Clinical and epidemiological characteristics of human parainfluenza virus infections of children in southern Taiwan.

BACKGROUND: Human parainfluenza viruses (HPIV) 1-4 had been analyzed as being one of the most frequent causes of hospitalizations for young children with respiratory tract illnesses. METHODS: This retrospective study was performed from children virologically confirmed as HPIV infection through throat swab or nasopharyngeal aspirates at a tertiary care university hospital, between January 2012 and December 2014. HPIV4 was not checked and analyzed, due to not include in the commercial kit. The demographic, epidemiological, clinical presentations, diagnosis, treatment, outcomes, and laboratory data were analyzed. RESULTS: Totally 398 cases were enrolled, including 39 (9.8%) of HPIV1, 67 (16.8%) of HPIV2, and 292 (73.4%) of HPIV3. The mean age of HPIV-infected children was 2.9 year-old, and 50.5% were among one to three year-old. A total of 56.8% HPIV3-infected children were among one to three years old, however, no HPIV2-infected children was younger than one year-old. The HPIV1-infected patients were more common to develop wheezing and diagnose as acute bronchiolitis. HPIV2-infected children were more likely to have hoarseness (23.9%), and were associated with croup (25.4%). HPIV3 was isolated from two fatal cases, with neurological underlying diseases. CONCLUSION: The impact caused by HPIVs infections is significant in hospitalized children. In the current study, our results contribute to the epidemiologic, clinical and laboratory information of HPIV infection in children in the important areas of respiratory tract infection that could support the development of optimization management.

Use of laboratory and administrative data to understand the potential impact of human parainfluenza virus 4 on cases of bronchiolitis, croup, and pneumonia in Alberta, Canada.

BACKGROUND: Human Parainfluenza Virus (hPIV) causes severe respiratory illness in infants and adults. Our study describes the association of hPIV1-4 with bronchiolitis, croup, and pneumonia using retrospective laboratory, administrative and public health data. Due to issues including the historic lack of hPIV4 in some commercial respiratory virus panels, the description of the impact of hPIV4 on croup, bronchiolitis, and pneumonia at population levels has often been limited. This study will use routine clinical laboratory data, and administrative data to provide a preliminary description of the impact of hPIV4 on these diseases in our population. METHODS: A three year cohort of patients positive for hPIV was linked with data from physician visits and hospital admissions to define cases and hospitalization status. International Classification of Disease (ICD-9) codes were used to determine if cases had croup, bronchiolitis, and pneumonia. We also looked at differences in hospitalization status, age and gender among hPIV1-4. All statistical analysis was done using SPSS (Version 19.0.0, IBM Corp© 2010) and Graphpad Prism V6 (GraphPad Software, Inc., 2012). RESULTS: Only hPIV1 and hPIV4 specimens had positivity rates greater than 5 % of all specimens sent for respiratory virus panel testing. hPIV1 exhibited a biennial pattern while the pattern for hPIV3 was less interpretable due to lower positivity rates. Circulation patterns for hPIV2 and hPIV4 were not assessed due to the low positivity rates of theses specimens. From 2010 to 2013, there were 2300 hPIV cases with hPIV3 (46 %) being the most common, followed by hPIV1 (27 %), hPIV4 (16 %) and hPIV2 (11 %). The median age was 2 years for all hPIV types. Males were slightly greater than females for hPIV1 and hPIV2, with an equal distribution for hPIV3 and slightly more females than males for hPIV4. hPIV1 and hPIV2 had the highest or proportion of croup while hPIV3 and hPIV4 had the highest proportion of pneumonia. Within hPIV4 cases, distributions of diseases were; pneumonia (21 %, 95 % CI 17.1-25.7), bronchiolitis (18 %, 95 % CI 14.3-22.5), croup (2 %, 95 % CI 0.8-3.9), mixed illness of any of pneumonia, bronchiolitis or croup (4 %, 95 % CI 2.5-7.0) or other respiratory diseases (54 %, 95 % CI 49.1-59.6). CONCLUSIONS: We used laboratory and administrative data to undertake a descriptive analysis of the association of hPIV1-4 with croup, bronchiolitis and pneumonia. hPIV4 appears to be more associated more with bronchiolitis and pneumonia and less with croup in our population.

Human parainfluenza virus type 2 V protein inhibits and antagonizes tetherin.

Tetherin (BST-2/CD317/HM1.24) is an antiviral membrane protein that prevents the release of enveloped viruses from the cell surface. We found that the growth of human parainfluenza virus type 2 (hPIV-2), but not that of V protein-deficient recombinant hPIV-2, was inhibited by tetherin. V protein immunoprecipitates with tetherin, and this interaction requires its C-terminal Trp residues. The glycosyl phosphatidylinositol attachment signal of tetherin, but not its cytoplasmic tail, was necessary for its binding with V. The distribution of the V protein clearly changed when co-expressed with tetherin in plasmid-transfected cells. hPIV-2 infection of HeLa cells reduced cell surface tetherin without affecting total cellular tetherin. This reduction also occurred in HeLa cells constitutively expressing V, whereas mutated V protein did not affect the cell surface tetherin. Our results suggest that hPIV-2 V protein antagonizes tetherin by binding it and reducing its presence at the cell surface.

