Advances on molecular typing methods and evolution of human parainfluenza virus / 中华预防医学杂志

Human parainfluenza viruses (HPIVs) is one of the main causes of acute respiratory tract infections in children. HPIVs have been grouped into four serotypes (HPIV1~HPIV4) according to serological and genetic variation. Different serotypes of HPIVs have diverse clinical disease spectrum, epidemic characteristics and disease burden. Based on the nucleotide variation in structural protein genes, HPIVs can be further divided into distinct genotypes and subtypes with diverse temporal and spatial distribution features. The standard molecular typing methods are helpful to clarify the gene evolution and transmission patterns of HPIVs in the process of population transmission. However, the development of molecular epidemiology of HPIVs has been hindered by the lack of a standardized molecular typing method worldwide. Therefore, this study reviewed the viral characteristics, genome structure, existing genotyping methods and evolution of HPIVs, and screened the reference strains for molecular typing, so as to improve the understanding of gene characteristics and molecular typing of HPIVs, and provide an important scientific basis for the monitoring and research of molecular epidemiology of HPIVs in China.

Epidemiology and Clinical Severity of the Hospitalized Children with Viral Croup

PURPOSE: In this study, the clinical and epidemiological characteristics of patients admitted for viral croup were analyzed to evaluate disease severity based on the organism that caused the infection. METHODS: We retrospectively reviewed the medical records of 302 patients who were admitted to the Department of Pediatrics at the Wonju Severance Hospital between May 2013 and December 2016 for viral croup. Patients who showed positive results on multiplex polymerase chain reaction were subsequently diagnosed with respiratory virus infection. The Westley scoring system was used to evaluate the severity of viral croup. RESULTS: Of the 302 patients, 149 were admitted due to severe viral croup, including 88 boys and 61 girls, with a boy-to-girl ratio of 1.44:1. About 110 cases of parainfluenza virus infection have been reported, which accounted for almost half of the total cases. The other identified viruses included influenza virus, human rhinovirus, and respiratory syncytial virus. Analysis of the association between severe viral croup and causative pathogen revealed that only parainfluenza type 2 virus showed a significantly high risk. Parainfluenza type 2 virus did not show an age-based difference in frequency but showed relatively a higher frequency of infections during the summer and fall. CONCLUSIONS: In this study, parainfluenza virus type 2 was the only virus associated with severe viral croup. To facilitate proper preventive management, treatment, and prognosis evaluation of viral croup, prospective and multicenter studies should assess the additional variables and the severity of the virus. Additionally, further studies should be conducted to assess age-dependent influences, as well as the regional and seasonal incidence of viral infection.

Viral agents causing acute lower respiratory tract infections in hospitalized children at a tertiary care center in Saudi Arabia

To determine the load and importance of respiratory viruses in hospitalized Saudi children with acute lower respiratory tract infections [ALRIs]. A retrospective study was performed in the Departments of Pediatrics, Pathology/Microbiology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from January 2005 to December 2010. Nasopharyngeal aspirates were collected from 643 children with ALRI. Viruses were detected by direct immunofluorescence, respiratory syncytial virus [RSV], adenovirus [ADV], type 1 to 3 parainfluenza viruses [PIV], and type A and B influenza virus [flu]. Of the 643 children with ALRI, viruses were detected in 309 [48.1%] specimens. The viruses that were identified included RSV [n=295, 95.5%], PIV [n=8, 1.2%], ADV [n=2, 0.3%], flu A [n=2, 0.3%], and flu B [n=2, 0.3%]. The RSV was predominated in 231 [75%] children less than one year of age. Only younger age and male gender were associated with severe illness. The peak frequency of the viruses detected was in the winter. Of the 309 virus positive samples, bronchiolitis was detected in 81.2% [n=251], and pneumonia in 14.2% [n=44] [p<0.0001]. Viruses are an important cause of ALRIs in Saudi children constituting approximately 48.1% of the total cases. The RSV is the most common pathogen [95.5%] causing ALRIs. Most of the children were younger than one year of age, and were more likely to present with bronchiolitis than pneumonia

