Nasopharyngeal Aspirate Samples Research Articles

Detection of respiratory viruses and bacteria in children using a twenty-two target reverse-transcription real-time PCR (RT-qPCR) panel.

BackgroundRapid detection of the wide range of viruses and bacteria that cause respiratory infection in children is important for patient care and antibiotic stewardship. We therefore designed and evaluated a ready-to-use 22 target respiratory infection reverse-transcription real-time polymerase chain reaction (RT-qPCR) panel to determine if this would improve detection of these agents at our pediatric hospital.MethodsRT-qPCR assays for twenty-two target organisms were dried-down in individual wells of 96 well plates and saved at room temperature. Targets included 18 respiratory viruses and 4 bacteria. After automated nucleic acid extraction of nasopharyngeal aspirate (NPA) samples, rapid qPCR was performed. RT-qPCR results were compared with those obtained by the testing methods used at our hospital laboratories.ResultsOne hundred fifty-nine pediatric NPA samples were tested with the RT-qPCR panel. One or more respiratory pathogens were detected in 132/159 (83%) samples. This was significantly higher than the detection rate of standard methods (94/159, 59%) (P<0.001). This difference was mainly due to improved RT-qPCR detection of rhinoviruses, parainfluenza viruses, bocavirus, and coronaviruses. The panel internal control assay performance remained stable at room temperature storage over a two-month testing period.ConclusionThe RT-qPCR panel was able to identify pathogens in a high proportion of respiratory samples. The panel detected more positive specimens than the methods in use at our hospital. The pre-made panel format was easy to use and rapid, with results available in approximately 90 minutes. We now plan to determine if use of this panel improves patient care and antibiotic stewardship.

Concordancia entre las técnicas de IFD, PCR y ELISA para determinar la frecuencia de Bordetella parapertussis y Bordetella pertussis en un brote de tos ferina en el departamento de Antioquia (Colombia) en 2013

Objective: To determine the correlation between diagnostic techniques and to confirm the diagnosis of probable cases of whooping cough captured by direct immunofluorescence (DIF) during an outbreak in 2013 in the department of Antioquia. Materials and methods: We analysed the demographic, clinical, and epidemiological data and the laboratory results of probable cases of whooping cough confirmed by DIF at a peak of whooping cough in 2013 in the department of Antioquia. The nasopharyngeal aspirate and serum samples were collected and received between the epidemiological periods IV - VII of 2013. All patients confirmed by DIF were confirmed by polymerase chain reaction (PCR) and/or enzyme-linked immunosorbent assay (ELISA). The analysis of agreement was performed using the kappa index. Results: Of the 180 samples processed in the public health laboratory of Antioquia, 134 (74%) were positive using the DIF technique of which 109 samples were confirmed by PCR, with 24 (22%)samples positive for B. parapertussis , 3 (2.8%) for B. pertussis , 17 (15.6%) for Bordetella spp. and18 (16.5%) for mixed infection by B. pertussis and B. parapertussis . Of the 81 cases confirmed by ELISA, 31 (38.3%) were positive. In the municipality of La Estrella, the mean age of the confirmed cases was 6.6 years, and the median was 3 years (range, 2-4 years). For the municipality of Medellin, the mean age was 28.7 years, and the median was 25 years (range, 12-42 years). For most of the symptoms, there were no significant differences, except for paroxysmal cough among the confirmed cases of B. parapertussis and B. pertussis ( p = <.04) in the municipality of La Estrella. According to the kappa index, the results showed poor correlation strength and no agreement with the results of the PCR and ELISA tests compared with DIF, kappa index: (DIF/PCR: K = 0.0944) and (DIF/ELISA: K = - 0.4533). Conclusions: During this analysis in 2013, Antioquia was affected by the circulation of B. parapertussis and B. pertussis in the adolescent and adult population in Medellin and the 2-4 year-old population in La Estrella. Currently, PCR and ELISA are the recommended techniques for diagnosing whooping cough. Due to its subjectivity and low correlation, DIF is in disuse.

