[Rhinovirus and acute respiratory infections in hospitalized children. Retrospective study 1998-2000]

Viral Bronchiolo-Alveolitis From Coronavirus OC43 and Rhinovirus-Simulating SARS-CoV-2 Infection

Viruses are the most common cause of acute lower respiratory tract. The respiratory syncytial virus infection is most commonly associated with viral bronchiolitis. Rhinovirus and coronavirus OC43 are less frequently responsible for lower respiratory tract infections. The virological spectrum has expanded greatly owing to the development of molecular biology techniques. We report the clinical case of a four-month-old infant who presented with acute lower respiratory infection with coronavirus OC43 (HCoV-OC43) and rhinovirus complicated by a particularly extensive spontaneous pneumomediastinum.

The Etiology of Childhood Pneumonia in Bangladesh: Findings From the Pneumonia Etiology Research for Child Health (PERCH) Study

BACKGROUND

Pneumonia remains the leading infectious cause of death among children <5 years, but its cause in most children is unknown. We estimated etiology for each child in 2 Bangladesh sites that represent rural and urban South Asian settings with moderate child mortality.

METHODS

As part of the Pneumonia Etiology Research for Child Health study, we enrolled children 1-59 months of age with World Health Organization-defined severe and very severe pneumonia, plus age-frequency-matched controls, in Matlab and Dhaka, Bangladesh. We applied microbiologic methods to nasopharyngeal/oropharyngeal swabs, blood, induced sputum, gastric and lung aspirates. Etiology was estimated using Bayesian methods that integrated case and control data and accounted for imperfect sensitivity and specificity of the measurements.

RESULTS

We enrolled 525 cases and 772 controls over 24 months. Of the cases, 9.1% had very severe pneumonia and 42.0% (N = 219) had infiltrates on chest radiograph. Three cases (1.5%) had positive blood cultures (2 Salmonella typhi, 1 Escherichia coli and Klebsiella pneumoniae). All 4 lung aspirates were negative. The etiology among chest radiograph-positive cases was predominantly viral [77.7%, 95% credible interval (CrI): 65.3-88.6], primarily respiratory syncytial virus (31.2%, 95% CrI: 24.7-39.3). Influenza virus had very low estimated etiology (0.6%, 95% CrI: 0.0-2.3). Mycobacterium tuberculosis (3.6%, 95% CrI: 0.5-11.0), Enterobacteriaceae (3.0%, 95% CrI: 0.5-10.0) and Streptococcus pneumoniae (1.8%, 95% CrI: 0.0-5.9) were the only nonviral pathogens in the top 10 etiologies.

CONCLUSIONS

Childhood severe and very severe pneumonia in young children in Bangladesh is predominantly viral, notably respiratory syncytial virus.

Virologic study of acute lower respiratory tract infections in children admitted to the paediatric department of Blida University Hospital, Algeria

Acute lower respiratory tract infections (ALRTI) such as pneumonia and bronchiolitis are major causes of mortality and morbidity in children under 5 years of age. The main microbial agents responsible for ALRTI are either bacterial agents (Streptococcus pneumoniae, Haemophilus influenzae type b, Mycoplasma pneumoniae) or viruses (respiratory syncytial virus (RSV, also known as human orthopneumovirus), Myxovirus influenzae, Myxovirus parainfluenzae, adenovirus) [1]. More recently, other viruses (rhinovirus, metapneumovirus, coronavirus, bocavirus) have been implicated in ALRTI; their identification has been facilitated by new molecular biology techniques such as real-time PCR. To our knowledge, these emerging viruses have never been the subject of epidemiologic studies in our country.

Prevalence of Human rhinovirus infection in young children with acute wheezing

Introduction

Recurrent wheezing is one of the leading causes of chronic illness in childhood. We aimed to evaluate the prevalence of Human Rhinovirus (HRV) infection in the acute attack of wheezy chest which began after a respiratory illness.

Methodology

The study was conducted on 200 children aged 2 months to 5 years presenting to the emergency department with an acute wheezy episode either for the first time or recurrent wheeze defined as >2 reports of wheezing in the first 3 years of life. All subjects were subjected to a complete history and clinical examination. Chest X-ray was done to all subjects. Nasopharyngeal and oropharyngeal swabs were obtained from all subjects and the presence of HRV was determined by PCR examination.