Simultaneous detection of human parainfluenza viruses 1, 2, 3 by multiplex real-time reverse transcription-polymerase chain reaction with LNA probes / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Human parainfluenza virus (HPIV) types 1, 2 and 3 are major viral pathogens responsible for upper and lower respiratory tract infections. In this study, a real-time RT-PCR was developed using multiplex primers-probe (HPIV-1, 2, 3) for the simultaneous detection of both HPIV1, HPIV2 and HPIV3 genomes.</p><p><b>METHODS</b>Optimal primers and probes were designed using specialized software. The conditions for multiplex real-time RT-PCR had been optimized. The synthesis of RNA standards of HPIV1, 2, 3 were used a T7 RNA polymerase. Check the specificity sensitivities and stability of one step RT-PCR assay.</p><p><b>RESULTS</b>Obtained in a 10-fold dilution series assay demonstrate a high sensitivity of the assay with a lowest detection limit of 10 copies for HPIV1, 100 copies for HPIV2 and 100 copies for HPIV3.</p><p><b>CONCLUSION</b>The assays demonstrates an improved sensitivity and scope of detecting HPIV1, 2, 3 viruses relative to routine antigen detection assays while the quantitative utility may facilitate investigation of the pre-diagnosis and respiratory virus pathogenesis.</p>

An atomic force microscopy study on the images of para influenza virus under different treatment conditions / 生物医学工程学杂志

Using atomic force microscope (AFM), we investigated the images of Pars influenza virus (PIV) under different treatment conditions and observed the different appearances of the virus and its ultra-microstructure from the exterior to the interior. From the 2D images under transmission electron microscope (TEM), we could see that the surfaces of PIV particles exhibited spherical and band-shaped 'tufts'; from the 3D images under AFM, we could further observe the whole spherical virus particles and their detailed surfaces, which exhibited round and band-shaped 'tufts'. Comparing the images under TEM with those under AFM, we found that the latter could reveal the surface topograph and ultramicrostructure of viruses more truly than did the former. The samples of viruses were treated by Tritonx-100, the lipid envelopes of virions were partly or completely resolved, and then most of their capsids were exposed. We could observe the different appearances of the virions under AFM, the lipid envelopes of which were gradually removed. The samples of viruses were also treated by SDS, and the RNA was released from the virions. From the AFM images, we could see the structure of the RNA. It was thus clear that AFM could be used to investigate the different appearances and ultramicrostructure of viruses rapidly and efficiently.

Viral pathogens of acute lower respiratory tract infection in China.

OBJECTIVES: To document the viral etiology of acute lower respiratory tract infection (ALRIs) in Chinese children. SETTING: Children Hospital, Zhejiang University, China. STUDY DESIGN: Cross-sectional. PARTICIPANTS: 34885 children with ALRI between January 2001 to December 2006. METHODS: Nasopharyngeal aspirates were collected from all subjects. Respiratory syncytial virus (RSV), adenovirus (ADV), type 1 to 3 parainfluenza viruses (PIV), and type A and B influenza virus (Flu) were detected by direct immunofluorescence. RESULTS: Viruses were identified in 32.3% cases, including RSV (23.6%), PIV 3 (4.3%), Flu A (2.0%), ADV (1.7%), PIV I (0.6%), Flu B (0.2%) and PIV 2 (0.1%). RSV and PIV 3 predominated in younger children while Flu A and Flu B predominated in older children (P<0.001, respectively). PIV 1 was more prevalent in children aged 1 to 3 years. The peak frequency of RSV, PIV 3 and Flu A were in early spring, June to August, and August and September, respectively. Flu B had a peak in the winter and spring. Adenovirus infections occurred in all seasons with a relatively constant frequency. CONCLUSIONS: Viruses are an important cause of ALRIs in Chinese children constituting 1/3 of total cases. RSV is the most common pathogen.