Respiratory Infections and Activity of Anti-Flu Vaccine in Patients with Lymphoma and Multiple Myeloma

Introduction: The significance of viral respiratory infections (VRI) and efficacy of anti-flu vaccine in patients (pts) with lymphoproliferative malignancies (LPM) have not been fully elucidated. The current large comprehensive study was designed to evaluate the incidence of respiratory infections in LPM pts, define clinical significance of VRI and assess the impact of anti-flu vaccine on RI prevention in this population.Methods: All consecutive pts, diagnosed either with non-Hodgkin lymphoma (NHL) or multiple myeloma (MM), followed at the Rambam Hematology Outpatient Unit between 01/2011 and 03/2012 (during or after anti-cancer therapy or untreated) were evaluated. Data regarding anti-lymphoma/MM therapy used, respiratory infections occurring during the study period, tests performed to assess these infections (focusing on viral ones), administration of anti-flu vaccine and infection-related outcome were recorded. Samples of nasopharyngeal aspirate (NPA) or bronchoalveolar lavage (BAL) were evaluated for VRI pathogens using both immunofluorescence and polymerase chain reaction (PCR) methods.Results: Five hundred and sixty two respiratory infection episodes were reported in 369 pts. In 224 (40%) episodes, VRI investigation was performed using either NPA (n=180) or BAL (n=44) samples. The decision regarding the sample source was taken based on the respiratory infection severity.The cohort screened for VRI included a larger proportion of pts receiving anti-cancer therapy during the study period than the non-screened cohort (70% vs 30%, respectively, p<0.01). The number of respiratory episodes requiring hospitalization for their respiratory infection was higher in the former cohort (54% vs 18%). One hundred fifty two screened episodes were community-acquired (50 required hospitalization) and 72 were hospital-acquired.Fever was the most common clinical symptom in screened episodes (n=111, 50%), followed by cough (n=91, 41%), dyspnea (n= 87, 39%), runny nose (n=47, 21%), respiratory distress (n=45, 20%): with decreased O2 saturation (n=35, 16%) and mechanical ventilation (n=10, 4%). In 12% and 23% of episodes, respectively, neutropenia and significant hypogammaglobinemia (IgG <500 mg/dl) were revealed.VRI were identified in 66/224 episodes (29%), 59 episodes were viral infections and 7 - co-infections (viral with another pathogen). Sixty viral episodes were diagnosed in pts with upper respiratory tract infections and 6 in pts with pneumonia.Cough, abnormal lung physical findings and hypogammaglobinemia were statistically more frequent in pts with viral infections vs those with other respiratory infections. Viral infections were treated according to pathogens recognized. Tamiflu was prescribed for influenza infections and ribavirin was given for part of the respiratory syncytial virus (RSV) infections. Supportive treatment only was given for parainfluensa and metapneumovirus infections.Twelve episodes of VRI, developed outside of hospital, required hospitalization (5%) and 2 of these episodes resulted in death. The most frequent viral infection was Influenza A (22 cases), followed by RSV (14 cases), parainfluenza and metapneumovirus (11 cases each). Less frequent viral pathogens were Influenza B (6 cases), and adenovirus (2 cases). Seven cases (10%) were accompanied with a secondary bacterial or fungal infection. Notably, 3 of the 10 pts diagnosed with RSV infection had a concurrent Aspergillus infection.Data regarding anti-flu vaccination were available in 701 pts; 431 pts (61%) were vaccinated. In a univariate analysis, anti-flu vaccination was found to have no impact on the respiratory infection frequency (51% vs 48.9%, p=0.752).Among pts with VRI, 49% did and 45% did not previously receive anti-flu vaccination (p=0.95). This vaccination had no effect on the VRI incidence in the investigated episodes.Conclusions: VRI, although frequent, are usually associated with a good outcome in LPM pts. Presence of cough and abnormal pulmonary examination were found to predict a positive screen for a viral pathogen. Influenza and RSV, both potentially treatable with Tamiflu and ribavirin, respectively, were responsible for 55% of VRI episodes, justifying a wider use of viral screening in LPM pts. Anti-flu vaccination has not proved its efficacy either in preventing viral infections or in reducing the entire incidence of respiratory infections in these pts. DisclosuresNo relevant conflicts of interest to declare.