Results

By PCR method, 163 patients (81.5%) were positive for viral infection. Due to viral co-infection, 49.5% (99 cases) were +ve for Respiratory Syncytial virus followed by HRV 43.5% (87 cases).

Conclusion

HRV was the second common viral infection in children with wheezes. Its prevalence was more in winter with higher incidence of recurrence. Compared to the other respiratory viruses, it had the higher mortality 43.7%.

Evaluation of a novel real-time RT-PCR using TOCE technology compared with culture and Seeplex RV15 for simultaneous detection of respiratory viruses

Background

Various kinds of commercial molecular systems have been developed for fast and more accurate detection of respiratory viruses. Anyplex™ II RV16 [RV16] was designed for simultaneous detection of 16 respiratory viruses using multiplex PCR coupled with TOCE™ technology.

Objectives

To compare the performance of RV16 with those of culture and Seeplex^® RV15 ACE [RV15] by determining their sensitivity and specificity.

Study design

Seven hundred and thirty respiratory samples were tested by modified shell vial culture method, RV16, and RV15. For molecular tests, automated nucleic acid extraction and liquid handling system using MICROLAB Nimbus IVD (Hamilton, USA) was adopted to maximize the workflow and accuracy. Performance of each assay was determined against a composite reference standard.

Results

Two hundred and one samples (28%) out of 730 samples were positive by culture, while additional 281 (39%) were positive by RV16 or RV15. Sensitivities of RV16, RV15, and culture for virus tested were as follows: 100/93/63% for influenza A, 90/80/69% for influenza B, 98/94/63% for RSV, 98/52/23% for adenovirus, and 100/75/46% for PIV. For viruses not covered by culture, sensitivities of RV16 and RV15 were as follows: 99/81% for rhinovirus, 92/100% for coronavirus OC43, 100/56% for coronavirus 229E/NL63, 92/88% for metapneumovirus, 100/62% for bocavirus, and 91/91% for enterovirus. Overall, the specificities of culture, RV16, and RV15 (Seegene) were 100/99.9/99.9%.

Conclusions

RV16 assay was superior to culture method and RV15 and will be a promising tool for patient management and public health epidemiology.

Virological and clinical characterizations of respiratory infections in hospitalized children

BACKGROUND

The purpose of this study was to determine the incidence and seasonal distribution of viral etiological agents and to compare their clinical manifestations and disease severity, including single and co infections.

METHODS

Multiplex reverse-transcription PCR was performed for the detection of viruses in nasopharyngeal aspirat. Disease severity was grouped using a categorization index as very mild/mild, and moderate/severe. Clinical and laboratory characteristics of hospitalized children with viral respiratory tract infection were analyzed.

RESULTS

Viral pathogens were detected in 103/155 (66.5%) of patients. In order of frequency, identified pathogens were respiratory syncytial virus (32.0%), adenovirus (26.2%), parainfluenza viruses type 1-4 (19.4%), rhinovirus (18.4%), influenza A and B (12.6%), human metapneumovirus (12.6%), coronavirus (2.9%), and bocavirus (0.9%). Coinfections were present in 21 samples. Most of the children had very mild (38.8%) and mild disease (37.9%). Severity of illness was not worse with coinfections. The most common discharge diagnoses were "URTI" with or without LRTI/asthma (n=58). Most viruses exhibited strong seasonal patterns. Leukocytosis (22.2%) and neutrophilia (36.6%) were most commonly detected in patients with adenovirus and rhinovirus (p<0.05). Monocytosis was the most remarkable finding in the patients (n=48, 53.3%), especially in patients with adenovirus (p<0.05).

CONCLUSIONS

RSV and RhV were associated with higher severity of illness in hospitalized children. RSV found to account for half of LRTI hospitalizations. In AdV and FluA and B infections, fever lasted longer than in other viruses. Coinfections were detected in 21 of the patients. The presence of coinfections was not associated with increased disease severity.

A retrospective analysis of nosocomial viral gastrointestinal and respiratory tract infections

BACKGROUND

Viral nosocomial infections (NIs) in children are common and most frequently affect the gastrointestinal or respiratory tract. Few studies are dedicated to this topic. We aimed to determine incidence and characteristics of these specific viral NIs at our hospital.

