Respiratory Syncytial Virus Antigen Test Research Articles

Platelet to Lymphocyte Ratıo in Respıratory Syncytıal Vırus Infectıon

Introduction: We aim to examine the role of Platelet to lymphocyte ratio (PLR) and Platelet to Lymphocyte and monocyte ratio (PLT/LY+MO) values in Respiratory Syncytial Virus (RSV) infection. Methodology: Complete blood counts and RSV Antigen test results of 76 patients, between the age of 0-12 were investigated retrospectively. PLR values are calculated using Platelet Count / Lymphocyte Count formula, whereas PLMR values are calculated using Platelet Count / Lymphocyte Count + Monocyte Count. Results: Out of 76, 32 patients were diagnosed as RSV infected. Lymphocyte and monocyte percentage and platelet count were significantly higher in RSV positive group. Monocyte percentage in lower respiratory tract RSV infection was significantly lower compared to upper respiratory tract RSV infection. Conclusions: Our study revealed that these blood parameters may be an important clue for the clinician for RSV infection and also play a role as a guide before advanced techniques.

The Scope of Respiratory Syncytial Virus Infection in a Tertiary Hospital in the Eastern Province of Saudi Arabia and the Change in Seasonal Pattern during and after the COVID-19 Pandemic.

Background and Objectives: Respiratory syncytial virus (RSV) is a major cause of morbidity and hospital admission due to respiratory tract infection among infants and young children. The current study aims to describe the prevalence and the seasonal pattern of RSV during the previous seven years. Materials and Methods: Clinical data and RSV antigen and PCR test results were collected from patients' medical records at King Fahd Hospital of the University in the Eastern Province of Saudi Arabia between January 2015 and February 2022. Results: The overall percentage of RSV detection was 26.3% (336/1279) among the tested individuals. RSV infection was more common among children below five years and elderly above 60 years of age. Two-thirds of the cases required hospitalization. The average hospital stay due to RSV infection was 6.5 days (range 0-56 days). The rate of hospitalization was higher among infants and younger children and decreased with age (p-value < 0.001). RSV infection was more prevalent between August and February and decreased appreciably between March and July. The peak level of infection was during December and January. No RSV infections were reported during the COVID-19 pandemic and the following winter. The cases increased again in August 2021, with an unusual out-of-season peak. Conclusions: RSV infection is one of the important causes of morbidity and hospitalization among infants and young children in Saudi Arabia. The seasonal pattern of infection has changed after the COVID-19 pandemic, and the physicians should be aware that infection may happen currently at different times throughout the year.

Quantifying the causal impact of funding bedside antigen testing on the incidence of respiratory syncytial virus infection in Japan: a difference-in-differences study.

BackgroundTo estimate the causal impact of a change in the national health insurance policy to cover the cost of respiratory syncytial virus (RSV) antigen testing on the incidence of RSV infection by age-groups, we analyzed the sentinel datasets of RSV infection in Japan from 2009–2017.MethodsThe causal effect of introducing RSV antigen testing on increasing the reported incidence of RSV infection was quantified using a quasi-experimental difference-in-differences (DID) design and influenza as a control group.ResultsExamining sentinel and virus surveillance datasets, only clinically mild cases have selectively increased from 2012/13. The median estimated incidences of influenza and RSV infection among children aged 0–4 years, the age group that dominates cases of both diseases, were estimated at 5,607 and 1,761 per 100,000 individuals, respectively. Exploring sentinel datasets, only the incidence of RSV infection abruptly increased from 2012/13. Using an age-dependent model, the estimated causal effect on the increase in RSV annual incidence was greatest among children aged 5–9 years, with an estimated additional 1,912 cases per 100,000 individuals (95% CI: 418–3,406).ConclusionsOwing to financial support of bedside RSV antigen testing from 2012/13, the incidence of RSV infection has been elevated. The recent increasing trend in RSV infection incidence should not be directly perceived as an increase in natural infections with RSV.

Evaluation of immuview RSV antigen test (SSI siagnostica) and BinaxNOW RSV card (alere) for rapid detection of respiratory syncytial virus in retrospectively and prospectively collected respiratory samples.