Impact of bacteria in nasal aspirates on disease severity of bronchiolitis

Background: The effect of potentially pathogenic bacteria (PPB) on disease severity in patients with bronchiolitis is understudied. Methods: This prospective study was carried out in the Children's Hospital of Soochow University during the 2012–2013 autumn and winter seasons. We enrolled consecutive children < 2 years of age hospitalized with an attending physician's diagnosis of bronchiolitis. Nasopharyngeal aspirate samples were tested for multiple respiratory viruses and cultured for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus. Results: In all, 30% (188 patients) were positive for Strep. pneumoniae, H. influenzae, M. catarrhalis, and Staph. aureus. Length of stay (LOS) for patients with PPB was 4.0 days (interquartile range, IQR, 25th–75th percentile: 3.0–6.0 days) versus 3.0 days (IQR, 3.0–5.0 days) for patients without PPB (p < 0.001). However, requirement and duration of supplemental oxygen were not significantly different between the two groups. H. influenzae was an independent risk factor for hospital LOS ≥ 5.0 days (adjusted odds ratio, 1.75; 95% confidence interval, 1.06–2.91). The presence of PPB was not associated with increased risk of supplemental oxygen requirement. Conclusions: Our study demonstrated that pediatricians should evaluate for PPB in patients with bronchiolitis, especially when they present with RSV infection, fever or percentage of neutrophils > 40%. The presence of H. influenzae in nasal aspirates is associated with longer LOS in patients with bronchiolitis.

Parainfluenza virus as a cause of acute respiratory infection in hospitalized children

BackgroundHuman parainfluenza viruses account for a significant proportion of lower respiratory tract infections in children. ObjectiveTo assess the prevalence of Human parainfluenza viruses as a cause of acute respiratory infection and to compare clinical data for this infection against those of the human respiratory syncytial virus. MethodsA prospective study in children younger than five years with acute respiratory infection was conducted. Detection of respiratory viruses in nasopharyngeal aspirate samples was performed using the indirect immunofluorescence reaction. Length of hospital stay, age, clinical history and physical exam, clinical diagnoses, and evolution (admission to Intensive Care Unit or general ward, discharge or death) were assessed. Past personal (premature birth and cardiopathy) as well as family (smoking and atopy) medical factors were also assessed. ResultsA total of 585 patients were included with a median age of 7.9 months and median hospital stay of six days. No difference between the HRSV+ and HPIV+ groups was found in terms of age, gender or length of hospital stay. The HRSV+ group had more fever and cough. Need for admission to the Intensive Care Unit was similar for both groups but more deaths were recorded in the HPIV+ group. The occurrence of parainfluenza peaked during the autumn in the first two years of the study. ConclusionParainfluenza was responsible for significant morbidity, proving to be the second-most prevalent viral agent in this population after respiratory syncytial virus. No difference in clinical presentation was found between the two groups, but mortality was higher in the HPIV+ group.

Viral respiratory tract infections in the neonatal intensive care unit.

IntroductionViral respiratory infections cause major morbidity and mortality in preterm infants. We have performed a prospective study in our neonatal intensive care unit (NICU) to determine the incidence of respiratory infections, their impact and the epidemiology and outcome in high risk neonates.Patients and methodsFrom September 2011 to May 2013 a prospective study was conducted in all preterm infants <32 weeks gestational age and in all term newborns admitted to NICU for any pathology that was anticipated to have an admission exceeding two weeks. A nasopharyngeal aspirate (NPA) was collected the first day of life and weekly until discharge for virologic study with polymerase chain reaction. When these babies presented respiratory symptoms a new NPA was collected at this moment. A clinical form was filled by the physician.ResultsA total of 60 infants were analysed: 30 (50%) had a gestational age <32 weeks and 36 (60%) weighed less than 1500 g. We collected a total of 256 nasopharyngeal aspirate samples, 24 of them being positive (9.3%). These 24 positive samples corresponded to 13 infants in our cohort (21.6% of the patients). Of them, 9 were symptomatic and had 11 episodes of infection (2 patients had two different episodes with negative control between them). The most frequently identified virus was rhinovirus in (19) 79% of cases. The most frequent clinical data was the presence or increase in apneas (75%) and the need for oxygenotherapy.ConclusionsHRV infections are prevalent in the NICU, and preterm infants have a high risk of infections with clinical relevance.

