Risk Factors For Respiratory Syncytial Virus Infection Research Articles

Population-based serology reveals risk factors for RSV infection in children younger than 5\xa0years

Respiratory syncytial virus (RSV) infection is a leading cause of hospitalization in infants. Underlying risk factors for RSV infection in the general population are not well understood, as previous work has focused on severe outcomes of infection in a clinical setting. Here we use RSV-specific IgG and IgA antibody measurements from two population-based cross-sectional serosurveys carried out in the Netherlands (n = 682) to classify children up to 5 years as seronegative or seropositive. We employ a generalized additive model to estimate the probability of prior RSV infection as function of age, date of birth within the year, and other risk factors. The analyses show that the majority of children have experienced a RSV infection before the age of 2 years. Age and birthdate are strong predictors of RSV infection in the first years of life, and children born in summer have higher estimated probability of infection than those born in winter [e.g., 0.56 (95% CI 0.45–0.66) vs. 0.32 (0.21–0.45) at age 1 year]. Our analyses reveal that the mean age at infection depends on date of birth, which has implications for the design of vaccination programmes and prioritisation schemes for the prophylactic use of monoclonal antibodies.

Microbiome-Transcriptome Interactions Related to Severity of Respiratory Syncytial Virus Infection

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections and hospital visits during infancy and childhood. Although risk factors for RSV infection have been identified, the role of microbial species in the respiratory tract is only partially known. We aimed to understand the impact of interactions between the nasal microbiome and host transcriptome on the severity and clinical outcomes of RSV infection. We used 16 S rRNA sequencing to characterize the nasal microbiome of infants with RSV infection. We used RNA sequencing to interrogate the transcriptome of CD4+ T cells obtained from the same set of infants. After dimension reduction through principal component (PC) analysis, we performed an integrative analysis to identify significant co-variation between microbial clade and gene expression PCs. We then employed LIONESS (Linear Interpolation to Obtain Network Estimates for Single Samples) to estimate the clade-gene association patterns for each infant. Our network-based integrative analysis identified several clade-gene associations significantly related to the severity of RSV infection. The microbial taxa with the highest loadings in the implicated clade PCs included Moraxella, Corynebacterium, Streptococcus, Haemophilus influenzae, and Staphylococcus. Interestingly, many of the genes with the highest loadings in the implicated gene PCs are encoded in mitochondrial DNA, while others are involved in the host immune response. This study on microbiome-transcriptome interactions provides insights into how the host immune system mounts a response against RSV and specific infectious agents in nasal microbiota.

Epidemiology, Risk Factors, and Outcomes of Respiratory Syncytial Virus Infections in Newborns in Bamako, Mali.

BackgroundFew studies describe the respiratory syncytial virus (RSV) burden in African populations, and most have utilized hospital-based surveillance. In Mali, no community-based studies exist of the incidence or epidemiology of RSV infection. This study provides the first estimates of RSV incidence in Mali.MethodsIn a cohort of infants enrolled in a clinical trial of maternal influenza vaccination, we estimate incidence of RSV-associated febrile illness in the first 6 months of life and identify risk factors for RSV infection and progression to severe disease. Infants (N = 1871) were followed from birth to 6 months of age and visited weekly to detect pneumonia and influenza-like illness. Baseline covariates were explored as risk factors for RSV febrile illness and RSV pneumonia or hospitalization.ResultsIncidence of RSV illness was estimated at 536.8 per 1000 person-years, and 86% (131/153) of RSV illness episodes were positive for RSV-B. RSV illness was most frequent in the fifth month of life and associated with having older mothers and with lower parity. The incidence of RSV-associated hospitalizations was 45.6 per 1000 person-years. Among infants with RSV illness, males were more likely to be hospitalized. The incidence of RSV pneumonia was 29 cases per 1000 person-years.ConclusionsIn the first 6 months of life, Malian infants have a high incidence of RSV illness, primarily caused by RSV-B. Prevention of early RSV will require passive protection via maternal immunization in pregnancy. Mali is the first country where RSV-B has been identified as the dominant subtype, with potential implications for vaccine development.