Human orthopneumovirus, formerly known as respiratory syncytial virus (RSV), is a frequent cause of hospitalization among infants due to respiratory tract infection. Fast, reliable, and easy to perform tests are needed to optimize treatment and to identify children that should be contact isolated to avoid nosocomial outbreaks. We prospectively tested 200 respiratory samples with a new assay (ImmuView RSV Antigen Test, SSI Diagnostica) and compared the results to the Alere BinaxNOW RSV Card by using our laboratory-developed real-time reverse transcription polymerase chain reaction (PCR) as reference. In addition, 300 retrospectively collected respiratory samples were included in the study. The sensitivities of both antigen kits were very low (<50%). Sensitivities were higher when samples came from children less than 6 years, when samples came from nasopharynx or lower respiratory airways, or when samples were positive for RSV serotype A compared to when samples came from adults, samples were throat swabs, or samples were positive for RSV serotype B. In conclusion, the ImmuView RSV antigen kit did not perform well and may at the most be used as a quick guidance for clinical decision. Thus, it cannot stand alone without reverse transcription PCR confirmation of negative results.

Perfect Care Across the Continuum of Care.

Another day in the life of a pediatric hospitalist, another bronchiolitis quality improvement project. Or so it seems. In this issue of Hospital Pediatrics , Berg et al1 present a quality improvement project, based on the American Academy of Pediatrics 2014 clinical practice guideline (CPG),2 aimed at decreasing overused interventions across the continuum of care (COC) in urgent care clinics, emergency departments (EDs), and inpatient units. Although similar initiatives have targeted >1 care setting,3,4 this appears to be the broadest effort to date. The other striking innovation of this project is what may be termed a “perfect care metric,” a composite measure of complete CPG adherence, as the primary outcome. To be “completely adherent” to the bronchiolitis CPG, providers must not have ordered any of the following 8 medical interventions: viral panels, respiratory syncytial virus antigen testing, complete blood counts, blood cultures, chest radiographs, antibiotics, albuterol, and systemic steroids. The investigators took advantage of their setting, which comprises 2 freestanding tertiary …

Is the interpretation of rapid antigen testing for respiratory syncytial virus as simple as positive or negative?

ObjectiveTo measure the performance characteristics of an immunochromatographic rapid antigen test for respiratory syncytial virus (RSV) and determine how its interpretation should be contextualised in patients presenting to the emergency...

Hospitalizations Due to Respiratory Syncytial Virus Outside of the Typical Season.

Objective: Respiratory Syncytial Virus (RSV) is the most common cause of bronchiolitis and viral lower respiratory tract infections in children. It is associated with annual winter epidemics across the United States, typically October through April. Our objective is to describe the clinical characteristics of children hospitalized outside the typical RSV season and to compare them with those admitted during the season. Methods: A retrospective chart review was conducted of all patients who were hospitalized at Children's Hospital of Austin from May 2000 to September 2006 and had a positive RSV antigen test. Descriptive statistics, tests of differences, and associations between patients diagnosed in the off-season versus typical season were conducted. Results: A total of 850 charts of RSV-positive cases were reviewed. Of these, 45 patients (5.3%) were admitted during the off-season. The following variables were statistically significantly associated with diagnosis in the off-season versus typical season: mean birth weight (2704 g vs. 3204 g respectively, p=0.0001); gestational age at birth less than 36 weeks (OR=4.35; 95% CI: 2.2, 8.6); history of neonatal intensive care unit (NICU) admission at birth (OR=6.04; 95% CI: 2.9, 12.5); and multiple birth (OR=3.38; 95% CI: 1.2, 9.2). Conclusions: Infants with RSV infection outside of the typical season were more likely to have been premature, of lower birth weight, the products of multiple births, and admitted to the NICU at birth.