Diagnosis of human metapneumovirus in patients hospitalized with acute lower respiratory tract infection using a metal-enhanced fluorescence technique

Human metapneumovirus (hMPV) is a common respiratory tract infection in children. However, conventional immunofluorescence assays (IFAs) for detecting hMPV in respiratory samples have limited reliability with a sensitivity and false-negative predictive value of 58.1% and approximately 17.8%, respectively. In this study, hMPV was measured in 91 clinical respiratory samples (55 sputum and 36 nasopharyngeal aspirate samples), which were obtained from children under three years of age, utilizing our previously developed high-throughput metal-enhanced fluorescence (MEF)-based biosensor (HT-MEFB). The sensitivity of HT-MEFB for hMPV detection in the 91 samples was improved by up to 77.4% compared with that obtained with IFAs, and the specificity of HT-MEFB for hMPV detection was 91.7%. In addition, the specificity and accuracy obtained after the selection of 55 sputum samples as the analyzed specimen reached 92.3% and 90.9%, respectively. Thus, in terms of accuracy, high throughput, and sensitivity, HT-MEFB exhibits considerable potential for hMPV detection in clinical settings.

Diagnosis of pertussis using nasopharyngeal IgA and polymerase chain reaction in specimens from outpatients in Australia.

We assessed IgA antibodies and polymerase chain reaction (PCR) for diagnosis of pertussis in nasopharyngeal aspiration (NPA) samples from outpatients in Australia. A total of 1700 patients (849 adults, 851 children) from Western Australia and the Northern Territory fulfilled the laboratory case definition for pertussis between 2004 and 2013: 732 specimens were positive by NPA IgA alone, 559 by PCR alone, and 409 by both tests. Overall, 968 cases (56.8%) were positive by PCR and 1141 cases (67.2%) by IgA [p < 0.00025]. Among pediatric patients, PCR was positive in 524 (61.3%) and IgA in 569 (67%). In 849 adult cases, the respective proportions were 52.3% and 67.4% [p < 0.00025]. The duration of cough in 507 patients was shorter in 262 pediatric cases (mean, 2.51 weeks; standard deviation [SD], 2.25) than 245 adult patients (3.27 weeks; SD, 2.79) [p = 0.0009]. PCR positivity showed a season-dependent variance (range, 5.6 to 85.9%) and peaked in the second week (71.7%) of illness. IgA antibodies peaked in the fifth week (89.5%) postinfection, and the positivity rate for NPA IgA was less variable (range, 38.3-97.2%). Nasopharyngeal Bordetella pertussis-specific IgA antibodies are valuable in diagnosis of pertussis in Australia. Reliance on PCR alone misses a significant proportion of pertussis cases, especially those with a delayed presentation.

PO-0197 Bacterial Culture Versus Pcr For Etiologic Diagnosis Of Community Acquired Pneumonia- Results From Capes (community Acquired Pneumonia Etiology Study)

Background PCR technologyholds promise to overcome the limitations of bacterial culture for confirming bacterial aetiology in childhood pneumonia. Aims To compare the diagnostic yield using bacterial culture versus PCR in a cohort of children with community acquired pneumonia (CAP). Methods CAPES is single-centre cohort study of 2000 consecutively enrolled children (1 month-12 years) with CAP(World Health Organisation definition). All underwent blood and nasopharyngeal aspirate (NPA) culture for bacteria. In addition, a randomly selected sub-group (10%,n = 200) underwent multiplex PCR on NPA samples to identify eight pathogenic bacteria. Results In the sub-cohort of 200 children, pathogenic organisms were isolated from blood and NPA in 4(2%) and 30(15%) respectively (Figure 1). The main cohort showed similar proportions (1.7% and 14.0%) and distribution of organisms, suggesting absence of selection bias. Multiplex PCR(Figure 2) yielded traces of bacteria in 193(96.5%),with one organism detected in 44(22%), two in 76(38%), three in 53(26.5%), and four in 20(10%). Etiologic diagnosis could be confirmed by bacterial culture in4.5% cases, whereas PCR confirmed in 22%. Conclusion Bacterial culture techniques appear to have limited sensitivity for etiologic diagnosis, whereas PCR has much higher sensitivity, although detection of multiple pathogenic bacteria precluded confirmation of aetiology in the majority.

