Outbreak of Herpesviral Conjunctivitis and Respiratory Disease in Gouldian Finches

An outbreak of tracheitis, sinusitis, and conjunctivitis, originating in recently imported birds, caused high morbidity and mortality in a flock of finches in Central Illinois. Although several species were present, Gouldian finches ( Erythrura [Chloebia] gouldiae) were most commonly and severely affected. Birds submitted for necropsy displayed microscopic lesions characteristic of herpesviral infection, including epithelial cytomegaly and karyomegaly with basophilic, intranuclear inclusion bodies in the nasopharynx, sinuses, trachea, parabronchi, conjunctiva, and occasionally the lacrimal gland or proximal proventricular glands. Viral particles consistent with herpesvirus were visualized within affected epithelial cells with electron microscopy. Based on a partial sequence of the viral DNA polymerase gene, this virus was found to be identical to a herpesvirus previously implicated in a similar outbreak in Canada and is most likely an alphaherpesvirus.

Epidemiology, Genetic Recombination, and Pathogenesis of Coronaviruses

Human coronaviruses (HCoVs) were first described in the 1960s for patients with the common cold. Since then, more HCoVs have been discovered, including those that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), two pathogens that, upon infection, can cause fatal respiratory disease in humans. It was recently discovered that dromedary camels in Saudi Arabia harbor three different HCoV species, including a dominant MERS HCoV lineage that was responsible for the outbreaks in the Middle East and South Korea during 2015. In this review we aim to compare and contrast the different HCoVs with regard to epidemiology and pathogenesis, in addition to the virus evolution and recombination events which have, on occasion, resulted in outbreaks amongst humans.

Age at Vaccination and Timing of Infection Do Not Alter Vaccine-Associated Enhanced Respiratory Disease in Influenza A Virus-Infected Pigs

Whole inactivated virus (WIV) vaccines are widely used in the swine industry to reduce clinical disease against homologous influenza A virus (IAV) infection. In pigs experimentally challenged with antigenically distinct heterologous IAV of the same hemagglutinin subtype, WIV vaccinates have been shown to develop vaccine-associated enhanced respiratory disease (VAERD). We evaluated the impact of vaccine valency, age at vaccination, and duration between vaccination and challenge on the development of VAERD using vaccine containing δ1-H1N2 and challenge with pandemic H1N1 (pH1N1) virus. Pigs were vaccinated with monovalent WIV MN08 (δ1-H1N2) and bivalent (δ1-H1N2-H3N2 or δ1-H1N2-pH1N1) vaccines and then were challenged with pH1N1 at 3 weeks postboost (wpb). Another group was vaccinated with the same monovalent WIV and challenged at 6 wpb to determine if the time postvaccination plays a role in the development of VAERD. In a follow-up study, the impact of age of first WIV vaccination (at 4 versus 9 weeks of age) with a boost 3 weeks later (at 7 versus 12 weeks of age) was evaluated. A monovalent live-attenuated influenza virus (LAIV) vaccine administered at 4 and 7 weeks of age was also included. All mismatched WIV groups had significantly higher lung lesions than the LAIV, bivalent MN08-CA09, and control groups. Age of first vaccination or length of time between booster dose and subsequent challenge did not alter the development of VAERD in WIV-vaccinated pigs. Importantly, the mismatched component of the bivalent MN08-CA09 WIV did not override the protective effect of the matched vaccine component.

Global Role and Burden of Influenza in Pediatric Respiratory Hospitalizations, 1982-2012: A Systematic Analysis

BACKGROUND

The global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide.

METHODS AND FINDINGS

We aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5-17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status. Influenza was associated with 10% (95% CI 8%-11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%-7%) among children <6 mo to 16% (95% CI 14%-20%) among children 5-17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y-of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo-and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings.

CONCLUSIONS

Influenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo.