Rapid Antigen Testing to Detect Respiratory Syncytial Virus Performs Well in Neonates

Background: Infection with respiratory syncytial virus (RSV) in neonates is associated with significant morbidity and mortality. Early and accurate detection of RSV infection is important for appropriate isolation and cohorting, appropriate antibiotic usage, antiviral treatment, and public health awareness. However, RSV rapid antigen test performance has not been evaluated for neonates. Methods: A retrospective analysis of rapid RSV antigen testing in neonates (≤30 days) using a laboratory database of the Diagnostic Virology Laboratory at Texas Children's Hospital acquired between 1997 and 2008 was performed. Of 3691 respiratory samples collected consecutively, 784 (21%) were positive for RSV by rapid test and 402 (10.9%) showed growth of RSV in viral culture. Sensitivity, specificity, positive predictive values, and negative predictive values were calculated using viral culture as the reference standard. P values were calculated utilizing Pearson chi-square with SPSS Statistics 17.0. Result: Overall sensitivity was 90.3% and specificity was 88.2%. Sensitivity was lower in nonseason samples (76.5% vs. 90.9% [P = 0.048]), but specificity was higher in nonseason samples (95.6% vs. 87.1% [P ≤ 0.001]). Lower specificity was seen in samples submitted from neonates evaluated in the emergency department compared with inpatient floors, neonatal intensive care unit, and unspecified venues (85.1% vs. 95.6%, 94.3%, 95.5%, respectively P ≤ 0.001). Overall, there was no statistical difference in test performance based on specimen type. However, when RSV was in season, nasal washes were more sensitive than tracheal aspirates (P = 0.017). Conclusions: Rapid RSV antigen testing was sensitive and specific in detecting RSV infections in neonates. Moderate differences in test performance occurred in and out of RSV season, by sample type, and by the location within the hospital from where the sample was obtained.

Respiratory syncytial virus infection in the early period after open-heart surgery in pediatric patients: impacts on the postoperative course and treatment outcome.

Objective To summzarize the impacts of respiratory syncytial virus (RSV) infection in the early period(< 72 h) on the postoperative course after open-heart surgery in pediatric patients, and to discuss the expe-riences on therapeutic strategies. Method From March 2005 to March 2008, 39 patients diagnosed to be RSV in-fection confmned by RSV antigen test were prospectively enrolled into RSV-infeetion group. Anoth.er 39 patients were randomly 1 : 1 matched with age and same type of congenital heart disease (CHD) during the same period who also underwent open-heart surgery without RSV infection (nonRSV-infection group) as control group. The medical records of these patients were retrospectivdy reviewed. The duration of mechanical ventilation (MV), length of ICU stay and hospital stay were compared between the two groups with Paired Student's t test. Meanwhile Fisher' s exact test was used to compare the differences in noninvasive positive pressure ventilation, incidence rate of re-intubafion and severe postoperative complications between groups. Patients in both groups were further divided into subgroups aceonting to differences in age, cyanosis and pulmonary arterial pressure in order to identify the dif-ferent impacts of RSV infection in patients in different settings. Results All the patients were survived and dis-charged home. RSV infection significantly prolonged the duration of MV, ICU and hospital stay (all P < 0. 05).In addition, it significantly increased the incidence of pulmonary atelectasis (P < 0.05). In patients under 6 months old, RSV infection resulted in prolongation of MV, ICU and hospital stay (all P <0.05); furthermore, it significantly increased the incidence of complications of low cardiac output syndrome and bacteria co-infection (both P = 0.05). In patients over 24 months, RSV infection had no significant impacts in all the parameters which are compared between the two groups. In patients with cyanotic CHD, RSV infection significantly prolonged the duration of MV, ICU stay and hospital stay (all P < 0.05). In patients with cyanotic CHD, RSV infection significantly prolonged the duration of ICU stay and hospital stay (P <0.05). In patients with pulmonary hyper-tension, RSV infection significantly prolonged the duration of MV, ICU and hospital stay(all P <0.05), and in-creased the incidence rate of concomitant infection (P < 0.05). However, in patients without pulmonary hyper-tension, RSV infection only significantly increased the length of hospital stay (P < 0.05). Conclusions RSV in-fection in the early period after open-heart surgery in pediatric patients has significant adverse impacts on the post-operative course, especially in those patients under 6 months old, patients with pumonary hypertension or cyanotic CHD. Early diagnosis, and effective circulatory and respiratory support,alone with antivirus results in a satisfied outcome. Key words: Congenital heart defect; Respiratory syncytial virus; Complications; Pediatrics; Infection