Hospital length-of-stay is associated with rhinovirus etiology of bronchiolitis.

To determine whether hospital length-of-stay (LOS) for bronchiolitis is influenced by the causative virus: respiratory syncytial virus (RSV) or rhinovirus. This prospective study was carried out in 3 university hospitals in Finland during 2 consecutive winter seasons. We enrolled consecutive children <2 years of age hospitalized with an attending physician's diagnosis of bronchiolitis. All enrolled children were included in the primary analysis. A parallel analysis was also conducted using a stricter definition for bronchiolitis (age <12 months and no history of wheeze). Polymerase chain reaction was used to test the nasopharyngeal aspirate samples for multiple respiratory pathogens. The median age of the 408 children was 8 months, 73% had no history of wheeze and their median hospital LOS was 2 days. 144 (35%) children had RSV only and 92 (23%) children rhinovirus only infections. Children with rhinovirus only had shorter duration of prehospital symptoms, higher disease severity score at entry and more often a history of wheezing (all P ≤ 0.001). Controlling for 7 demographic and clinical characteristics, those with rhinovirus only had shorter hospital LOS when compared with children with RSV only (adjusted odds ratio: 0.45; 95% confidence interval: 0.22-0.92; P = 0.03). The rhinovirus only finding was similar in the subset of 206 children with stricter diagnosis (adjusted odds ratio: 0.30; 0.06-1.49; P = 0.14). Hospital LOS is associated with rhinovirus etiology of bronchiolitis. Our data call attention to the importance of both RSV and rhinovirus testing in clinical research.

Infecciones virales de las vías respiratorias en la Unidad de Cuidados Intensivos Neonatales

IntroductionViral respiratory infections cause major morbidity and mortality in preterm infants. We have performed a prospective study in our neonatal intensive care unit (NICU) to determine the incidence of respiratory infections, their impact and the epidemiology and outcome in high risk neonates. Patients and methodsFrom September 2011 to May 2013 a prospective study was conducted in all preterm infants < 32 weeks gestational age and in all term newborns admitted to NICU for any pathology that are anticipated to have an income exceeding two weeks. A nasopharyngeal aspirate (NPA) was collected the first day of life and weekly until discharge for virologic study with polymerase chain reaction. When these babies presented respiratory symptoms a new NPA was collected in this moment. A clinical form was filled by the physician. ResultsA total of 60 infants were analyzed: 30 (50%) had a gestational age < 32 weeks and 36 (60%) weighing less than 1500 grams. We collected a total of 256 nasopharyngeal aspirate samples, 24 of them being positive (9.3%). These 24 positive samples corresponded to 13 infants in our cohort (21.6% of the patients). Of them, 9 were symptomatic and had 11 episodes of infection (2 patients had two different episodes with negative control between them). The most frequently identified virus was rhinovirus in (19) 79% of cases. The most frequent clinical data was the presence or increased of apneas (75%) and the needed of oxygenotherapy. ConclusionsHRV infections are prevalent in the NICU, and preterm infants have a high risk of infections with clinical relevance.

Acute respiratory viral infections in pediatric cancer patients undergoing chemotherapy

