hypothesized that improved family and visitor hand hygiene (FVHH) and visitor screening would reduce HARVIs by at least 25%.

Hospital-acquired viral respiratory infections in neonates hospitalized since birth in a tertiary neonatal intensive care unit

OBJECTIVE

To determine frequency of hospital-acquired viral respiratory infections (HA-VRI) and associated outcomes in a NICU.

STUDY DESIGN

Prospective cohort study conducted from 4 October 2016 to 21 March 2017. Infants hospitalized from birth in the NICU had a weekly nasal swab collected for testing using a multiplex PCR assay capable of detecting 16 different respiratory viruses.

RESULTS

Seventy-four infants enrolled, with 5 (6.8%) testing positive for a virus (incidence rate of 1.3/1000 patient days). VRI positive infants had a younger gestational age (median 27 w vs. 32 w, p = 0.048); were hospitalized longer (97 d vs 43 d, p = 0.013); required more antibiotics (8 d vs. 4 d, p = 0.037) and were more likely to be diagnosed with bronchopulmonary dysplasia (p = 0.008) compared to VRI negative infants.

CONCLUSION

Respiratory viruses are a frequent cause of HAI in the NICU and are associated with negative outcomes.

The impact of respiratory viruses on lung health after preterm birth

Children born preterm, less than 37 weeks' gestation, are at increased risk of viral respiratory infections and associated complications both during their initial birth hospitalisation and in their first years following discharge. This increased burden of viral respiratory infections is likely to have long term implications for lung health and function in individuals born preterm, particularly those with bronchopulmonary dysplasia. Several hypotheses have been put forward to explain the association between early life viral respiratory infection and development of suboptimal lung health and function later in life following preterm birth. Although preterm infants with diminished lung function, particularly small airways, might be particularly susceptible to asthma and wheezing disorders following viral infection, there is evidence that respiratory viruses can activate number of inflammatory and airway re-modelling pathways. Therefore, the aim of this review is to highlight the perinatal and early life risk factors that may contribute to increased susceptibility to viral respiratory infections among preterm infants during early life and to understand how respiratory viral infection may influence the development of abnormal lung health and function later in life.

Nosocomial Transmission and Genetic Diversity of Rhinovirus in a Neonatal Intensive Care Unit

Rhinoviruses were detected as sole pathogens in 6 preterm infants who developed severe respiratory infections while hospitalized in a neonatal intensive care unit. We confirmed 2 nosocomial rhinovirus transmission episodes and describe the genetic diversity of rhinovirus strains that circulated simultaneously during a winter season.

[Rhinovirus: Underestimated pathogens in patients during the neonatal period]

INTRODUCTION

In recent years, developments in virological tools have led to the easy detection of rhinoviruses and enteroviruses (E/RV). Their detection is very frequent in cases of airway involvement in children and their demonstrated causality. But the morbidity of E/RV in the neonatal period is unknown due to lack of epidemiological data. The objective of this study was to evaluate the incidence and clinical characteristics of these infections in hospitalized neonates.

MATERIALS AND METHODS

We retrospectively analyzed the virology specimens of all neonates hospitalized at the Caen University Hospital between 2006 and 2011. Clinical characteristics were obtained from the charts.

RESULTS

During the study period, 4544 infants aged less than 28 days were hospitalized: 4159 in the neonatal ward and 385 in the pediatric ward. Among these, 711 virology specimens were available, 31 % of which identified at least one virus. An E/RV was identified in 87 patients (1.9 % of the neonates admitted during the study period): 52 in the pediatric ward (13.5 % of 385), and 35 in the neonatal ward (0.8 % of 4159). The mean gestational age was 39 weeks in the pediatric cohort and 35 weeks in the neonatal cohort. The main indication for virological analysis was persistent drowsiness (28 %), temperature above 38°C (25 %), an apparently life-threatening event (23 %), bradycardia (20.5 %), and pallor (20.5 %). Respiratory symptoms associated with E/RV infection were coryza (74 %), cough (35 %), hypoxemia (32 %), accessory muscle use, and recession (31 %). Digestive symptoms were poor feeding (59 %), regurgitation (38 %), abdominal distension (24 %), and projectile vomiting (17 %). Twenty-three percent of the patients required admission to the neonatal ICU or pediatric ICU. Respiratory treatments included oxygen (24 % of 87 patients), continuous positive airway pressure (11 %), and ventilation (5 %). Antibiotics were prescribed in 41 % of the patients (46), but only 10 % (9) had an identified concomitant bacterial infection. In the neonatal department, nosocomial acquisition was suspected in 50 % of E/RV infections.