Clinical and epidemiological characteristics of acute respiratory virus infections in Vietnamese children.

Information about viral acute respiratory infections (ARIs) is essential for prevention, diagnosis and treatment, but it is limited in tropical developing countries. This study described the clinical and epidemiological characteristics of ARIs in children hospitalized in Vietnam. Nasopharyngeal samples were collected from children with ARIs at Ho Chi Minh City Children's Hospital 2 between April 2010 and May 2011 in order to detect respiratory viruses by polymerase chain reaction. Viruses were found in 64% of 1082 patients, with 12% being co-infections. The leading detected viruses were human rhinovirus (HRV; 30%), respiratory syncytial virus (RSV; 23·8%), and human bocavirus (HBoV; 7·2%). HRV was detected all year round, while RSV epidemics occurred mainly in the rainy season. Influenza A (FluA) was found in both seasons. The other viruses were predominant in the dry season. HRV was identified in children of all age groups. RSV, parainfluenza virus (PIV) 1, PIV3 and HBoV, and FluA were detected predominantly in children aged 24 months, respectively. Significant associations were found between PIV1 with croup (P < 0·005) and RSV with bronchiolitis (P < 0·005). HBoV and HRV were associated with hypoxia (P < 0·05) and RSV with retraction (P < 0·05). HRV, RSV, and HBoV were detected most frequently and they may increase the severity of ARIs in children.

Viral etiologies of infant bronchiolitis, croup and upper respiratory illness during 4 consecutive years.

BACKGROUND: Prospective data on viral etiology and clinical characteristics of bronchiolitis and upper respiratory illness (URI) in infants are limited. METHODS: This prospective cohort enrolled previously healthy term infants during inpatient or outpatient visits for acute URI or bronchiolitis during September to May 2004 to 2008. Illness severity was determined using an ordinal bronchiolitis severity score. Common respiratory viruses were identified by real-time reverse-transcriptase polymerase chain reaction. RESULTS: Of 648 infants, 67% were enrolled during inpatient visits and 33% during outpatient visits. Seventy percent had bronchiolitis, 3% croup and 27% URI. Among infants with bronchiolitis, 76% had respiratory syncytial virus (RSV), 18% human rhinovirus (HRV), 10% influenza, 2% coronavirus, 3% human metapneumovirus and 1% parainfluenza virus. Among infants with croup, 39% had HRV, 28% parainfluenza virus, 28% RSV, 11% influenza, 6% coronavirus and none human metapneumovirus. Among infants with URI, 46% had HRV, 14% RSV, 12% influenza, 7% coronavirus, 6% parainfluenza virus and 4% human metapneumovirus. Individual viruses exhibited distinct seasonal, demographic and clinical expression. CONCLUSIONS: The most common infections among infants seeking care in unscheduled medical visits for URI or bronchiolitis were RSV and HRV. Demographic differences were observed between patients with different viruses, suggesting that host and viral factors play a role in phenotypic expression of viral illness.

Pathogenesis of acute respiratory illness caused by human parainfluenza viruses.

Human parainfluenza viruses (HPIVs) are a common cause of acute respiratory illness throughout life. Infants, children, and the immunocompromised are the most likely to develop severe disease. HPIV1 and HPIV2 are best known to cause croup while HPIV3 is a common cause of bronchiolitis and pneumonia. HPIVs replicate productively in respiratory epithelial cells and do not spread systemically unless the host is severely immunocompromised. Molecular studies have delineated how HPIVs evade and block cellular innate immune responses to permit efficient replication, local spread, and host-to-host transmission. Studies using ex vivo human airway epithelium have focused on virus tropism, cellular pathology and the epithelial inflammatory response, elucidating how events early in infection shape the adaptive immune response and disease outcome.

Acute bronchiolitis and croup.

Croup and acute bronchiolitis are common forms of virally induced respiratory disease in infancy and early childhood. There is good evidence that corticosteroids can ameliorate disease severity and alter the natural history of symptoms in patients who have croup and that temporary symptomatic benefit can be obtained from the use of nebulized adrenaline. The principle weakness when reviewing therapeutic interventions for acute bronchiolitis is the lack of a clear diagnostic test or definition. Current evidence suggests that oxygen is the only useful pharmacologic agent for correcting hypoxia.

Severe parainfluenza virus type 2 supraglottitis in an immunocompetent adult host: an unusual cause of a paramyxoviridae viral infection.