Objectiveto estimate the prevalence of infection by respiratory viruses in pediatric patients with cancer and acute respiratory infection (ARI) and/or fever. Methodscross‐sectional study, from January 2011 to December 2012. The secretions of nasopharyngeal aspirates were analyzed in children younger than 21 years with acute respiratory infections. Patients were treated at the Grupo em Defesa da Criança Com Câncer (Grendacc) and University Hospital (HU), Jundiaí, SP. The rapid test was used for detection of influenza virus (Kit Biotrin, Inc. Ireland), and real‐time multiplex polymerase chain reaction (FTD, Respiratory pathogens, multiplex Fast Trade Kit, Malta) for detection of influenza virus (H1N1, B), rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus, human parechovirus, bocavirus, metapneumovirus, and human coronavirus. The prevalence of viral infection was estimated and association tests were used (χ2 or Fisher's exact test). Results104 samples of nasopharyngeal aspirate and blood were analyzed. The median age was 12 ± 5.2 years, 51% males, 68% whites, 32% had repeated ARIs, 32% prior antibiotic use, 19.8% cough, and 8% contact with ARIs. A total of 94.3% were in good general status. Acute lymphocytic leukemia (42.3%) was the most prevalent neoplasia. Respiratory viruses were detected in 50 samples: rhinoviruses (23.1%), respiratory syncytial virus AB (8.7%), and coronavirus (6.8%). Co‐detection occurred in 19% of cases with 2 viruses and in 3% of those with 3 viruses, and was more frequent between rhinovirus and coronavirus 43. Fever in neutropenic patients was observed in 13%, of which four (30.7) were positive for viruses. There were no deaths. Conclusionsthe prevalence of respiratory viruses was relevant in the infectious episode, with no increase in morbidity and mortality. Viral co‐detection was frequent in patients with cancer and ARIs.

Viral lung infections

The avian influenza A(H7N9) virus has jumped species barrier and caused severe human infections. Here, we present the virological features relevant to clinical practice, and summarize the epidemiology, clinical findings, diagnosis, treatment, and preventive strategies of A(H7N9) infection. As of 18 February 2014, A(H7N9) virus has caused 354 infections in mainland China, Taiwan, and Hong Kong with a case-fatality rate of 32%. Elderly men were most affected. Most patients acquired the infection from direct contact with poultry or from a contaminated environment, although person-to-person transmission has likely occurred. A(H7N9) infection has usually presented with severe pneumonia, often complicated by acute respiratory distress syndrome and multiorgan failure. Mild infections have been reported in children and young adults. Nasopharyngeal aspirate and sputum samples should be collected for diagnosis, preferably using reverse transcriptase-PCR. Early treatment with neuraminidase inhibitors improved survival, but the efficacy of antivirals was hampered by resistant mutants. The closure of live poultry markets in affected areas has significantly contributed to the decline in the incidence of human cases. The emergence of A(H7N9) virus represents a significant health threat. High vigilance is necessary so that appropriate treatment can be instituted for the patient and preventive measures can be implemented.

Clinical and epidemiological profiles of lower respiratory tract infection in hospitalized children due to human bocavirus in a subtropical area of China.

Lower respiratory tract infection is a major cause of morbidity and mortality in children. Human bocavirus (HBoV) is confirmed to have an association with pediatric lower respiratory tract infection. Seasonal and meteorological factors may play a key role in the epidemiology of HBoV. The purpose of this study was to ascertain the frequency, season, and clinical characteristics of hospitalized children with HBoV infection. In addition, an evaluation of the effects of meteorological factors on the incidence of HBoV in a subtropical area in China will be conducted. Children were <14 years in age and hospitalized for lower respiratory tract infection between January 1, 2009 and December 31, 2012 in the Respiratory Disease Department at the Children's Hospital affiliated to Soochow University. Multi‐pathogens were detected in nasopharyngeal aspirate samples. The association between HBoV activity and regional meteorological conditions was analyzed. The average incidence of HBoV infection was 6.6% (502/7,626). Of the 502 HBoV positive children, the median age was 13 months (range 1–156 months). The HBoV infection rate was highest among the 7–12 months groups (12.9%, 163/1,267). Seasonal distribution of HBoV was noted during June to November, especially during the summer season (June to August). HBoV activity was associated with temperature and humidity although the lag effect between temperature and HBoV activity observed. HBoV is one of the most common viral pathogens in children with lower respiratory tract infection. HBoV infection occurs throughout the year with a peak during the summer. Temperature and humidity may affect the incidence of HBoV. J. Med. Virol. 86:2154–2162, 2014. © 2014 Wiley Periodicals, Inc.