CONCLUSION

E/RV infections have a significant morbidity in neonates, and nosocomial transmission of the virus is underestimated. We recommend that respiratory viruses, including E/RV, be tested for in any unexplained signs in a neonate. Better identification of viruses might shorten the duration of unnecessary antibiotics.

Viral Infections in Neonates with Suspected Late-Onset Bacterial Sepsis-A Prospective Cohort Study

Objective The aim of our study was to evaluate the occurrence of viral infections in infants with suspected late-onset bacterial sepsis in a neonatal intensive care unit. Methods In a prospective study, infants with suspected late-onset bacterial sepsis underwent viral testing alongside routine blood culture sampling. Using a multiplex reverse transcription-polymerase chain reaction enzyme-linked immunosorbent assay, nasopharyngeal aspirates were analyzed for adenovirus, respiratory syncytial virus (RSV), influenza virus A and B, H1N1 virus, parainfluenza virus 1 to 4, metapneumovirus, coronavirus, and picornavirus. Stools were examined for adenovirus, rotavirus, norovirus, and enterovirus. Results Between August 2010 and March 2014, data of 88 infants with 137 episodes of suspected late-onset bacterial sepsis were analyzed. Six infants were diagnosed with a respiratory viral infection (2 × RSV, 4 × picornavirus). Blood culture-proven bacterial sepsis was detected in 15 infants. Neither viral-bacterial coinfections nor polymerase chain reaction positive stool samples were found. Conclusion Respiratory viruses can be detected in a considerable number of neonates with suspected late-onset bacterial sepsis. In contrast, gastrointestinal viral or enterovirus infections appear uncommon in such cases.

Outcomes of Nosocomial Viral Respiratory Infections in High-Risk Neonates

BACKGROUND AND OBJECTIVE

Neonatal respiratory disease, particularly bronchopulmonary dysplasia, remains one of the leading causes of morbidity and mortality in newborn infants. Recent evidence suggests nosocomially acquired viral respiratory tract infections (VRTIs) are not uncommon in the NICU. The goal of this study was to assess the association between nosocomial VRTIs, neonatal respiratory disease, and the health care related costs.

METHODS

A matched case-control study was conducted in 2 tertiary NICUs during a 6-year period in Nottingham, United Kingdom. Case subjects were symptomatic neonatal patients with a confirmed real-time polymerase chain reaction diagnosis of a VRTI. Matched controls had never tested positive for a VRTI. Multivariable logistic regression was used to test for associations with key respiratory outcomes.

RESULTS

There were 7995 admissions during the study period, with 92 case subjects matched to 183 control subjects. Baseline characteristics were similar, with a median gestation of 29 weeks. Rhinovirus was found in 74% of VRTIs. During VRTIs, 51% of infants needed escalation of respiratory support, and case subjects required significantly more respiratory pressure support overall (25 vs 7 days; P < .001). Case subjects spent longer in the hospital (76 vs 41 days; P < .001), twice as many required home oxygen (37%; odds ratio: 3.94 [95% confidence interval: 1.92-8.06]; P < .001), and in-hospital care costs were significantly higher (£49 664 [$71 861] vs £22 155 [$32 057]; P < .001).

CONCLUSIONS

Nosocomial VRTIs in neonatal patients are associated with significant greater respiratory morbidity and health care costs. Prevention efforts must be explored.