Small particle aerosol inoculation of cowpox Brighton Red in rhesus monkeys results in a severe respiratory disease

Cowpox virus (CPXV) inoculation of nonhuman primates (NHPs) has been suggested as an alternate model for smallpox (Kramski et al., 2010, PLoS One, 5, e10412). Previously, we have demonstrated that intrabronchial inoculation of CPXV-Brighton Red (CPXV-BR) into cynomolgus monkeys resulted in a disease that shared many similarities to smallpox; however, severe respiratory tract disease was observed (Smith et al., 2011, J. Gen. Virol.). Here we describe the course of disease after small particle aerosol exposure of rhesus monkeys using computed tomography (CT) to monitor respiratory disease progression. Subjects developed a severe respiratory disease that was uniformly lethal at 5.7 log10 PFU of CPXV-BR. CT indicated changes in lung architecture that correlated with changes in peripheral blood monocytes and peripheral oxygen saturation. While the small particle aerosol inoculation route does not accurately mimic human smallpox, the data suggest that CT can be used as a tool to monitor real-time disease progression for evaluation of animal models for human diseases.

Middle East respiratory syndrome coronavirus "MERS-CoV": current knowledge gaps

The Middle East respiratory syndrome coronavirus (MERS-CoV) that causes a severe lower respiratory tract infection in humans is now considered a pandemic threat to the Gulf region. Since its discovery in 2012, MERS-CoV has reached 23 countries affecting about 1100 people, including a dozen children, and claiming over 400 lives. Compared to SARS (severe acute respiratory syndrome), MERS-CoV appears to kill more people (40% versus 10%), more quickly, and is especially more severe in those with pre-existing medical conditions. Most MERS-CoV cases (>85%) reported thus far have a history of residence in, or travel to the Middle East. The current epidemiology is characterised by slow and sustained transmission with occasional sparks. The dromedary camel is the intermediate host of MERS-CoV, but the transmission cycle is not fully understood. In this current review, we have briefly summarised the latest information on the epidemiology, clinical features, diagnosis, treatment and prevention of MERS-CoV especially highlighting the knowledge gaps in its transmission dynamics, diagnosis and preventive strategy.

[Research Progress in Airway Epithelial Cell Culture as a Respiratory Disease Model]

Respiratory virus poses a serious threat to human life and health. Airway epithelial cells are the body's first line of defense from a wide variety of foreign pathogens, such as viruses and bacteria. Therefore, successful airway epithelial cell culture can provide a model for investigating the mechanisms underlying respiratory pathogenic diseases following airway virus infection. This respiratory disease model can also be used for the potential development of novel therapeutics. Here we provide a brief review of recent developments on the culture of cells derived from human trachea-bronchial airway epithelium, and the application of this model for studying respiratory virus and disease.

Discovery of a novel nidovirus in cattle with respiratory disease

The family Coronaviridae represents a diverse group of vertebrate RNA viruses, all with genomes greater than 26,000 nt. Here, we report the discovery and genetic characterization of a novel virus present in cattle with respiratory disease. Phylogenetic characterization of this virus revealed that it clusters within the subfamily Torovirinae, in the family Coronaviridae. The complete genome consists of only 20,261 nt and represents the smallest reported coronavirus genome. We identified seven ORFs, including the canonical nidovirus ORF1a and ORF1b. Analysis of polyprotein 1ab revealed that this virus, tentatively named bovine nidovirus (BoNV), shares the highest homology with the recently described python-borne nidoviruses and contains several conserved nidovirus motifs, but does not encode the NendoU or O-MT domains that are present in other viruses within the family Coronaviridae. In concert with its reduced genome, the atypical domain architecture indicates that this virus represents a unique lineage within the order Nidovirales.

[Detection of the new influenza A subtype H1pdmN2 in a pig holding with severe respiratory symptoms]

Early in 2012 fattening pigs in a pig holding in northern Baden-Württemberg developed serious respiratory disease. After detecting Influenza A specific RNA by Real time-RT-PCR in the lung of an euthanized pig, virus isolation was achieved in embryonated chicken eggs. The haemagglutination-inhibition (HI) test performed on this isolate showed a reaction with H1N1 specific serum, so the strain was initially characterised as subtype H1N1. However, serum samples from convalescent pigs of the same stock four and six weeks later did not show any antibodies to H1N1 in HI test. However, using an ELISA, selected serum samples showed positive reactions against the highly conserved nucleocapsid protein. Performing an HI test using the isolated virus as antigen, significantly positive titers between 1:80 and 1:160 were obtained. The virus isolate was finally identified by molecular methods as a subtype H1pdmN2, a reassortant between the human pandemic (pdm) subtype H1N1/2009 virus and a swine influenza virus of the subtype HxN2.