Prevalence of Bordetella pertussis and Bordetella parapertussis in Infants Presenting to the Emergency Department with Bronchiolitis

The clinical presentation of Bordetella pertussis can overlap with that of respiratory syncytial virus (RSV), and coinfection does occur, but management differs. The prevalence of B. pertussis is < 2% among Emergency Department (ED) patients with bronchiolitis. Our secondary hypothesis was that the prevalence of Bordetella parapertussis is also < 2% among these patients. Nasal washings were obtained from children up to 18 months of age (inclusive) who presented to a county hospital ED with a clinical diagnosis of bronchiolitis. These washings were frozen to -70°C before testing for B. pertussis and B. parapertussis using species-specific real-time polymerase chain reaction (PCR) assays. The assays were optimized to target conserved regions within a complement gene and the CarB gene, respectively. A Bordetella spp. genus-specific real-time PCR assay was designed to detect the Bhur gene of B. pertussis, B. parapertussis, and B. bronchiseptica. RSV antigen detection was also performed. There were 227 patients enrolled. After exclusions, 204 remained in the analysis. RSV antigen testing was positive in 109/186 (59%) of the patients in whom it was performed. All samples were tested for B. pertussis. B. parapertussis testing could not be completed on 23 samples. No cases (0/204; 95% confidence interval [CI] 0-1.8%) tested positive for B. pertussis or B. parapertussis (0/181; 95% CI 0-2%). The prevalence of B. pertussis in children presenting to the ED with bronchiolitis was < 2%.

Urinary tract infection must be excluded in febrile infants less than 3 months of age with positive respiratory syncytial virus antigen test

Study objectives: The prevalence of significant bacterial infections in young infants who have respiratory syncytial virus (RSV) is unknown in the era after the introduction of <i>Haemophilus influenzae</i> and <i>Streptococcus pneumoniae</i> vaccinations. The evaluation of these infants remains controversial. We hypothesize that infants with fever and RSV are at low risk for secondary bacterial infection and may not require extensive and invasive laboratory evaluations. Methods: This was a prospective evaluation; all infants younger than 3 months from October 1998 to December 2003 who had a sepsis evaluation for fever and an RSV antigen test performed were eligible. Infants excluded were those with previous antibiotic use and immunosuppression. Results: There were 128 infants in the study; 50 (39%) were RSV positive, and 78 (61%) infants were RSV negative. Median age in the RSV-positive group was 44.3±19.4 days and in the RSV-negative group, 43.6±19.2 days. In the RSV-positive group, there were 30 (60%) boys, 11 (22%) whites, 29 (58%) blacks, and 10 (20%) Hispanics. In the RSV-negative group, there were 42 (53.8%) boys, 12 (15.3%) whites, 54 (69.2%) blacks, and 10 (12.8%) Hispanics. In the RSV-positive group, median temperature was 38.6±0.6°C, whereas in the RSV-negative group it was 38.5±0.5°C. In the RSV-positive group, mean pulse rate was 170.7±18.5 beats/min, with a pulse rate greater than 160 beats/min in 27 (54%) patients. In the RSV-negative group, mean pulse rate was 165.9±21.1 beats/min, with a pulse rate greater than 160 beats/min in 37 (47.4%) patients. In the RSV-positive group, mean respiratory rate was 48.2±18 breaths/min, with a respiratory rate greater than 60 breaths/min in 10 (20%) patients. In the RSV-negative group, mean respiratory rate was 44.2±15.9 breaths/min, with a respiratory rate greater than 60 breaths/min in 8 (10.2%) infants. There was no significant difference in vital signs between groups. There were more upper respiratory infection symptoms and coughing in the RSV-positive group (<i>P</i><.05). The number of patients admitted in the RSV-positive group was 38 (76%) versus 62 (79.4%) in the RSV-negative group. There were 6 (12%) infants admitted to the pediatric ICU in the RSV-positive group versus 1 (1.2%) in the RSV-negative group. The laboratory evaluation in the RSV-positive group included a CBC count of 46 (92%), urinalysis and culture 44 (88%), blood culture 45 (90%), chest radiograph 21 (62%), and CSF fluid analysis 22 (44%). In the RSV-negative group, the laboratory evaluation included a CBC count of 71 (91%), urinalysis and urine culture 71 (91%), blood culture 73 (93.5%), chest radiograph 36 (46.1%), and CSF fluid analysis 53 (67.9%). There were more chest radiographs performed in the RSV-positive group (<i>P</i><.05). There were 7 (14%) significant infections in the RSV-positive group versus 8 (10.2%) in the RSV-negative group. In the RSV-positive group, there were 5 (10%) instances of pneumonia and 1 (2%) instance of urinary tract infection (UTI). There were no significant positive blood culture results in the RSV-positive group, but there were 4 (8%) contaminant results. In the RSV-negative group, there were 4 (5.1%) instances of pneumonia, 3 (2.5%) of UTI, 1 (1.2%) of bacteremia with group B streptococcus, and 1 (1.2%) of meningitis with enterococcus. Conclusion: The risk of serious bacterial infection is low in the RSV-positive group, especially if one excludes pneumonias. There were no cases of bacteremia or meningitis; however, UTIs still are significant. Therefore, it may be prudent to exclude a UTI in febrile infants with a positive RSV antigen test. Further studies with greater numbers are needed to validate these results.