METHODS

This was a retrospective analysis of nosocomial gastroenteritis and respiratory tract infections (RTIs) of hospitalized patients at the University Children's Hospital Basel over a 12-month period. Patients with new-onset gastroenteritis or RTI during hospitalization or a physician diagnosis of NI on discharge were included for analysis. NIs were defined by use of Centers for Disease Control and Prevention recommendations and specific agents' incubation periods.

RESULTS

Overall, 5493 patients were hospitalized accounting for 22,251 hospital days. Forty-five (0.8%) patients acquired an NI: 15 cases of gastroenteritis (mean age, 9.9 months; range: 3-24; NI incidence: 0.7 per 1000 hospitalization days) and 30 cases of RTI (mean age, 63.7 months; range: 1-174; NI incidence: 1.3 per 1000 hospitalization days). Main agents were rotavirus (10/15 gastroenteritis, 67%) and rhinovirus (22/30 nosocomial RTI; 73%). Physicians reported 9 cases of NI, of which 2 (22%) did not fulfill the criteria for an NI, 3 were surgical site infections, 1 was a case of rotavirus gastroenteritis and 3 were RTIs by rhinovirus.

CONCLUSIONS

Viral NIs, especially caused by rotavirus and rhinovirus, are frequent in children of all ages but underestimated if exclusively reported by physicians. Prospective studies should further investigate the role and epidemiology of rhinovirus in nosocomial RTI, ideally by use of automated information technology support.

Comparison of two broadly multiplexed PCR systems for viral detection in clinical respiratory tract specimens from immunocompromised children

Background

The detection of viral respiratory tract infections has evolved greatly with the development of PCR based commercial systems capable of simultaneously detecting a wide variety of pathogens.

Objectives

Evaluate the relative performance of two commercial broad range systems for the detection of viral agents in clinical respiratory tract specimens from immunocompromised children.

Study design

A total of 176 patient samples were included in the analysis, representing only the first sample collected for each patient, and excluding failed reactions. Samples were de-identified and assayed in parallel using two different, broadly multiplexed PCR systems: ResPlex™ II Panel v2.0 (ResPlex), Qiagen, Hilden, Germany and FilmArray^® Respiratory Panel (FilmArray), Idaho Technology Inc., Salt Lake City, UT. Method comparison was based upon pair-wise concordance of results according to patient age, viral target and number of targets detected.

Results

The two systems showed an overall concordance, by patient, of 83.8% (p = 0.0001). FilmArray detected at least one target in 68.8% of samples, while ResPlex detected at least one target in 56.8%. ResPlex failed to detect 20.7% of FilmArray positives, and FilmArray failed to detect 4% of ResPlex positives. The relative performance of each system (including which system detected a higher number of positive samples) varied when stratified by target viral pathogen.

Conclusions

Broadly multiplexed PCR is an effective means of detecting large numbers of clinically relevant respiratory viral pathogens.

Clinical evaluation of multiplex real-time PCR panels for rapid detection of respiratory viral infections

Respiratory viral infections are one of the leading causes of morbidity and mortality, particularly in children, the elderly and immunocompromised persons. Rapid identification of viral etiology is critical in ruling out non‐viral infections, initiating antiviral treatment and limiting the spread of the infection. Multiplex assays of more than one viral gene target in a single tube have the advantage of rapid screening of a large number of potential viral pathogens in a short time. A multiplex real‐time PCR assay was used in this study for detection of respiratory RNA and DNA viral infections in 728 specimens received from 585 adult and pediatric patients comprised of symptomatic and asymptomatic organ transplant recipients and non‐recipients for diagnosis of respiratory illnesses and for routine clinical monitoring. Multiplex PCR was more sensitive than the multiplex immunofluoresence culture assay (R‐mix) and also detected additional respiratory viruses that were not covered by the R‐mix panel. The number of respiratory viruses detected in symptomatic patients was significantly higher than asymptomatic patients in both adult and pediatric patients. Herpesviral infections were the predominant cause of lower respiratory tract infection in the organ transplant recipients, whereas respiratory syncytial virus was the most common pathogen in non‐transplant patients particularly children. Multiplex real‐time PCR for detection of respiratory viruses has the potential for rapid identification of viral pathogens. In this era of emerging viral infections, addition of newer viral targets to the multiplex PCR panels will be beneficial in determining both patient management and public health epidemiology. J. Med. Virol. 84:162–169, 2011. © 2011 Wiley Periodicals, Inc.