Risk factors of respiratory syncytial virus infection among pediatric influenza-like illness and severe acute respiratory infections in Suzhou, China.

The characteristics and risk factors of respiratory syncytial virus (RSV) infection among children has not yet been fully understood. To address the characteristics of RSV-associated illness and risk factors of RSV infection among children under 5 years of age in Suzhou, China. From April 2011 to March 2014, we conducted a prospective surveillance among children in Suzhou, China. Nasal or throat swabs were collected from outpatients with influenza-like illness (ILI) and inpatients with severe acute respiratory infections (SARI). RSV was detected by reverse-transcriptase polymerase chain reaction and direct fluorescent antibody assay for children with ILI and SARI, respectively. Multivariable logistic-regression models were constructed to explore risk factors and symptoms of RSV infection. Of 3267 ILI and 1838 SARI children enrolled in the study, 192 (5.9%) and 287 (15.6%) tested positive for RSV, respectively. Among ILI patients, children with RSV infections visited clinics more often (P = 0.005) and had longer duration of fever (P = 0.032) than those without RSV infection. All RSV-positive children had an increased risk of having cough (OR = 2.9), rhinorrhea (OR = 1.6), breathing difficulty (OR = 3.4), wheezing (OR = 3.3), and irritability (OR = 2.7). Children aged <2 years, had history of prematurity (OR = 2.0) and recent respiratory infections (OR = 1.3) were more likely to get infected by RSV. Children with SARI had higher positive rate of RSV than those with ILI. Cough, rhinorrhea, and wheezing were the most common symptoms in RSV infection. Children aged <2 years, had history of prematurity and recent respiratory infections were the potential risk factors for RSV infection.

RESPIRATORY SYNCYTIAL VIRUS INFECTION IN INFANTS

The review focuses on respiratory syncytial virus infection (RSVI) and, based on the literature and authors' own observations, highlights epidemiological aspects and risk factors for RSVI (including severe forms of the infection), the specific clinical manifestations, challenges of laboratory diagnostics, and the benefits of various methods and their relevance in clinical practice. The available types of RSVI therapies are discussed based on meta-analyses of the data. The authors emphasize the importance of palivizumab in the specific passive prevention of respiratory syncytial virus infection in children from risk groups.

Clinical characteristics and outcome of respiratory syncytial virus infection among adults hospitalized with influenza-like illness in France

ObjectivesThe aim of this study was to analyse characteristics and outcome of respiratory syncytial virus (RSV) infection in adults hospitalized with influenza-like illness (ILI). MethodsPatients hospitalized with ILI were included in this prospective, multicentre study carried out in six French hospitals during three consecutive influenza seasons (2012–2015). RSV and other respiratory viruses were detected by multiplex PCR in nasopharyngeal swabs. Risk factors for RSV infection were identified by backward stepwise logistic regression analysis. ResultsA total of 1452 patients hospitalized with ILI were included, of whom 59% (861/1452) were >65 years and 83% (1211/1452) had underlying chronic illnesses. RSV was detected in 4% (59/1452), and influenza virus in 39% (566/1452). Risk factors for RSV infection were cancer (adjusted OR 2.1, 95% CI 1.1–4.1, p 0.04), and immunosuppressive treatment (adjusted OR 2.0, 95% CI 1.1–3.8, p 0.03). Patients with RSV had a median length of stay of 9 days (6–25), and 57% of them (30/53) had complications, including pneumonia (23/53, 44%) and respiratory failure (15/53, 28%). Fifteen per cent (8/53) were admitted to an intensive care unit, and the in-hospital mortality rate was 8% (4/53). Pneumonia was more likely to occur in patients with RSV than in patients with RSV-negative ILI (44% (23/53) versus 26% (362/1393), p 0.006) or with influenza virus infection (44% versus 28% (157/560), p 0.02). ConclusionRSV is an infrequent cause of ILI during periods of influenza virus circulation but can cause severe complications in hospitalized adults. Risk factors for RSV detection in adults hospitalized with ILI include cancer and immunosuppressive treatment. Specific immunization and antiviral therapy might benefit patients at risk.