Influenza A in Young Children with Suspected Respiratory Syncytial Virus Infection

Objectives: To determine the prevalence of influenza A in young children suspected of having respiratory syncytial virus (RSV) infection and to compare the clinical presentation of these patients with those who have proven RSV infection. Methods: Children younger than or at 36 months of age who presented to a pediatric emergency department (ED) with suspected RSV infection during the influenza A season of 2001–2002 were eligible. Eligible children had an RSV antigen test ordered as part of their initial clinical management. A consecutive sample of children was enrolled for prospective observational analysis. The main outcome measure was the prevalence of influenza A in young children with suspected RSV infection. The secondary outcome measure was a comparison of the clinical presentations, of the two groups. Results: During the study period, 420 patients presented for evaluation of respiratory illness. RSV tests were ordered on 251 patients. Of 197 eligible patients, 124 (63%) tested positive for RSV and 33 (17%) for influenza A. Influenza A patients were more likely to have temperatures at or above 39°C than RSV patients (36% vs. 15%; p = 0.01). RSV patients were more tachypneic (54 vs. 43 breaths/minute; p &lt; 0.0001) and more often had wheezing (90% vs. 8%; p &lt; 0.0001). Twenty influenza patients (61%) were hospitalized. Conclusions: This study found a high prevalence of influenza A in young children suspected of having RSV infection. Clinicians should consider influenza A in young febrile children presenting with respiratory illnesses.

Prevalence of serious bacterial infections in febrile infants with respiratory syncytial virus infection.

Neonates with fever generally undergo a full, invasive septic evaluation to exclude serious bacterial infection (SBI). The risk of SBI in febrile older infants and children with documented respiratory syncytial virus (RSV) infection has been found to be negligible. The purpose of this study was to investigate the prevalence of SBI in febrile infants who were younger than 8 weeks and had documented RSV infection and to compare the risk of SBI with control subjects who were febrile and RSV-negative. This was a retrospective cohort study of infants who were age 8 weeks or less and presented with documented fever to the emergency department at an urban children's hospital in October through April during a 4-year period. RSV-positive cases were gender- and age-matched to febrile RSV-negative control subjects. Clinical characteristics and the rate of SBI were compared between the 2 groups. A total of 174 previously healthy infants with fever and a positive RSV antigen test were identified and matched with 174 previously healthy infants with fever and a negative RSV test. Infants with RSV infection were more likely to present with upper respiratory infection symptoms, increased work of breathing, and apnea. Overall, 2 patients in the RSV group had SBI (both with urinary tract infections), compared with 22 in the control group (relative risk: 0.009), 17 of which were urinary tract infections. The risk of SBI in febrile infants with RSV infection seems to be very low, particularly in comparison with a control group of RSV-negative infants. These data suggest that full septic evaluations are not necessary in nontoxic-appearing infants with a positive RSV test. It seems to be prudent to examine the urine in these infants, as there is a clinically relevant rate of urinary tract infection.