Novel respiratory viruses: what should the clinician be alert for?

Since 1990, several novel respiratory viruses affecting humans have been described. In this review, we focus on three pathogens that have caused significant human mortality and raise important public health concerns: severe acute respiratory syndrome (SARS)-coronavirus, Middle East respiratory syndrome (MERS)-coronavirus and avian influenza A viruses (H5N1 and H7N9). Novel respiratory viruses have the potential to instil fear in the public and physicians alike if they are associated with a high case fatality rate. Those viruses with a significant potential for onward human-to-human transmission (including in healthcare settings) might present significant challenges for national public health services and local hospital infection control.

Association of swine influenza H1N1 pandemic virus (SIV-H1N1p) with porcine respiratory disease complex in sows from commercial pig farms in Colombia

Porcine respiratory disease complex (PRDC) is a serious health problem that mainly affects growing and finishing pigs. PRDC is caused by a combination of viral and bacterial agents, such as porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), Mycoplasma hyopneumoniae (Myh), Actinobacillus pleuropneumoniae (APP), Pasteurella multocida and Porcine circovirus 2 (PCV2). To characterize the specific role of swine influenza virus in PRDC presentation in Colombia, 11 farms from three major production regions in Colombia were examined in this study. Nasal swabs, bronchial lavage and lung tissue samples were obtained from animals displaying symptoms compatible with SIV. Isolation of SIV was performed in 9-day embryonated chicken eggs or Madin-Darby Canine Kidney (MDCK) cells. Positive isolates, identified via the hemagglutination inhibition test, were further analyzed using PCR. Overall, 7 of the 11 farms were positive for SIV. Notably, sequencing of the gene encoding the hemagglutinin (HA) protein led to grouping of strains into circulating viruses identified during the human outbreak of 2009, classified as pandemic H1N1-2009. Serum samples from 198 gilts and multiparous sows between 2008 and 2009 were obtained to determine antibody presence of APP, Myh, PCV2 and PRRSV in both SIV-H1N1p-negative and -positive farms, but higher levels were recorded for SIV-H1N1p-positive farms. Odds ratio (OR) and P values revealed statistically significant differences (p<0.05) in PRDC presentation in gilts and multiparous sows of farms positive for SIV-H1N1p. Our findings indicate that positive farms have increased risk of PRDC presentation, in particular, PCV2, APP and Myh.

Detection and complete genome characterization of human enterovirus 118 from children with acute respiratory disease in China

Enterovirus 118 (EV-118) within species HEV-C was detected in two 5-month-old boys with pneumonia in China. The EV-118 from both cases was genetically closer to ISR10 strain from Israel than to PER161 strain from Peru based on VP1 gene sequences. The complete genome of the detected EV-118 consists of 7,360 nucleotides, excluding the poly (A) tail. The 5'UTR contains 669 nucleotides, and 3'UTR consists of 73 nucleotides. A single open reading frame from base 670 to 7,287 that encodes a 2,206-amino-acid polyprotein was featured. The base composition of the full genome is 27.9 % A, 24.2 % C, 24.4 % G, and 23.6 % U. Phylogenetic analysis of the full genome sequences illustrated EV-118 was genetically closer to EV-109 and EV-105, and the Chinese strain differed from Peru strain. In summary, the presence of EV-118 was confirmed in pediatric pneumonia cases and complete genome sequences were identified for the first time in China.

Is influenza-like illness a useful concept and an appropriate test of influenza vaccine effectiveness?

PURPOSE

To assess the utility of "influenza-like illness" (ILI) and whether it appropriately tests influenza vaccine effectiveness.

