Prevalence Of Respiratory Syncytial Virus Research Articles

Prevalence of Respiratory Syncytial Virus Infection among Hospitalized Children Presenting with Acute Lower Respiratory Tract Infections

To evaluate the prevalence of RSV among hospitalized young children presenting with ALRI in Bangalore, India. Respiratory syncytial virus (RSV) antigen detection was performed by direct fluorescent antibody (DFA) staining on 77 nasopharyngeal wash samples collected from hospitalized children below 2 years of age with a diagnosis of acute lower respiratory tract infection (ALRI). Out of 77 samples tested for RSV with DFA, 17 (22.1%) were found RSV-positive with a mean age of 8.24 ± 7.21 months (M:F = 1.8:1). Three children had congenital cardiac disease and one child had a history of prematurity. One child had re-infection within one month of primary infection. RSV-infected children were more likely to have a diagnosis of bronchiolitis than RSV-negative children (p < 0.001). RSV infection is a significant cause of morbidity among children presenting with ALRI in southern India. In resource-limited settings, DFA can be used as an important tool for rapid detection of RSV and can potentially eliminate prolonged hospitalization and unnecessary use of antibiotics.

Etiology survey on virus of acute respiratory infection in Guangzhou from 2006 to 2009

To investigate the pathogens of acute respiratory infection (ARI) in Guangzhou from 2006 to 2009. A total of 1554 cases of ARI patients in Second Affiliated Hospital of Guangzhou Medical College from September 2006 to September 2009, were recruited in the survey. The sample of throat and pharyngeal swab were collected from each patient.11 types of virus including influenza A (FluA), influenza B (FluB), adenovirus (ADV), human rhinovirus (HRV), respiratory syncytial virus (RSV), parainfluenza virus type 1, type 2, type 3 (HPIV1, HPIV2, HPIV3), human metapneumovirus (MPV) and human coronavirus (HCoV) type 229E, type OC43 were detected by Fluorescence Quota PCR method. The epidemic feature and clinical characteristic of each virus were then analyzed. Virus were found in 1024 samples in total, accounting for 65.9% (1024/1554). RSV was the most common virus, which was found in 261 samples (16.8%); and followed by HRV as 13.9% (216/1554), FluA as 11.6% (181/1554), MPV as 6.5% (101/1554), FluB as 6.4% (99/1554), HPIV as 4.9% (76/1554), ADV as 3.5% (55/1554) and HCoV as 2.3% (35/1554). HPIV and HCoV shared a similar infection ratio among different age groups. The infection ratio of FluA and FluB was highest among 15-24 years old group, accounting for 16.5% (29/176) and 7.4% (13/176) respectively. MPV, RSV and HRV were the main pathogens caused infection among children under 4 years old, accounting for 9.7% (49/503), 21.7% (109/503) and 18.9% (95/503). The infection ratio of ADV was 6.0% (19/318), which was the most common pathogen among 5-14 years old patients. The incidence rate of HPIV and HRV showed no obvious seasonal features; while the prevalence of FluA, FluB, RSV, ADV, MPV and HCoV changed significantly in different seasons.22.2% (227/1024) ARI patients co-infected other respiratory virus.90.1% (163/181) FluA patients, 88.9% (88/99) FluB patients and 92.7% (51/55) ADV patients had high fever symptoms. RSV was the main pathogen of ARI, and the new-found virus MPV was also another crucial pathogen. Some pathogens' incidence rate were related to the season and patient's age. Co-infections of other respiratory virus were also detected in parts of ARI patients.

Prevalence of Respiratory Syncytial Virus (RSV) Risk Factors and Cost Implications of Immunoprophylaxis to Infants 32 to 35 Weeks Gestation for Health Plans in the United States

Background During the period of this study, the American Academy of Pediatrics (AAP) 2006 guidelines recommended respiratory syncytial virus (RSV) prophylaxis for infants 32 to 35 weeks gestation age (wGA) with two or more of five risk factors (RFs). New recommendations have recently been published in 2009. The cost implications of expanding this list of RFs to include other evidence-based RFs like passive smoke exposure (PSE), crowded living conditions (CLCs), and young chronological age (YCA) are unclear. Methods We estimated the prevalence of RSV RFs in a US sample of infants 32 to 35 wGA referred for prophylaxis from nine specialty pharmacy providers during the 2007–2008 season. We estimated the percent eligible for RSV prophylaxis under various potential RF coverage policies. Using a budget impact model, we calculated the per-member-per-month (PMPM) cost for each policy in 2007 USD for a hypothetical one million member plan. Results Infants 32 to 35 wGA represented 0.08% of the plan. Approximately 20.2% of these infants met at least two or more of five AAP RFs. Expanding this list to include one additional RF of PSE, CLC, or YCA increased the percent of infants potentially prophylaxed to 29.9%, 23.9%, and 47%, respectively. Adding all three RFs to the list (two or more of eight) increased the percent of infants potentially prophylaxed to 55.6%, and increased payer costs by 9 cents PMPM. Conclusion Expanding the AAP RF criteria to include PSE, CLC, and YCA would identify more 32 to 35 wGA infants at high risk for severe RSV disease at an acceptable budget impact.