Relative frequency, Possible Risk Factors, Viral Codetection Rates, and Seasonality of Respiratory Syncytial Virus Among Children With Lower Respiratory Tract Infection in Northeastern Brazil.

Few studies, each limited to a single major city, have investigated the prevalence and seasonal patterns of different viruses among children with low respiratory tract infections (LRTI) in Northeastern Brazil. The aim of this study was to determine the frequency of respiratory syncytial virus (RSV) and of 7 other viruses in children for LRTI in 4 capitals from this region, and investigate their association with several risk factors, including meteorological data.From April 2012 to March 2013, 507 children, aged up to 24 months and hospitalized with LRTI in one of the participating centers at Aracajú, Salvador, Recife, and Maceió, had a sample of nasopharyngeal aspirate collected and analyzed for the following viruses by reverse-transcription polymerase chain reaction followed by hybridization on low-density microarrays: RSV, influenza, parainfluenza, adenovirus, rhinovirus, metapneumovirus, bocavirus, and coronavirus.The result was positive in 66.5% of cases, RSV was the most common virus (40.2%). Except for rhinovirus (17%), all other virus had frequency rates lower than 6%. Viral coinfections were detected in 13.8% of samples. Possible related risk factors for RSV infection were low age upon entry, attendance of daycare, low gestational age, and low educational level of the father. The relative frequency of viral infections was associated with increasing temperature and decreasing humidity separately, but the results also suggested both associated with increased frequency of RSV. Some of these findings differ from those reported for other regions in Brazil and may be used to guide policies that address LRTI.

Brote por virus respiratorio sincitial en la Unidad de Neonatología de un hospital de tercer nivel

IntroductionInvestigation and control of a respiratory syncytial virus (RSV) outbreak that affected the Neonatal Intensive Care Unit (NICU) of a university hospital from October to December 2012. Patients and methodsCohort study of children admitted to the NICU. The infection attack rate was calculated. A descriptive analysis of the cases and a multivariate analysis was performed using the variables that were shown to be risk factors for RSV infection.Preventive measures taken were: contact isolation; hand hygiene training and observation; exclusivity of a health team of nurses and physicians for positive cases, restrictions on visitor numbers; surveillance RSV testing, and palivizumab prophylaxis. ResultsThe outbreak had three epidemic waves and 20 positive cases out of a total of 48 children admitted. The overall attack rate was 42%. Half of positive cases were children, with a median age of 36 days (p25=22, p75=58). The independent risk factors for RSV infection were birth weight below 1000 grams (OR=23.5; P=.002) and to have another nosocomial infection the week before the diagnosis of RSV infection (OR=19.98; P=.016). ConclusionsIt was an outbreak with a high number of cases, due to the delay in notification, prolonged RSV carrier status, and low adherence to hand hygiene practice, which favoured the cross-transmission of infection. The most effective preventive measures were direct observation of hand hygiene and supervision of isolation measures.

Virus respiratorio sincicial. Patrón clínico epidemiológico en niños internados en un hospital pediátrico durante los años 2000-2013

Respiratory syncytial virus (RSV) is the major causative organism associated with acute lower respiratory tract infections in children.The objective of this study was to describe the clinical and epidemiological pattern of RSV and identify risk factors for RSV infection. Prospective, cohort study on patients hospitalized due to acute lower respiratory tract infection at Hospital de Niños Ricardo Gutiérrez between March and November throughout the 2000-2013 period. The virological diagnosis of RSV, adenovirus, influenza and parainfluenza was performed by indirect immunofluorescence using nasopharyngeal aspirates. A total of 12,555 children were included, 38.2% (4798) had virus rescued from samples. RSV accounted for 81.8% of cases (3924/4798) with no significant annual variations (71.2- 88.1) and with an epidemic seasonal pattern(May through July); RSV was followed by influenza (7.6%), parainfluenza (5.9%), and adenovirus (4.7%).The median age of patients with RSV rescue (3924) was 7 months old (0- 214 months old), while 74.2% were younger than 1 year old, 43.1% were younger than 6 months old, 56.5% were males and the most common clinical presentation was bronchiolitis (60.7%). Comorbidities were observed in 41.6% of cases. The most common comorbidities were chronic respiratory disease (74%), congenital heart disease (14%), and chronic neurological disease (10.2%).Complications occurred in 25%of cases. The case fatality rate was 1.9% (74/3888). Independent predictors of RSV infection were age <3 months old (OR: 2.8 [2.14-3.67], p < 0.01),clinical presentation of bronchiolitis (OR: 1.54 [1.32-1.79], p < 0.01), and hypoxemia at the time of admission (OR: 1.84 [1.42-2.37], p < 0.01). RSV infection displayed a seasonal pattern and was associated with infants younger than 3 months old with bronchiolitis and hypoxemia at the time of admission.