PRINCIPAL RESULTS

The WHO and CDC definitions of "influenza-like illness" are similar. However many studies use other definitions, some not specifying a temperature and requiring specific respiratory and/or systemic symptoms, making many samples non-comparable. Most ILI studies find less than 25% of cases are RT-PCR-positive, those which test for other viruses and bacteria usually find multiple other pathogens, and most identify no pathogen in about 50% of cases. ILI symptom and symptom combinations do not have high sensitivity or specificity in identifying PCR-positive influenza cases. Rapid influenza diagnostic tests are increasingly used to screen ILI cases and they have low sensitivity and high specificity when compared to RT-PCR in identifying influenza.

MAIN CONCLUSIONS

The working diagnosis of ILI presumes influenza may be involved until proven otherwise. Health care workers would benefit by renaming the WHO and CDC ILI symptoms and signs as "acute respiratory illness" and also using the WHO acute severe respiratory illness definition if the illness is severe and meets this criterion. This renaming would shift attention to identify the viral and bacterial pathogens in cases and epidemics, identify new pathogens, implement vaccination plans appropriate to the identified pathogens, and estimate workload during the viral season. Randomised controlled trials testing the effectiveness of influenza vaccine require all participants to be assessed by a gold standard (RT-PCR). ILI has no role in measuring influenza vaccine effectiveness. ILI is well established in the literature and in the operational definition of many surveillance databases and its imprecise definition may be inhibiting progress in research and treatment. The current ILI definition could with benefit be renamed "acute respiratory illness," with additional definitions for "severe acute respiratory illness" (SARI) with RT-PCR testing for pathogens to facilitate prevention and treatment.

Impact of home environment interventions on the risk of influenza-associated ARI in Andean children: observations from a prospective household-based cohort study

Background

The Respiratory Infections in Andean Peruvian Children (RESPIRA-PERU) study enrolled children who participated in a community-cluster randomized trial of improved stoves, solar water disinfection, and kitchen sinks (IHIP trial) and children from additional Andean households. We quantified the burden of influenza-associated acute respiratory illness (ARI) in this household-based cohort.

Methods

From May 2009 to September 2011, we conducted active weekly ARI surveillance in 892 children age <3 years, of whom 272 (30.5%) had participated in the IHIP trial. We collected nasal swabs during ARI, tested for influenza and other respiratory viruses by RT-PCR, and determined influenza incidence and risk factors using mixed-effects regression models.

Results

The overall incidence of influenza-associated ARI was 36.6/100 child-years; incidence of influenza A, B, and C was 20.5, 8.7, and 5.2/100 child-years, respectively. Influenza C was associated with fewer days of subjective fever (median 1 vs. 2) and malaise (median 0 vs. 2) compared to influenza A. Non-influenza ARI also resulted in fewer days of fever and malaise, and fewer healthcare visits than influenza A-associated ARI. Influenza incidence varied by calendar year (80% occurred in the 2010 season) and IHIP trial participation. Among households that participated in the IHIP trial, influenza-associated ARI incidence was significantly lower in intervention than in control households (RR 0.40, 95% CI: 0.20–0.82).

Conclusions

Influenza burden is high among Andean children. ARI associated with influenza A and B had longer symptom duration and higher healthcare utilization than influenza C-associated ARI or non-influenza ARI. Environmental community interventions may reduce influenza morbidity.

[Progress on development and research of human bocavirus 1]

Human bocavirus 1 (HBoV1) is a novel virus that mainly causes respiratory tract infection, and it has the characteristic of genome of Parvovirus, containing three open reading frames that encode non-structural proteins NS1 and NP1 and structural proteins VP1 and VP2. Circular episome is present during the rolling circle replication of HBoV1, which provides the possibility of full genome amplification and infectious clone construction to save HBoV1. The recombination between HBoV1 and HBoV2-4 occurs frequently. With the three-dimensional culture, in vitro culture of HBoV1 provides a powerful tool for research on the pathogenesis of HBoV1. This review focuses on the molecular characteristics, association with diseases, in vitro culture, diagnosis and treatment of HBoV1.