Vigilancia seroepidemiológica de los Parainfluenza virus humano (PIVh) tipos 2 y 3 en una población infantil seleccionada en Ciudad de La Habana / Seroepidemiological surveillance of human parainfluenza viruses (HPIVs) types 2 and 3 in an infantile population selected in Havana City

Se estudió la presencia de anticuerpos contra los virus Parainfluenza humanos tipos 2 y 3 en 1 793 sueros de una población infantil menor de 14 años de edad. Para el pesquisaje de las muestras clínicas se empleó como sistema la técnica de inhibición de la hemaglutinación. Del total de sueros analizados fueron positivos 1 382 (77,1 por ciento), de estos se confirmó la presencia de anticuerpos contra el tipo 2 en 320 (17,8 por ciento), para el tipo 3 en 334 (18,6 por ciento) y predominó la seropositividad simultánea en 805 (44,9 por ciento). Se constató la circulación de los virus Parainfluenza humanos durante todos los meses del año y en todos los grupos de edades analizados, con aumento en los porcentajes de positividad con la edad

An Epidemiological Study of Mycoplasmal penumoniae Pneumonia in Children from 1995 to 2004 in a Tertiary Hospital in Seoul / 소아알레르기및호흡기학회지

PURPOSE: Mycoplasma pneumoniae is the major cause of respiratory infections in school- aged children and young adults. This study aimed to investigate the epidemiological features of M. pneumoniae pneumonia in Korean children, between 1995 and 2003. METHODS: We retrospectively reviewed the medical record of 575 patients with M. pneumoniae pneumonia. In patients with pneumonia who visited Samsung Medical Center from January 1995 to December 2003, M. pneumoniae infection was confirmed by mycoplasma antibody titer > 1: 320 or four-fold increase. We analyzed age and sex distribution, monthly and annual epidemics, and mixed infection with respiratory viruses. RESULTS: The mean age was 4.49+/-2.80 years (range 0-16 years). There were 281 females and 294 males. The peak incidence was at 4 years of age (17.6 percent) and there were 333 person from 3 to 6 years of age (57.2 percent). Infants younger than 2 years accounted for 23.8 percent. M. pneumoniae pneumonia occurred mostly from September to December (64.8 percent) ; in November (18.1 percent), in December (16.2 percent), and in October (16.0 percent). Annual incidences were 9.6 percent in 1997 and 10.9 percent in 2000, 18.7 percent in 2003, respectively, while much lower incidences were noted in the other years. Seven cases showed mixed infection with respiratory viruses; adenovirus (n=3), RSV (n=2), Influenza virus (n=1), parainfluenza virus type 2 (n=1). CONCLUSION: In Seoul, Korea, epidemic outbreaks of M. pneumoniae pneumonia occurred every three years with peak incidences in the fall. These epidemiological data will be helpful for the prediction of occurrences of M. pneumoniae infection.

Prevalence of parainfluenza and influenza viruses amongst children with upper respiratory tract infection

The objective of this study was to determine the prevalence of Parainfluenza and Influenza causing upper respiratory tract infections and to evaluate shell vial culture assay and direct immunofluorescence assay. A retrospective study during the period between November 1997 and May 1998. A total of 350 nasopharyngeal aspirates were obtained from children suffering from respiratory tract infections. Nasopharyngeal aspirates were investigated for the presence of Parainfluenza 1, 2 and 3, Influenza A and B using shell vial culture assay, conventional culture assay and direct immunofluorescence assay. Parainfluenza 1 were identified in 3%, Parainfluenza 2 in 5% and Parainfluenza 3 in 6%. Influenza A were identified in 4% and Influenza B in 2%. Parainfluenza 1, 2 and 3 were isolated in children less than 5 years old. Most of Parainfluenza cases were associated with other upper respiratory infections. Shell vial assay showed a sensitivity of 90-93% and specificity of 99-100% for detecting Parainfluenza 1, 2 and 3. These results emphasize that shell vial assay is important for the diagnosis of Parainfluenza and Influenza, although direct immunofluorescence assay is the superior diagnositic assay

Clinical characteristics of acute viral lower respiratory tract infections in hospitalized children in Seoul, 1996-1998

This study was performed to investigate the etiologic agents, age distribution, clinical manifestations and seasonal occurrence of acute viral lower respiratory tract infections in children. We confirmed viral etiologies using nasopharyngeal aspirates in 237 patients of the ages of 15 years or younger who were hospitalized for acute lower respiratory tract infection (ALRI) from March 1996 to February 1998 at Samsung Seoul Hospital, Seoul, Korea. The overall isolation rate was 22.1%. The viral pathogens identified were adenovirus (12.7%), influenza virus type A (21.1%), -type B (13.9%), parainfluenza virus type 1 (13.5%), -type 2 (1.3%), -type 3 (16.0%) and respiratory syncytial virus (21.5%). The occurrence of ALRIs was highest in the first year of life, although parainfluenza virus type 1 infection occurred predominantly in the second year of life and influenza virus caused illnesses in all age groups. The specific viruses are frequently associated with specific clinical syndromes of ALRI. The respiratory agents and associated syndromes frequently have characteristic seasonal patterns. This study will help us to estimate the etiologic agents of ALRI, and establish a program for the prevention and treatment. An annual nationwide survey is necessary to understand the viral epidemiology associated with respiratory illnesses in Korea.