Incidence and Severity of Respiratory Syncytial Virus Pneumonia in Rural Kenyan Children Identified through Hospital Surveillance

Although necessary for developing a rationale for vaccination, the burden of severe respiratory syncytial virus (RSV) disease in children in resource-poor settings remains poorly defined. We conducted prospective surveillance of severe and very severe pneumonia in children aged <5 years admitted from 2002 through 2007 to Kilifi district hospital in coastal Kenya. Nasal specimens were screened for RSV antigen by immunofluorescence. Incidence rates were estimated for the well-defined population. Of 25,149 hospital admissions, 7359 patients (29%) had severe or very severe pneumonia, of whom 6026 (82%) were enrolled. RSV prevalence was 15% (20% among infants) and 27% during epidemics (32% among infants). The proportion of case patients aged 3 months was 65%, and the proportion aged 6 months was 43%. Average annual hospitalization rates were 293 hospitalizations per 100,000 children aged <5 years (95% confidence interval, 271-371 hospitalizations per 100,000 children aged <5 years) and 1107 hospitalizations per 100,000 infants (95% confidence interval, 1012-1211 hospitalizations per 100,000 infants). Hospital admission rates were double in the region close to the hospital. Few patients with RSV infection had life-threatening clinical features or concurrent serious illnesses, and the associated mortality was 2.2%. In this low-income setting, rates of hospital admission with RSV-associated pneumonia are substantial; they are comparable to estimates from the United States but considerably underestimate the burden in the full community. An effective vaccine for children aged >2 months (outside the age group of poor responders) could prevent a large portion of RSV disease. Severity data suggest that the justification for RSV vaccination will be based on the prevention of morbidity, not mortality.

Viral pathogens in acute exacerbations of chronic obstructive pulmonary disease

The objective of this study is to determine the prevalence of respiratory syncytial virus (RSV) and other viral respiratory pathogens in emergency department (ED) patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD). COPD patients presenting to the ED with <10 days of AECOPD symptoms were eligible. We used PCR to test nasal swabs for common viral respiratory pathogens. We completed viral studies on 76 patients from two EDs. Patients had a mean age of 72 years, and were 68% male, 99% white, and 29% current smokers. Influenza vaccination was reported by 87%. Viruses were detected in 19 of 76 patients (25%). These included RSV A (2) and B (4); parainfluenza 1 (1), 2 (0), and 3 (2); influenza A (3) and B (0); rhinovirus (4); and human metapneumovirus (3). A putative viral etiology was identified in 25% of AECOPD presenting for emergency care, of which approximately one-third were RSV-related.

La fréquence du virus respiratoire syncytial et des autres virus respiratoires dans les hospitalisations de l’enfant: Une enquête de 3 ans

To assess the prevalence of respiratory syncytial virus (RSV) and other important respiratory viruses in children hospitalized in a pediatric hospital in Paris (France) during a 3-year period (2001 to 2004).The study included all patients aged 8 days to 16 years admitted from the community through emergency department with bronchiolitis, pneumonia, upper respiratory tract infection, asthma or acute isolated fever and who had nasopharyngeal samples taken for viral identification by immunofluorescence (RSV, influenza, para-influenza, and adenoviruses).A virus was found in 464 of 1208 patients with samples taken. RSV was identified in 375 patients, 74% of them younger than 6 months and diagnosed with bronchiolitis. RSV was isolated more often than any other virus, overall and for all diagnoses except "isolated fever," for which influenza was more frequent. In patients aged 24 months or older, influenza and RSV were identified at the same frequency. Overall, influenza virus was found in 53 patients, adenoviruses in 24 and para-influenza viruses in 11.RSV was the respiratory virus isolated most often, even in older children, during this 3-year study. The relative rarity of hospitalizations due to para-influenza viruses is characteristic of this area, compared with some other countries.