Closely related influenza viruses induce contrasting respiratory tract immunopathology

The swine-origin H1N1 virus which emerged in 2009 resulted in the first influenza pandemic of the 21^st century. Although the majority of infections were moderate, a significant proportion of infections were severe and characterized by acute respiratory distress syndrome and pulmonary edema. We compared two isolates from the 2009 H1N1 pandemic; A/California/07/09 (CA/07) and A/Netherlands/602/09 (NL/602) viruses that share greater than 99% sequence identity. Though genetically similar, these viruses exhibit contrasting pathological effects. Mice that were infected with 800 plaque forming unit (PFU) of CA/07 virus rapidly lost weight, which was concurrent with detection of high pulmonary concentrations of MCP-1, MIG, IP-10 and TIMP-1. Initially, severe bronchiolar epithelial necrosis and acute respiratory distress was observed, followed by marked bronchiolar epithelial hyperplasia. Mononuclear cell infiltration was initially localized to perivascular and peribronchiolar interstitium and then spread to adjacent alveoli. Infiltrating cells were phenotypically CD11b^hi, F4/80^lo. In contrast, when mice were infected with 800 PFU of NL/602 virus, minimal weight loss was observed, and concentrations of cytokines in the lung were significantly lower. Inflammation was primarily restricted to the bronchioles and perivascular interstitium with minimal spread to alveoli. Infiltrating cells include foamy macrophages and surface markers were characterized as CD11b^lo/-, F4/80^hi. These two genetically similar viruses can be useful strains with which to investigate immune-regulatory determinants of pathogenesis of influenza virus.

Decreased pattern recognition receptor signaling, interferon-signature, and bactericidal/permeability-increasing protein gene expression in cord blood of term low birth weight human newborns

Background

Morbidity and mortality rates of low birth weight (LBW) newborns at term are higher than rates in normal birth weight (NBW) newborns. LBW newborns are at greater risk to acquire recurrent bacterial and viral infections during their first few weeks of life possibly as an outcome of compromised innate immune functions. As adaptive immunity is in a naive state, increased risk of infection of LBW as compared to NBW newborns may reflect impairments in innate immunity.

Methodology

To characterize the increased susceptibility to infections in LBW newborns we used microarray technology to identify differences in gene expression in LBW newborns (n = 8) compared to NBW newborns (n = 4) using cord blood. The results obtained from the microarray study were validated on a larger number of samples using real time RT-PCR (LBW = 22, NBW = 18) and western blotting (LBW = 12, NBW = 12). The Interferome database was used to identify interferon (IFN) signature genes and ingenuity pathway analysis identified canonical pathways and biological functions associated with the differentially expressed genes in LBW newborns. ELISAs for IFNs and bactericidal/permeability-increasing protein were performed in both LBW and NBW newborns and in adults (LBW = 18, NBW = 18, Adults  = 8).

Principal Findings

Upon microarray analysis, we identified 1,391 differentially expressed genes, of which, 1,065 genes were down-regulated and 326 genes were up-regulated in the LBW compared to NBW newborns. Of note, 70 IFN-signature genes were found to be significantly down-regulated in LBW compared to NBW newborns. Ingenuity pathway analysis revealed pattern recognition receptors signaling including Toll-Like Receptors (TLRs) -1, -5, and -8 genes and IFN signaling as the most significantly impacted pathways. Respiratory infectious diseases were the most significantly affected bio-functions in LBW newborns.

Conclusion and Significance

Diminished PRRs, IFN-signature, and BPI gene expression raises the possibility that impairments in these pathways contribute to the susceptibility of LBW term infants to infection.

Identification of a novel human papillomavirus by metagenomic analysis of samples from patients with febrile respiratory illness

As part of a virus discovery investigation using a metagenomic approach, a highly divergent novel Human papillomavirus type was identified in pooled convenience nasal/oropharyngeal swab samples collected from patients with febrile respiratory illness. Phylogenetic analysis of the whole genome and the L1 gene reveals that the new HPV identified in this study clusters with previously described gamma papillomaviruses, sharing only 61.1% (whole genome) and 63.1% (L1) sequence identity with its closest relative in the Papillomavirus episteme (PAVE) database. This new virus was named HPV_SD2 pending official classification. The complete genome of HPV-SD2 is 7,299 bp long (36.3% G/C) and contains 7 open reading frames (L2, L1, E6, E7, E1, E2 and E4) and a non-coding long control region (LCR) between L1 and E6. The metagenomic procedures, coupled with the bioinformatic methods described herein are well suited to detect small circular genomes such as those of human papillomaviruses.