Parainfluenza virus is a major cause of respiratory illness in humans, manifesting from mild upper respiratory tract infection to bronchiolitis and pneumonia, especially in children. We report - to our knowledge - the first case of a nonimmunocompromised adult patient with human parainfluenza type 2 supraglottitis immediately after returning from China.

The viral aetiology of croup and recurrent croup.

BACKGROUND: Historically croup was subdivided into classic "viral" croup with associated viral upper respiratory tract infections, and recurrent or spasmodic croup where asthma and allergies were thought more important. METHODS: All children admitted to the University Hospital of Wales with croup in 2003 were eligible. Baseline demographics including croup score were recorded and per-nasal swabs taken for virus detection by RT-PCR. Recurrent croup was defined as at least one other admission for croup in the preceding or following 3 years. RESULTS: Sixty (29.4%) children entered the study, and a viral pathogen was detected in 41 (68%). There was no significant difference in the rate of virus detection between those with single episode croup and recurrent croup. CONCLUSIONS: The aetiologies of viral and recurrent croup appear similar.

Respiratory viruses in laryngeal croup of young children.

OBJECTIVES: To determine the viral cause of laryngeal croup by use of highly sensitive methods, and including recently recognized viruses in the analysis. STUDY DESIGN: One hundred forty-four consecutive children with hoarse voice and inspiratory stridor attending the emergency department were enrolled. Age- and season-matched children presenting with a wheezing illness served as control subjects (n = 76). Nasopharyngeal swabs were analyzed by polymerase chain reaction for rhinovirus and enterovirus, coronavirus, respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza A and B virus, human bocavirus, human metapneumovirus, adenovirus, and Mycoplasma pneumoniae. RESULTS: Virus infection was documented in 80% of patients with croup and 71% of control subjects. Children with croup had significantly more positive test results for PIV 1 and 2 (31% vs 4% and 6% vs 0%, respectively) and significantly fewer positive test results for RSV (15% vs 28%) than wheezing children. Rhinoviruses and enteroviruses were present equally in both groups (21% vs 25%). There was no significant difference in the frequency of influenza A virus or human bocavirus. Few subjects with adenovirus or M. pneumoniae were detected. CONCLUSION: Acute laryngeal croup is most often associated with PIV, RSV, rhinovirus, and enterovirus. Rhinovirus and enterovirus appeared equally often in croup and in wheezing illness. During late fall, they were found in 39% and 40%, respectively, of the tested samples.

Epiglottitis and croup.

Infections of the upper airways are a frequent cause of morbidity in children. Viral laryngotracheobronchitis (croup) is the most common cause of stridor in children and usually has a self-limited course with occasional relapses in early childhood. Epiglottitis has become rare in developed countries with the advent of universal vaccinations against Haemophilus influenzae. It can be rapidly fatal, however, if not promptly recognized and appropriately managed. This article reviews the pathogenesis, epidemiology, clinical presentation, diagnosis, and management of these pediatric upper airway infections.

Detection of human bocavirus in Canadian children in a 1-year study.

Human bocavirus was detected by PCR in 65 (5.1%) of 1,265 respiratory specimens collected in 2002 and 2003 from the Stollery Children's Hospital from children <17 years of age. The spectrum of illness included upper respiratory infection, croup, bronchiolitis, and pneumonia with a prominence of cough and fever.

Human Coronavirus-NL63 infections in Korean children, 2004-2006.

BACKGROUND: Human coronavirus-NL63 (HCoV-NL63) has been isolated from children with respiratory tract infections and its prevalence in Korea has not been reported. OBJECTIVES: This study was designed to investigate the presence and the clinical features of HCoV-NL63 during two winter seasons. STUDY DESIGN: During April 2004-April 2006, nasopharyngeal specimens from children hospitalized with acute respiratory disease were tested for common respiratory viruses, including RSV, influenza A, influenza B, parainfluenza viruses, and adenovirus by IFA. hMPV infection was excluded by nested RT-PCR using primers for F-gene. To detect HCoV-NL63, previously described nested PCR assays for 1a and 1b were used. PCR products of the 1a gene for HCoV-NL63 were sequenced. RESULTS: Out of 872 nasopharyngeal aspirate from children aged under 16 years, 14 (1.7%) were positive for HCoV-NL63. Most of the patients had croup (64.2%) or bronchiolitis (21.4%). The peak prevalence was found in November (28.5%). Most were collected between November 2004 and February 2005. CONCLUSIONS: HCoV-NL63 may be one of the causative agents of acute respiratory tract infection, especially croup.

Changing epidemiology of life-threatening upper airway infections: the reemergence of bacterial tracheitis.