Contributing and Terminating Factors of a Large RSV Outbreak in an Adult Hematology and Transplant Unit.

BACKGROUND: In January 2012, an increase of respiratory syncytial virus (RSV) infections on an adult hematology and transplant unit in a German university hospital was detected. We investigated the outbreak to assess its timing and extent and to identify risk factors for transmission.METHODS: We tested and typed patient samples pro- and retrospectively for RSV. We conducted a cohort and a case-control study. A confirmed outbreak case had laboratory-diagnosed, nosocomially-acquired RSV infection. Possible outbreak cases had pneumonia but were not laboratory-confirmed.RESULTS: Of 53 outbreak cases, 36 (68%) were confirmed and 17 (32%) possible. Retrospective testing and chart review dated the beginning of the outbreak to November 2011. Patients with community-acquired RSV infection were identified when the community epidemic began in January 2012. In multivariable analysis (controlling for contact with medical personnel, hygiene behaviour and age) patients with active social behaviour were more at risk for RSV infection (odds ratio 23.8, 95% confidence interval, 1.3 to 434.9; p-value, 0.03). Confirmed outbreak cases were more likely than controls to have been accomodated together with a confirmed or possible case before their onset of illness (OR 9.3, 95%CI: 2.1-85.1; p<0.001). Control measures, including isolation of every patient in the unit, initiated until the end of January terminated the outbreak.CONCLUSIONS: Epidemiological investigations revealed co-accomodation with a case-patient and active social behaviour as likely risk factors for RSV infection. Awareness of and vigorous testing for respiratory viruses in immunosuppressed hospitalised patients is necessary to timely detect cases with outbreak potential. Isolation of patients with respiratory infectious illnesses is crucial to prevent the continuation or occurrence of outbreaks.

Risk factors of hospitalization for lower respiratory tract infections in infants with 33 weeks of gestational age or more: a prospective Italian cohort study on 2210 newborns

Lower respiratory tract infections (LRTI) caused by the Respiratory Syncytial Virus (RSV) represent the major cause of hospitalization among young children, especially infants under 12 months of age [1]. Children at high risk of hospitalization for RSV-LRTI include preterm infants [2] and infants who are affected by chronic lung disease (CLD), congenital heart disease (CHD), immunodeficiency and neuromuscular disorders [3]. For these high-risk infants, RSV prophylaxis with humanized RSV monoclonal antibodies (palivizumab) is effective in reducing the risk of developing severe RSV infections and hospitalization [4]. Several epidemiological studies have found other determinants of severe RSV infections [5] but results show variability, probably because performed in different countries or with alternation in the RSV epidemic season, and even for the different methodologies adopted. Several potential risk conditions are identified to be age at the time of RSV infection or birth early during the RSV season, younger age, male gender, day care attendance, presence of siblings, household crowding, exposure to tobacco smoke or to air pollution, and lack of breastfeeding [6–9]. Despite several epidemiological studies have identified some risk factors for RSV infection in preterm babies, only few epidemiological data in healthy and at term infants are available. Aim of this study was to evaluate the role of prenatal, perinatal and postnatal/

Outcomes of palivizumab prophylaxis for respiratory syncytial virus infection in preterm children with bronchopulmonary dysplasia at a single hospital in Korea from 2005 to 2009.