Bronconeumopatías agudas del niño

Las infecciones infantiles afectan con frecuencia al aparato respiratorio inferior. Las clasificaciones convencionales, basadas en el tipo de afección anatómica, radiológica y etiopatogénica, permiten definir entidades clínicas (bronquitis, bronquiolitis, neumopatía); sin embargo, la evaluación de la gravedad del proceso es lo más útil para decidir el tipo y la rapidez del tratamiento. Aunque la etiología viral es la más frecuente, la estrategia fundamental para reducir la morbilidad e incluso la mortalidad de las infecciones respiratorias bajas se basa en el tratamiento adecuado de las neumonías bacterianas. Ante la ausencia de especificidad, es indispensable, cuando esté indicado, recurrir a una antibioticoterapia inicial probabilística que incluya el neumococo. En el niño, las muestras no suelen proceder del parénquima pulmonar y, además, la recogida de las secreciones bronquiales durante los primeros años de vida no es de buena calidad. Al contrario de lo que ocurre con los virus, el examen bacteriológico de las secreciones de las vías respiratorias altas es poco útil, porque los niños suelen ser portadores de gérmenes que pueden causar neumopatías. Los datos clínicos y radiológicos sólo pueden sugerir el diagnóstico. El desarrollo de técnicas que detectan antígenos microbianos o la búsqueda de material genético por biología molecular han permitido mejorar de manera significativa la identificación del patógeno responsable y la elección del tratamiento adecuado. Algunos grupos particulares de pacientes pueden padecer una afección respiratoria por agentes infecciosos inusuales o, incluso, oportunistas. Una proporción importante de la afectación respiratoria del adulto puede atribuirse a las agresiones pulmonares sufridas durante su infancia. La aplicación de vacunas, en especial, la antigripal y la antineumocócica, es fundamental para la prevención de estas afecciones respiratorias.

The Transition from Bronchopulmonary Dysplasia to Childhood Chronic Lung Disease

The impact of a preterm birth on lung function in later life is not always predictable and the variability of lung phenotype in these children can be striking even among children of the same gestational age. Although many children with a history of bronchopulmonary dysplasia (BPD) improve with age, others continue to manifest significant pulmonary abnormalities. Several different lung phenotypes have been described in older children with a history of BPD. These descriptions have been based in part on chronic respiratory symptoms, pulmonary function abnormalities, and response to respiratory illnesses. These lung phenotypes include large and/or small airway dysfunction, impaired alveolar growth characterized by decreased pulmonary reserve, and pulmonary hypertension found primarily in children with severe chronic lung disease. Children with a history of BPD can manifest 1 or more of these lung phenotypes with varying degrees of severity. Currently, treatment of respiratory symptoms is primarily supportive and symptom based. Although many children improve with age, others continue to have chronic respiratory symptoms into adult life. The development of standardized guidelines for the care of children after discharge from the neonatal intensive care unit may help direct appropriate therapy, limit lung injury, and maximize lung growth potential in this vulnerable group of children.

[Bronchiolitis viruses]