Acute respiratory viral infections in pediatric cancer patients undergoing chemotherapy

Objectiveto estimate the prevalence of infection by respiratory viruses in pediatric patients with cancer and acute respiratory infection (ARI) and/or fever. Methodscross-sectional study, from January 2011 to December 2012. The secretions of nasopharyngeal aspirates were analyzed in children younger than 21 years with acute respiratory infections. Patients were treated at the Grupo em Defesa da Criança Com Câncer (Grendacc) and University Hospital (HU), Jundiaí, SP. The rapid test was used for detection of influenza virus (Kit Biotrin, Inc. Ireland), and real-time multiplex polymerase chain reaction (FTD, Respiratory pathogens, multiplex Fast Trade Kit, Malta) for detection of influenza virus (H1N1, B), rhinovirus, parainfluenza virus, adenovirus, respiratory syncytial virus, human parechovirus, bocavirus, metapneumovirus, and human coronavirus. The prevalence of viral infection was estimated and association tests were used (χ2 or Fisher's exact test). Results104 samples of nasopharyngeal aspirate and blood were analyzed. The median age was 12 ± 5.2 years, 51% males, 68% whites, 32% had repeated ARIs, 32% prior antibiotic use, 19.8% cough, and 8% contact with ARIs. A total of 94.3% were in good general status. Acute lymphocytic leukemia (42.3%) was the most prevalent neoplasia. Respiratory viruses were detected in 50 samples: rhinoviruses (23.1%), respiratory syncytial virus AB (8.7%), and coronavirus (6.8%). Co-detection occurred in 19% of cases with 2 viruses and in 3% of those with 3 viruses, and was more frequent between rhinovirus and coronavirus 43. Fever in neutropenic patients was observed in 13%, of which four (30.7) were positive for viruses. There were no deaths. Conclusionsthe prevalence of respiratory viruses was relevant in the infectious episode, with no increase in morbidity and mortality. Viral co-detection was frequent in patients with cancer and ARIs.

Respiratory virus infections among children in South China

Acute respiratory tract infection is an important cause of morbidity and mortality with a worldwide disease burden. This study aimed to determine the prevalence and clinical characteristics of children with viral-induced acute respiratory tract infection, in Southern China. Nasopharyngeal aspirate samples from 1,980 pediatric patients with suspected acute respiratory tract infection, and 82 samples from healthy subject controls were collected for routine examination at the Second Affiliated Hospital of Shantou University Medical College, from October 2007 to August 2011. Specimens were tested by multiplex polymerase chain reaction (mPCR). At least one or more viruses were detected from 1,087 samples (54.9%). These included laboratory confirmations for 446 respiratory syncytial virus (RSV), 386 influenza virus A (FluA), 315 human rhinovirus (HRV), 135 human bocavirus (HBoV), 119 Parainfluenza virus 3 (PIV3), 82 Parainfluenza virus 1 (PIV1), 66 adenovirus (ADV), 53 WU polyomavirus (WUPyV), 52 human metapneumovirus (hMPV), and 29 influenza virus B (FluB) samples. Samples from healthy subjects were negative for any virus. Of the patients with positive specimens, 107 (9.8%) were admitted to pediatric intensive care unit (PICU). Co-infection with at least two of the viral pathogens under study was observed in 325 of the 1,980 patients (16.4% of the total number of cases). These findings may help in the diagnosis of viral infections of the respiratory tract in children, and help to consider current and potential therapeutic approaches for the treatment of acute respiratory tract infection, and further respiratory complications.

Evaluation of respiratory syncytial virus group A and B genotypes among nosocomial and community-acquired pediatric infections in southern Brazil