OBJECTIVE: As a consequence of evolving medical practice, the epidemiology of potentially life-threatening upper airway infections is changing. We report our experience over 9 years with viral croup, epiglottitis, and bacterial tracheitis. PATIENTS AND METHODS: We studied a retrospective case series of patients admitted to Vermont Children's Hospital with potentially life-threatening upper airway infections viral croup, epiglottitis, or bacterial tracheitis between 1997 and 2006. MEASUREMENT AND MAIN RESULTS: There were 107 patients with viral croup admitted to Vermont Children's Hospital, with 16 (15%) admitted to the pediatric intensive care unit. Three patients with croup (17% of pediatric intensive care unit admissions, 3% of total admissions) required intubation. There were no serious complications. Eighteen patients were admitted with bacterial tracheitis. Ninety-four percent (n = 17) were admitted to the pediatric intensive care unit. Eighty-three percent (n = 15) were intubated. Twenty-eight percent of patients (n = 5) developed serious complications. Two adolescent patients were admitted with epiglottitis. Both were intubated and recovered without complications. Of 35 patients admitted to the pediatric intensive care unit with these potentially life-threatening upper airway infections, 20 patients (57%) developed respiratory failure. Fifteen patients (75%) had bacterial tracheitis, 3 patients (15%) had viral croup, and 2 patients (10%) had nonclassic epiglottitis. CONCLUSIONS: Immunization against Haemophilus influenza type b and widespread use of corticosteroids for the treatment of viral croup have changed the epidemiology of acute infectious upper airway disease. As potentially life-threatening infections, viral croup and epiglottitis have been eclipsed by bacterial tracheitis. In this series, bacterial tracheitis was 3 times more likely to have caused respiratory failure than viral croup and epiglottitis combined. Bacterial tracheitis should be considered in children who present with acute life-threatening upper airway infection.

Oral betamethasone versus intramuscular dexamethasone for the treatment of mild to moderate viral croup: a prospective, randomized trial.

OBJECTIVE: Intramuscular dexamethasone is an effective, but painful, treatment for croup. The effectiveness of betamethasone, an oral, palatable, and equally potent glucocorticoid has not been studied. The purpose of this study was to compare the effectiveness of a single oral dose of betamethasone with intramuscular dexamethasone in the outpatient treatment of mild to moderate croup. METHODS: Children aged 6 months to 6 years presenting to a tertiary care pediatric emergency department (ED) with a modified Westley croup score of 0 to 11 were randomized to receive either 0.6 mg/kg IM dexamethasone or 0.4 mg/kg PO betamethasone. Croup score, heart rate, respiratory rate, pulse oximetry, and need for supplemental treatments were recorded at study entry and at 1, 2, and 4 hours after treatment. Follow-up data were collected by daily telephone follow-up on persistence of symptoms and the need for additional treatment or physician visits up to 7 days after the ED visit. RESULTS: Each study group contained 26 patients. Despite randomization, the mean baseline croup score was higher in the dexamethasone group (3.6 +/- 2.6 vs. 2.0 +/- 2.4, P = 0.03). Patients in both groups showed a significant reduction in the croup score after treatment, and there were no significant differences between croup scores at 4 hours (P = 0.18). Similarly, there were no differences between groups in the hospital admission rate, time to resolution of symptoms, need for additional treatments, or number of return ED visits. CONCLUSION: There is no difference between oral betamethasone and intramuscular dexamethasonein the management of mild to moderate viral croup. It is palatable and does not require a nurse for administration, making it a good alternative for ambulatory management.

The assessment and management of croup.

The treatment of croup has changed considerably over the last 25 years with the liberalisation of the use of systemic corticosteroids for mild to moderate croup. The administration of corticosteroids in croup has reduced the severity of the condition, dramatically reduced the need for endotracheal intubation, shortened the duration of intubation, reduced the length of hospital stay, reduced the need for hospital admission and reduced daycare/preschool absenteeism and improved sleep in milder cases. Despite studies showing the efficacy of nebulised and intramuscular corticosteroids, the use of oral corticosteroids remains the recommended option in most, if not all, cases of croup presenting for medical assessment.

[Case report: prolonged croup due to herpes simplex infection]. / Sjúkratilfelli: Langdregin barkabólga í kjölfar herpes simplex sýkingar.

In recent years only a few cases of croup due to herpes simplex infection among healthy children have been reported. This case report concerns a 15 month old, healthy boy who was admitted to the Children's Hospital with croup and failed to recover within the week. The boy had a positive throat culture for herpes simplex type 1 and was diagnosed with croup due to herpes simplex on the basis of serology. The boy was treated with corticosteroids; a recognised practice in severe cases of croup. The harmful effects of corticosteroids in herpes simplex croup, if indeed any, are not known. We surmise that in this case the use of corticosteroids was not a decisive factor, but it has been previously noted that prolonged corticosteroid treatment can play a role in herpes simplex infection. Furthermore it has been debated whether other viral pathogens proceed the infection, but in this case serology indicates otherwise.