In Normandy (France), human respiratory syncytial virus (hRSV) was detected in 64.1% of acute bronchiolitis in hospitalized children, rhinovirus in 26.8%, human metapneumovirus (hMPV) in 7.6%, and parainfluenza virus (PIV) in 3.4%. The viruses causing acute bronchiolitis in the community were hRSV (42%), rhinovirus (19.5%), coronavirus (8%), PIV (3.5%), and hMPV (2.5%). In 53.7% of the cases, hRSV infected infants (86.9%), 53.7% being less than 6 months of age. Of the hRSV cases, 48.2% were detected in November and December and 44.5% in January and February. The hRSV epidemic started the 1st or 2nd week of October but it varied from one year to another and from one region to another. hRSV acute bronchiolitis increased from 261 cases in epidemics from 1999-2003 to 341 cases from 2004-2009. Rhinoviruses gave acute bronchiolitis in 38.4% of cases. A rate of 54.6% of viruses was detected in September and October and 38.5% in March and April. A total of 34.2% of infected infants were under 6 months of age, 37.8% between 6 months and 2 years, and 19.5% were between 2 and 5 years old. hMPV epidemics coincided with hRSV epidemics, but they accounted for one-sixth the number of cases. HMPV infected infants (74%) who were older than those infected with hRSV, and the diagnosis was bronchiolitis (59%) and pneumonia (17%). PIV infections (about 100 cases per year) included PIV3 (62.7%), PIV1 (25.3%), and PIV2 (7.3%). PIV1 infections occurred every 2 years in the fall. PIV3 infections were observed every year during the fall and winter, with peaks of infections in the spring in the years without PIV1. There were acute cases of bronchiolitis in 29.8% of PIV3 infections and 18.3% in PIV1 infections.

Viral respiratory infections in hospitalized and community control children in Alaska

Respiratory syncytial virus (RSV) in Alaska Native children from the Yukon Kuskokwim (YK) Delta is associated with a hospitalization rate five times higher than that reported for the general US child population. The role of other viral respiratory pathogens has not been studied in this population. YK Delta children <3 years of age hospitalized with respiratory infections and same aged community control children were prospectively enrolled between October 2005 and September 2007. Polymerase chain reaction detection of viruses was performed on nasopharyngeal samples. Characteristics of hospitalized and asymptomatic control children were analyzed. From October 2005 to September 2007, 440 hospitalized and 425 control children were analyzed. Respiratory viruses were detected in 90% (395) of hospitalized children: 194 (44%) rhinovirus, 131 (30%) adenovirus, 102 (23%) RSV, 77 (18%) para influenza viruses (PIV), 66 (15%) human metapneumovirus (hMPV), 23 (5%) influenza, and 25 (6%) coronavirus. Fifty-two percent (221) of control children had a virus detected, most commonly rhinovirus (33%), and adenovirus (16%). RSV, PIV, hMPV, and influenza were significantly more common in hospitalized cases than control children, but rhinovirus, adenovirus, and coronavirus were not. RSV and hMPV were associated with higher severity of illness. In this study, RSV remains the most important virus associated with respiratory hospitalization, although hMPV and PIV were also common. RSV and hMPV were associated with more severe illness. Rhinovirus and adenovirus were detected in two-thirds of hospitalized children, but their frequent detection in control children made their role in respiratory hospitalization uncertain.

Prevalence of human metapneumovirus among hospitalized children younger than 1 year in Catalonia, Spain

Human metapneumovirus was discovered recently respiratory virus implicated in both upper and lower respiratory tract infection. In children, the clinical symptoms of human metapneumovirus are similar to those produced by respiratory syncytial virus, ranging from mild to severe diseases such as bronchiolitis and pneumonia. The aim of the present study was to describe the prevalence of human metapneumovirus and other common respiratory viruses among admitted to hospital infants. From January 2006 to June 2006, 99 nasopharyngeal aspirates were collected from hospitalized children younger than 12 months in order to study respiratory viruses. Human metapneumovirus detection was performed by cell culture and two RT‐PCR targeting on polymerase and fusion genes. The latter gene was used for phylogenetic analysis. In 67/99 children (67%) at least one viral pathogen was identified, the viruses detected most frequently were respiratory syncytial virus (35%), human metapneumovirus (25%) and rhinovirus (19%). The results obtained in this study, show that: (1) human metapneumovirus is one of the most important viruses among children less than 12 months; (2) children infected with human metapneumovirus were significantly older than those infected by respiratory syncytial virus; (3) human metapneumovirus was associated more frequently with pneumonia whereas respiratory syncytial virus was only detected in patients with bronchiolitis; (4) there was a clear epidemiological succession pattern with only a small overlap among the viruses detected most frequently; (5) all human metapneumovirus samples were clustered within sublineage A2. J. Med. Virol. 80:1452–1460, 2008. © 2008 Wiley‐Liss, Inc.