BackgroundRespiratory syncytial virus (RSV) is the main cause of lower respiratory tract illness in children worldwide. Molecular analyses show two distinct RSV groups (A and B) that comprise different genotypes. This variability contributes to the capacity of RSV to cause yearly outbreaks. These RSV genotypes circulate within the community and within hospital wards. RSV is currently the leading cause of nosocomial respiratory tract infections in pediatric populations. The aim of this study was to evaluate the G protein gene diversity of RSV amplicons.MethodsNasopharyngeal aspirate samples were collected from children with nosocomial or community-acquired infections. Sixty-three RSV samples (21 nosocomial and 42 community-acquired) were evaluated and classified as RSV-A or RSV-B by real-time PCR. Sequencing of the second variable region of the G protein gene was performed to establish RSV phylogenetics.ResultsWe observed co-circulation of RSV-A and RSV-B, with RSV-A as the predominant group. All nosocomial and community-acquired RSV-A samples were from the same phylogenetic group, comprising the NA1 genotype, and all RSV-B samples (nosocomial and community-acquired) were of the BA4 genotype. Therefore, in both RSV groups (nosocomial and community-acquired), the isolates belonged to only one genotype in circulation.ConclusionsThis is the first study to describe circulation of the NA1 RSV genotype in Brazil. Furthermore, this study showed that the BA4 genotype remains in circulation. Deciphering worldwide RSV genetic variability will aid vaccine design and development.

Clinical and epidemiological aspects related to the detection of adenovirus or respiratory syncytial virus in infants hospitalized for acute lower respiratory tract infection

ObjectiveTo characterize and compare clinical, epidemiological, and laboratory aspects ofinfants with acute lower respiratory infection (ALRI) associated with the detection of adenovirus(ADV) or respiratory syncytial virus (RSV). MethodsA preliminary respiratory infection surveillance study collected samples of nasopharyngeal aspirate (NPA) for viral research, linked to the completion of a standard protocol, from children younger than two years admitted to a university hospital with ALRI, between March of 2008 and August of 2011. Polymerase chain reaction (PCR) was used for eight viruses: ADV, RSV, metapneumovirus, Parainfluenza 1, 2, and 3, and Influenza A and B. Cases with NPA collectedduring the first 24hours of admission, negative results of blood culture, and exclusive detection of ADV (Gadv group) or RSV (Grsv group) were selected for comparisons. ResultsThe preliminary study included collection of 1,121 samples of NPA, 813 collected in thefirst 24hours of admission, of which 50.3% were positive for at least one virus; RSV was identifiedin 27.3% of cases surveyed, and ADV was identified in 15.8%. Among the aspects analyzed inthe Gadv (n = 58) and Grsv (n = 134) groups, the following are noteworthy: the higher meanage, more frequent prescription of antibiotics, and the highest median of total white blood cellcount and C-reactive protein values in Gadv. ConclusionsPCR can detect persistent/latent forms of ADV, an aspect to be considered wheninterpreting results. Additional studies with quantitative diagnostic techniques could elucidatethe importance of the high frequency observed.

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Apnea in Children Hospitalized With Bronchiolitis

To identify risk factors for inpatient apnea among children hospitalized with bronchiolitis. We enrolled 2207 children, aged <2 years, hospitalized with bronchiolitis at 16 sites during the winters of 2007 to 2010. Nasopharyngeal aspirates (NPAs) were obtained on all subjects, and real-time polymerase chain reaction was used to test NPA samples for 16 viruses. Inpatient apnea was ascertained by daily chart review, with outcome data in 2156 children (98%). Age was corrected for birth <37 weeks. Multivariable logistic regression was performed to identify independent risk factors for inpatient apnea. Inpatient apnea was identified in 108 children (5%, 95% confidence interval [CI] 4%-6%). Statistically significant, independent predictors of inpatient apnea included: corrected ages of <2 weeks (odds ratio [OR] 9.67) and 2 to 8 weeks (OR 4.72), compared with age ≥ 6 months; birth weight <2.3 kg (5 pounds; OR 2.15), compared with ≥ 3.2 kg (7 pounds); caretaker report of previous apnea during this bronchiolitis episode (OR 3.63); preadmission respiratory rates of <30 (OR 4.05), 30 to 39 (OR 2.35) and >70 (OR 2.26), compared with 40 to 49; and having a preadmission room air oxygen saturation <90% (OR 1.60). Apnea risk was similar across the major viral pathogens. In this prospective, multicenter study of children hospitalized with bronchiolitis, inpatient apnea was associated with younger corrected age, lower birth weight, history of apnea, and preadmission clinical factors including low or high respiratory rates and low room air oxygen saturation. Several bronchiolitis pathogens were associated with apnea, with similar apnea risk across the major viral pathogens.