Adenovirus respiratory tract infections in Peru

Background

Currently, there is a paucity of data regarding human adenovirus (HAdv) circulation in Andean regions of South America. To address this shortcoming, we report the clinical, phylogenetic, and epidemiologic characteristics of HAdv respiratory tract infection from a large sentinel surveillance study conducted among adults and children in Peru.

Methods/Principal Findings

Oropharyngeal swabs were collected from participants visiting any of 38 participating health centers, and viral pathogens were identified by immunofluorescence assay in cell culture. In addition, molecular characterization was performed on 226 randomly selected HAdv samples. Between 2000 and 2010, a total of 26,375 participants with influenza-like illness (ILI) or severe acute respiratory infection (SARI) were enrolled in the study. HAdv infection was identified in 2.5% of cases and represented 6.2% of all viral pathogens. Co-infection with a heterologous virus was found in 15.5% of HAdv cases. HAdv infection was largely confined to children under the age of 15, representing 88.6% of HAdv cases identified. No clinical characteristics were found to significantly distinguish HAdv infection from other respiratory viruses. Geographically, HAdv infections were more common in sites from the arid coastal regions than in the jungle or highland regions. Co-circulation of subgroups B and C was observed each year between 2006 and 2010, but no clear seasonal patterns of transmission were detected.

Conclusions/Significance

HAdv accounted for a significant fraction of those presenting with ILI and SARI in Peru and tended to affect the younger population disproportionately. Longitudinal studies will help better characterize the clinical course of patients with HAdv in Peru, as well as determine the role of co-infections in the evolution of illness.

[Study of prevalence of rare and difficult to cultivate causative agents of inflammatory diseases of respiratory organs]

AIM

Study the prevalence of Mycoplasma pneumoniae, Chlamydophila pneumoniae, Chlamydophila psittaci, Legionella pneumophila, Moraxella catarrhalis, Cytomegalovirus, Herpes simplex I/II virus (HSV I/II) in individuals of various age groups with varying inflammatory broncho-pulmonary diseases.

MATERIALS AND METHODS

384 adults and 1001 children with clinically confirmed diagnoses were examined by PCR method: community-acquired pneumonia, acute bronchitis, bronchial asthma, ARD/ARVD, as well as 127 healthy children and 52 healthy adults. Sputum, smears from posterior fornix of pharynx, blood, saliva from children of the first year of life were used as material for the study.

RESULTS

Wide prevalence of M. pneumoniae and C. pneumoniae among adults and M. pneumoniae among children older than 1 year with inflammatory diseases of respiratory organs was established. C. psittaci, L. pneumophila, M. catarrhalis occurred in isolated cases in both adults and children. Active replication of herpes group viruses was detected in patients of all age groups with inflammatory broncho-pulmonary diseases, and in children Cytomegalovirus replication predominated, in adults--HSV I/II.

CONCLUSION

High frequency of prevalence of M. pneumoniae and C. pneumoniae in inflammatory diseases of respiratory tract was established, giving evidence of reasonability and necessity of examination of patients with various nosologic forms of diseases for these species of microorganisms with the aim of effective etiotropic therapy.