Study of influenza C virus infection in France

From November 2004 to April 2007, specimens were obtained from 2,281 patients with acute respiratory tract illness in Normandy, France. Eighteen strains of influenza C virus were detected in these samples using a combined tissue culture/RT-PCR diagnostic method. Most patients with influenza C virus infection (13/18) were infants or young children (<2 years of age). The most frequent symptoms were fever and cough, and the clinical presentation of influenza C virus infection was similar to that of other respiratory viruses. Thirteen of the 18 infected patients were hospitalized; 3 presented with a severe lower respiratory infection. The hemagglutinin-esterase (HE) gene of 10 isolates was sequenced to determine the lineages of the circulating influenza C viruses. Phylogenetic analysis revealed that most of the isolated strains had an HE gene belonging to the C/Yamagata/26/81-related lineage. These results show that influenza C virus regularly circulates in Normandy and generally causes a mild upper respiratory infection. Because the differential clinical diagnosis of influenza C virus infection is not always easy, it is important to identify viral strains for both patient management and epidemiological purposes.

Rhinovirus infection in hospitalized children in Hong Kong: a prospective study

OBJECTIVES

To analyze the clinical features and estimate the hospitalization disease burden of rhinovirus infection in children in Hong Kong.

METHODS

In this prospective study, nasopharyngeal aspirates were taken from children aged <18 years with symptoms of acute respiratory infection admitted to Queen Mary Hospital on one fixed day of the week during August 2001-July 2002 for detection of common respiratory viruses by immunofluorescence, viral culture, and for rhinovirus, human metapneumovirus, and coronaviruses by reverse transcription polymerase chain reaction. The clinical features of rhinovirus infections were analyzed and hospitalization disease burden was estimated.

RESULTS

Altogether 239 of the 426 nasopharyngeal aspirates (56.1%) were positive for respiratory viruses, including 151 patients with rhinovirus (35.4%). The median age was 2.34 years. Upper respiratory infection, asthma exacerbation, pneumonia, and acute bronchiolitis were diagnosed in 44.4%, 19.9%, 11.3%, and 7.9%, respectively. The most common symptoms were cough (81.5%), runny nose (76.8%), and fever (68.9%). Shortness of breath, wheezes, and crepitation were present in 25.8%, 29.1%, and 18.5%, respectively. Fifty-five of 99 patients (55.6%) had chest radiographic abnormalities, most commonly perihilar streakiness. Children with chronic diseases were more likely to have lower respiratory tract infection and these children required longer hospitalization (mean 0.6 days longer). Coinfection with other respiratory pathogens was common (33.1%).

CONCLUSION

Rhinovirus is frequently associated with asthmatic exacerbations and lower respiratory tract infection, especially in children with chronic diseases and is potentially an important contributor to hospitalization in children in Hong Kong.

Currently used nucleic acid amplification tests for the detection of viruses and atypicals in acute respiratory infections

For the detection of respiratory viruses conventional culture techniques are still considered as the gold standard. However, results are mostly available too late to have an impact on patient management. The latest developments include appropriate DNA- and RNA-based amplification techniques (both NASBA and PCR) for the detection of an extended number of agents responsible for LRTI. Real time amplification, the latest technical progress, produces, within a considerable shorter time, results with a lower risk of false positives. As results can be obtained within the same day, patient management with appropriate therapy or reduction of unnecessary antibiotic therapy in LRTI will be possible. A number of technical aspects of these amplification assays, and their advantages are discussed.

The availability and use of these new diagnostic tools in virology has contributed to a better understanding of the role of respiratory viruses in LRTI. The increasing importance of the viral agents, Mycoplasma pneumoniae and Chlamydophila pneumoniae in ARI is illustrated. A great proportion of ARI are caused by viruses, but their relative importance depends on the spectrum of agents covered by the diagnostic techniques and on the populations studied, the geographical location and the season. The discovery of new viruses is ongoing; examples are the hMPV and the increasing number of coronaviruses. Indications for the use of these rapid techniques in different clinical situations are discussed. Depending on the possibilities, the laboratory could optimize its diagnostic strategy by applying a combination of immunofluorescence for the detection of RSV an IFL, and a combination of real-time amplification tests for other respiratory viruses and the atypical agents. When implementing a strategy, a compromise between sensitivity, clinical utility, turn around time and cost will have to be found.