This study was performed to evaluate the utilization and outcomes of palivizumab in high risk children born prematurely with chronic lung disease (CLD). A retrospective review of 128 patients was conducted from September 2004 to March 2009 at the Ajou University Hospital. All patients were diagnosed with CLD, were born at ≤35 weeks of gestation, were <2 yr old at the onset of respiratory syncytial virus (RSV) season, and had received medical therapy within six months prior to the RSV season. Fifty-three patients did not receive palivizumab prophylaxis and 75 patients received at least one dose of palivizumab. There were no statistically significant differences between the patients with and without palivizumab prophylaxis with regard to demographic characteristics and risk factors for RSV infection. There were no systemic adverse responses. Compliance with the course of prophylaxis was 92.2%. Hospitalization associated with RSV occurred in 12 cases (22.6%) in the group without prophylaxis and in three cases (4.0%) with prophylaxis. Palivizumab prophylaxis significantly reduced the frequency of RSV-related hospitalization in preterm children with CLD. This is the first retrospective review of palivizumab prophylaxis in Korea. Palivizumab is effective and well tolerated in high risk prematurely born children.

Incidence of Respiratory Syncytial Virus Positivity in Young Italian Children Referred to the Emergency Departments for Lower Respiratory Tract Infection over Two Consecutive Epidemic Seasons

The rate and severity of respiratory syncytial virus (RSV) infections within the same nation may vary from one year to another. The "Osservatorio VRS" study collected epidemiological data on RSV infection among Italian children aged < or = 4 years referred to emergency departments of 14 centers, for suspected lower respiratory tract infections (LRTI) in two consecutive RSV seasons (October 2000-April 2001 and October 2001-April 2002). Medical history and physical examination were recorded and an immunoenzymatic RSV test was performed on nasal secretions. Study variables were collected and evaluated separately, then compared. In all, 272 and 756 children were included in the two seasons, respectively, of which 31.6% and 19.2% were RSV positive (+). Children of the first season had lower gestational and chronological age, higher rates of chronic lung disease (CLD), very low birth weight (< 1,500 g), larger use of corticosteroids or bronchodilators. Main risk factors for RSV infection were a young age (< 1 year) and a low birth weight (< 1,500 g). RSV infection reached its peak in February (first season) or March (second season), with an earlier appearance in the northern and central as compared to the southern regions. Rate of hospitalization and LRTI was higher in RSV+ children, especially if young. Although rhythms of the RSV seasons and patient characteristics may vary from one year to another, the severity of RSV disease in nonprophylaxed infants and young children remains high.

Rehospitalisations for respiratory disease and respiratory syncytial virus infection in preterm infants of 29–36 weeks gestational age

Background To evaluate rates of rehospitalisation due to respiratory illness in preterm infants of 29–36 weeks gestation without chronic lung disease. Patients and methods Retrospective single centre cohort study including infants from 1998 to 1999 with follow-up over two respiratory syncytial virus (RSV) seasons. Results Of 435 infants included 61 infants (14%) experienced 78 rehospitalisations. The overall RSV attack rate was 4.4% over two consecutive RSV seasons for infants below 6 months of age at onset of RSV season (7.7 and 1.1%, respectively, p=0.015), with significant differences between infants of 29–32 and 33–36 weeks gestational age (10.5% vs. 2.3%, p=0.008). None of the infants needed mechanical ventilation or admission to the intensive care unit. Infants with RSV infection were younger of age (mean 4.2 vs. 8.2 months; p=0.015), had longer stays at the hospital (11.5 vs. 7.0 days; p=0.006), and more severe courses of disease (score 3.0 vs. 1.8; p<0.001). Additional risk factors for RSV infection were multiple gestation (OR 5.5; CI 95% 1.439–21.028) and congenital heart disease (OR 4.2; CI 95% 1.005–17.669). Conclusion The total burden of respiratory disease and RSV infection in this population was low. A lower gestational age, multiple gestation, and congenital heart disease were associated with increased risk of RSV infection.