The use of imperfect diagnostic tests had an impact on prevalence estimation

Objective Problems arising with the estimation of sensitivity and specificity when two imperfect diagnostic tests are applied are widely discussed. Effects on the estimation of prevalence may be of importance as well. Different methods of dealing with two or more imperfect tests and unknown reference standard are contrasted with regard to their implications on prevalence estimation: discrepant analysis, composite reference standards, and latent class models. Study Design and Setting Prospective epidemiological multicenter study to determine the prevalence of respiratory syncytial virus in children with lower respiratory tract infections. A subsample of 1,003 patients from a hospital population and from a practice population is considered. Virus isolation, polymerase chain reaction, and rapid antigen test had been applied. Results Prevalence estimates obtained under various assumptions ranged from 0.263 to 0.386 in the hospital population and from 0.214 to 0.277 in the practice population. Conclusion Estimation procedures involving a resolver test applied to some but not all cells are at risk of introducing a serious bias in prevalence estimation as well as in the estimation of test accuracy parameters. Estimation via latent class modeling may be more useful, but care should be taken regarding the underlying assumptions.

Enhanced clinical utility of the NucliSens EasyQ RSV A+B Assay for rapid detection of respiratory syncytial virus in clinical samples

The aim of the present study was to compare traditional methods for the detection of respiratory syncytial virus with a newly developed commercial assay based on real-time nucleic acid sequence based amplification. Respiratory syncytial virus is a major cause of severe respiratory infection in infants and in certain groups of older children and adults. Treatment options are limited, but a rapid diagnosis improves patient management and infection control. The rapid diagnosis of respiratory syncytial virus currently relies on antigen detection assays. These tests are limited to use in certain good-quality types of samples, which are rarely obtained from adult patients. Molecular-based assays for the detection of respiratory syncytial virus are shown to be highly sensitive, specific, and more rapid than cell culture techniques. This retrospective study compared traditional laboratory techniques for the detection of respiratory syncytial virus in 508 respiratory samples collected during the winter months of 2003-2004 against the recently developed, commercially available NucliSens EasyQ Respiratory Syncytial Virus A+B assay (bioMérieux, Marcy l'Etoile, France), which is based on real-time nucleic acid sequence based amplification using molecular beacons and an internal control. Using traditional techniques, the prevalence of respiratory syncytial virus in the samples tested was found to be 21%. Using the real-time nucleic acid sequence-based amplification assay, an additional 41 samples from patients with a clinically diagnosed respiratory illness were found to be positive for respiratory syncytial virus. The NucliSens EasyQ assay was shown to be sensitive and specific for the detection of respiratory syncytial virus A+B in different types of respiratory samples. Moreover, the time required to complete the assay was <4 h, so results could be obtained on the same day as sample receipt in the laboratory.

Respiratory syncytial virus infection in children under one year of age hospitalized for acute respiratory diseases in Pelotas, RS

INTRODUCTION: Acute respiratory diseases (ARDs) are a major cause of infant morbidity and mortality. OBJECTIVE: The present case-controlled study investigated the hospitalizations by ARDs in children under one year of age and the association with the respiratory syncytial virus (RSV) in za Pelotas, RS. METHODS: All children under one year of age hospitalized due to ARDs from August 1997 to July of 1998 were followed-up in the four hospitals of the city. A standardized questionnaire was applied to the children's mother regarding symptoms of the actual illness in addition to social and demographic variables, nutrition, and previous morbidity. The final diagnosis of ARDs was performed by an arbiter (a pediatrician) based on the hospital records of the children and the data on the questionnaire. Nasopharyngeal secretions were collected for RSV detection by direct immunofluorescence. RESULTS: The study included 650 children and the annual incidence rate of hospital admissions for ARDs was 13.9%. Admissions showed a seasonal pattern with most of the hospitalizations occurring from July to October. The main causes of admission were: pneumonia (43.7%), bronchiolitis (31.0%), asthma (20.3%), influenza (3.5%), otitis media (0.8%) and laryngitis (0.6%). The overall prevalence of RSV was 30.7%, with 40.2% in bronchiolitis, 28.6% in influenza, 27.4% in asthma, 26.3% in pneumonia, and 25% in otitis media. CONCLUSIONS: The results of the present study confirm the high morbidity of ARDs in childhood and the seasonal pattern of ARDs hospitalizations and their association with RSV infection.

Prevalence of respiratory syncytial virus infection in Italian infants hospitalized for acute lower respiratory tract infections, and association between respiratory syncytial virus infection risk factors and disease severity.