Comparison of multiplex PCR assays and conventional techniques for the diagnostic of respiratory virus infections in children admitted to hospital with an acute respiratory illness

The performances of four multiplex PCR (m‐PCR) were compared to direct immunofluorescence assay (DFA) and HuH7 cell culture for the detection of viruses in 263 children admitted to hospital with an acute respiratory illness. One hundred fifty (57.6%) nasal aspirates were found DFA‐positive; 188 (72.3%) were found positive by both DFA and HuH7 cell culture, and 242 (92%) were PCR‐positive. The m‐PCR detected 124 viruses which were not found by conventional methods: 68 rhinovirus, 17 human metapneumovirus, 15 respiratory syncytial virus (RSV), 8 parainfluenza virus (PIV), 5 coronavirus 229E, 3 OC43 and 3 NL63, 4 enterovirus, 2 influenza virus B and C virus. The m‐PCR were more sensitive, had the advantages of a shorter delay in specific diagnosis, and a lower cost than DFA and culture. Using these m‐PCR, the prevalence of each virus was compared between in‐patient and out‐patient groups of children attending the emergency unit of the hospital. Nasal aspirates from 411 (91.5%) children were found positive by the PCRs. RSV, rhinovirus, and influenza virus were the most frequent viruses detected in this population, representing 43.6%, 31.8%, and 8.8% of the virus found, respectively, followed by human metapneumovirus (4.4%), coronavirus (3.4%), parainfluenza virus (3.2%), adenovirus (2.3%), and enterovirus (2.1%). RSVs were detected more significantly in the in‐patient group than in the out‐patient group, and influenza viruses were detected more frequently in the out‐patient group than in the in‐patient group. Moreover, the use of m‐PCR pointed out the frequency of rhinovirus and mixed viral detections in these patients. In conclusion, according to the requirements of speed and low cost of the methods, and to achieve the highest rate of detection of respiratory viruses, the combined use of DFA and m‐PCR is today likely to be the best way to improve diagnosis of respiratory illnesses in children. J. Med. Virol. 78:1498–1504, 2006. © 2006 Wiley‐Liss, Inc.

Sensitivity of detection of rhinoviruses in spiked clinical samples by nucleic acid sequence-based amplification in the presence of an internal control

The objectives of the study were to determine the sensitivity of Nucleic Acid Sequence-Based Amplification (NASBA) for the detection of rhinovirus (RV) serotype 15 in water and in spiked respiratory specimens in the presence of a newly developed internal control (IC). The sensitivity of NASBA on RNA was 10 molecules per reaction. The sensitivity of RV NASBA on RV-15 in water and in respiratory specimens was equal to that in tissue culture. Addition of 10(4) molecules of rhinovirus internal control (RV IC) did not affect the sensitivity. Viral RNA should be extracted from clinical specimens as rapidly as possible after collection, since loss of detectable RNA occurs after 2 h. NASBA allows a sensitive detection of RV RNA in spiked respiratory specimens in the presence of an internal control.

Development of three multiplex RT-PCR assays for the detection of 12 respiratory RNA viruses

Three multiplex hemi-nested RT-PCR assays were developed to detect simultaneously 12 RNA respiratory viruses: influenza viruses A, B and C, human respiratory syncytial virus (hRSV), human metapneumovirus (hMPV), parainfluenza virus types 1-4 (PIV-1, -2, -3 and -4), human coronavirus OC43 and 229E (HCoV) and rhinovirus (hRV). An internal amplification control was included in one of the RT-PCR assays. The RT-PCR multiplex 1 and the hemi-nested multiplex 1 detected 1 and 0.1 TCID50 of RSV A, respectively, and 0.01 and 0.001 TCID50 of influenza virus A/H3N2, respectively. Two hundred and three nasal aspirates from hospitalised children were retrospectively tested in comparison with two conventional methods: direct immunofluorescence assay and viral isolation technique. Almost all samples (89/91) that were positive by immunofluorescence assay and/or viral isolation technique were detected by the multiplex assay. This method also detected an additional 85 viruses and 33 co-infections. The overall sensitivity (98%), rapidity and enhanced efficiency of these multiplex hemi-nested RT-PCR assays suggest that they would be a significant improvement over conventional methods for the detection of a broad spectrum of respiratory viruses.