Laringotraqueobronquitis, CRUP Viral: controversias en la terapia

La laringotraqueobronquitis o crup viral es una de las entidades clínicas más frecuentes y clásicas de la patología respiratoria pediátrica. La presente revisión evalúa, a la luz de las más recientes publicaciones sobre el tema, el papel terapéutico de medidas como la aerosolterapia, las nebulizaciones de epinefrina racémica, adrenalina y fenilefrina, la administración parenteral de glucocorticoides y el empleo de una escala de puntaje para evaluar la severidad del compromiso del paciente y la respuesta al tratamiento.

Manejo actual de la laringotraquebronquitis en niños / Present management of the laryngel-tracheal-bronchitis in children

Las enfermedaes respiratorias infantiles constituyen la causa más frecuente de consulta al pediatra. Las características anatómicas de la vía aérea, la predisposición alérgica y las condiciones epidemiológicas hacen al niño más vulnerable al contagio con agentes virales. La laringotraqueobronquitis es una enfermedad de etiología viral y su curso normal dura aproximadamente una semana, descartando el tratamiento antibióticvo, en la mayoría de los casos. La evaluación médica es el método de disgnóstico más importante. Las medidas generales de tratamiento, como ambiente tranquilo, estímulos mínimos y reducción de estrés y dolor, son factores que favorecen la regresión espontánea de la obstrucción de la vía aérea

Laringotraqueobronquites: aspectos atuais / Laryngotracheobronchites: actuals aspects

Os autores, com base na experiência pessoal e na literatura, apresentam como se conduzem nos casos de LTB, principalmente nos graves. Abordam a incidência, etiologia, diagnóstico, tratamento e indicaçöes para intubaçäo, bem como os mecanismos de defesa do pulmäo

Laringotraqueobronquitis / Laryngotracheobronchitis

El presente estudio fué realizado en el Departamento de Pediatria del Hospital Materno Infantil Germán Urquidi, habiendose revisado 50 historias clinicas que son el total de pacientes que egresaron con diagnóstico de laringotraqueobronquitis aguda durante el periodo de 1988 hasta Diciembre de 1990. Los resultados mas relevantes son el hecho de que la mayor incidencia corresponde a los meses de Mayo, Junio y Agosto con 18, 12 por ciento y 14 por ciento respectivamente. Es patologia de Eutróficos y desnutridos de primer grado en un 82 por ciento; el 52 por ciento de los casos se presentan en horario nocturno y el tratamiento mas usado es el esquema de vapor mas oxigeno antibioticos y cortocosteroides, en las difunciones fue por cardiopatia congénita asociada y otros por complicación séptica y encefalopatia hipoxica. En un solo caso fue necesario la traqueostomía con resultado favorable posterior y otro aquien se entubo por periodos de apnéa prolongada y daño hipoxico manifiesto ya desde su ingreso, quien fallecio posteriormente, el tiempo promedio de internación fue de 3 dias.

Detección viral en infecciones respiratorias agudas del lactante / Viral detection in acute respiratory infections in infants

Los virus respiratorios se detectan en un alto porcentaje en la patología respiratoria aguda que afecta al lactante. No nos debe llamar la atención que un alto porcentaje de virus detectados aparecieron en los cuadros de Neumonitis. Es llamativo el alto porcentaje de positividad viral encontrado en las Bronconeumonias. Por último, el aumento de la detección viral observada en los últimos años se debe fundamentalmente a la introducción de nuevas técnicas, específicamente, la detección de antígenos virales por inmunofluorescencia directa y aislamiento viral a partir del aspirado nasofaríngeo y también, a la adecuada toma, envío y procesamiento de las muestras