This study was designed to collect data on the prevalence of respiratory syncytial virus (RSV) infection in Italy in infants hospitalized for lower respiratory tract infections, and to evaluate which of the recognized risk factors might be associated with disease severity. Thirty-two centers throughout Italy participated in the study. Over a 6-month period (November 1,1999 to April 30, 2000), we evaluated all children < 2 years of age hospitalized for lower respiratory tract infections. All subjects were tested for RSV within 24 hr of hospitalization by using an immuno-enzymatic diagnostic test (Abbott Testpack, RSV). Logistic regression was used to identify the factors that might be associated with more severe disease or could increase the likelihood of RSV positivity in hospitalized infants. Out of a total of 1,232 children enrolled, 40.6% were found to be RSV-positive (RSV+). The peak of the RSV epidemic occurred in February, while the lowest prevalence of RSV positivity was seen in November (P < 0.05). A high proportion of study subjects had low birth weight and low gestational age. The clinical diagnosis at hospitalization was bronchiolitis in 66.7%, pneumonia in 15.3%, and wheezy bronchitis in 18.1%. In the bronchiolitis group, a higher prevalence of RSV+ was found in patients with gestational age <or= 33 weeks or 34-35 weeks, as compared to those with a gestational age >or= 36 weeks (P < 0.04). No differences were found in the proportion of RSV+ patients in the three gestational age subgroups with pneumonia and wheezy bronchitis (P > 0.05, each comparison). Independent of the clinical diagnosis at admission, RSV infection was associated with more severe respiratory impairment. Environmental smoke exposure was higher in subjects with bronchiolitis than in those with wheezy bronchitis (P < 0.04), and RSV+ was positively related with the birth order (P < 0.05). The presence of older siblings and birth order plays an important role in RSV infection. The collected data show that, in Italy, RSV is an important cause of lower respiratory tract infection in infants. Gestational age, birth order, birth weight, and exposure to tobacco smoke affected the prevalence and severity of RSV-related lower respiratory tract disease.

Respiratory syncytial virus infections in malnourished children.

The prevalence of respiratory syncytial virus (RSV) infection among severely malnourished children was studied at the University of Benin Teaching Hospital, Benin City, Nigeria at a time when the infection was known to be prevalent in the community. Nasopharyngeal washings were obtained from subjects on admission and thereafter every 4 days until discharge. RSV was detected by ELISA technique. Of 20 well nourished children who served as controls, 11 were ELISA-positive for RSV (55%). Eight (16%) of the 51 patients who were malnourished were ELISA-positive, four of whom (8%) had nosocomial infection. Fever and rhinitis were the most common presenting features in the RSV-infected malnourished children. None of the children showed any clinical or radiological signs of lower respiratory tract infection. Malnourished children appear not to be at increased risk of RSV infection, and those who contract the infection usually do not manifest severe disease.

Sero-epidemiological studies of respiratory syncytial and adenoviruses in children in Ibadan, Nigeria, 1985–1988

Retrospective and prospective serological surveys to determine the prevalence of respiratory syncytial virus (RSV) and adenovirus (ADV) infections in children with respiratory diseases were carried out from 1985 to 1988 at the University College Hospital, Ibadan, Nigeria. 306 sera from subjects between 3 months and 12 years old were assayed by complement fixation test for antibodies to both viruses. Second samples were available from 42 of the subjects for antibody conversion testing. The rate varied with age, period of the year and virus. Overall prevalences of 23·5% and 18·3% were obtained for RSV and ADV respectively. 2·6% of the subjects had antibodies to both viruses. Among 42 paired samples tested, 61·9% and 33·3% showed positive antibody conversion to RSV and ADV respectively. Although there was evidence of active circulation of both viruses throughout the year, infection with RSV was higher from September to January, while ADV infection was significantly higher during February and March. Antibody prevalence to both viruses increased with age up to a peak of 39·1% for RSV in children 5–6 years old and 32% for ADV in children 3–4 years old. None of the subjects aged 10 years and above was positive for both viruses. Both RSV and ADV are important agents of acute respiratory infection in children in Nigeria.

Respiratory syncytial virus infections in SR Croatia, Yugoslavia.

The prevalence of respiratory syncytial virus (RSV) infection was studied during three consecutive annual outbreaks (1983-1986) in SR Croatia, Yugoslavia. A total of 1,238 subjects were examined, using RSV isolation and immunofluorescent (DTFA) methods, with 1,042 showing the signs of respiratory infection and 207 of these having a positive RSV finding. Generally, the prevalence of mild upper respiratory infection (URTI) was 18%, reaching a peak of 30% at 1 year of age. The prevalence of severe lower respiratory tract infections with bronchiolitis, pneumonia, and croup accounted for 51, 34.4, and 28.3% respectively. The highest incidence of RSV infection among respiratory cases was observed in the first 6 months of life (49.4%), being particularly high at the second month among those with URTI, bronchiolitis, pneumonia, and croup (76.2%). Both sexes were equally susceptible to RSV infection (20.51% females, 19.03% males). RSV infections, seasonal incidence ranged from 25.55 to 30.31% in 1983/84 and 1984/85 respectively and dropped sharply to 8.93% in 1985/86.