[Genetic diversity and evolution of the influenza C virus]

The influenza C virus is spread worldwide and causes diseases of the upper and (less frequently) lower respiratory tract in human. The virus is not pandemic, but it circulates together with pandemic influenza A and B viruses during winter months and has quite similar clinical manifestations. The influenza C virus is also encountered in animals (pigs and dogs) and is known to override the interspecific barriers oftransmssion. The immune system of mammals often fails to recognize new antigenic variants of influenza C virus, which invariably arise in nature, resulting in outbreaks of diseases, although the structure of antigens in influenza C virus in general is much more stable than those of influenza viruses A and B. Variability of genetic information in natural isolates of viruses is determined by mutations, reassortment, and recombination. However, recombination events very rarely occur in genomes of negative-strand RNA viruses, including those of influenza, and virtually have no effect on their evolution. Unambiguous explanations for this phenomenon have thus far not been proposed. There is no proof of recombination processes in the influenza C virus genome. On the contrary, reassortant viruses derived from different strains of influenza C virus frequently appear in vitro and are likely to be common in nature. The genome of influenza C virus comprises seven segments. Based on the comparison of sequences in one of its genes (HEF), six genetic or antigenic lineages of this virus can be distinguished (Yamagata/26/81, Aichi/1/81, Mississippi/80, Taylor/1233/47, Sao Paulo/378/82, and Kanagawa/1/76). However, the available genetic data show that all the seven segments of the influenza C virus genome evolve independently.

Respiratory viral pathogens associated with lower respiratory tract disease among young children in the highlands of Papua New Guinea

Background

Acute lower respiratory tract infections (ALRI) commonly result in fatal outcomes in the young children of Papua New Guinea (PNG). However, comprehensive studies of the viral aetiology of ALRI have not been conducted in PNG for almost 30 years.

Objectives

To determine the viruses associated with ALRI among children living in the PNG highlands using sensitive molecular detection techniques.

Study design

Pernasal swabs were collected routinely between 1 week and 18 months of age and also during episodes of ALRI, as part of a neonatal pneumococcal conjugate vaccine trial. A tandem multiplex real-time PCR assay was used to test for a comprehensive range of respiratory viruses in samples collected from 221 young children. Picornavirus typing was supported by DNA sequence analysis.

Results

Recognized pathogenic respiratory viruses were detected in 198/273 (73%) samples collected from children with no evidence of ALRI and 69/80 (86%) samples collected during ALRI episodes. Human rhinoviruses (HRV) species A, B and C were detected in 152 (56%) samples from non-ALRI children and 50 (63%) samples collected during ALRI episodes. Partial structural region sequences for two new species C rhinoviruses were added to the GenBank database. ALRI was associated with detection of adenovirus species B (p < 0.01) or C (p < 0.05), influenza A (p < 0.0001) or respiratory syncytial virus (p < 0.0001). Multiple viruses were detected more often during ALRI episodes (49%) than when children displayed no symptoms of ALRI (18%) (p < 0.0001).

Conclusions

The burden of infection with respiratory viruses remains significant in young children living in the PNG highlands.

[Three years surveillance of viral etiology of acute lower respiratory tract infection in children from 2007 to 2010]

OBJECTIVE

Viruses are common pathogens of acute lower respiratory tract infection (ALRTI) in children. There are few studies on consecutive monitoring of viral pathogens of ALRTI in a larger cohort during the past several years. The aim of this study was to investigate the viral pathogens of ALRTI in children of different age groups and to outline the epidemic feature of different viruses.

METHOD

(1) Totally 1914 (1281 male and 709 female) children with clinical diagnosis of ALRTI during the period of March 2007 to March 2010 were recruited into this study. These patients were hospitalized patients in department of internal medicine or outpatients in emergency department in Beijing Children's Hospital. The patients were divided into four groups, including 1072 patients < 1 year old, 326 patients 1- < 3 years old, 158 patients 3- < 6 years old, 358 patients ≥ 6 years old. One nasopharyngeal aspirate specimen was collected from each patient. Reverse transcription (RT) PCR methods were applied to detect common respiratory viruses including respiratory syncytial virus (RSV), human rhinovirus (HRV), influenza virus type A, B and C (IFA, IFB, IFC), parainfluenza virus (PIV) type 1-4, adenovirus (ADV), enterovirus (EV), human coronavirus (HCOV), human metapneumovirus (HMPV) and human bocavirus (HBOV).

RESULT

(1) The total positive rate of viruses was 70.3%. The positive rate was 83.0% (890/1072) in the group of < 1 year old, and 80.1% (261/326) in group of 1- < 3 years old, 60.8% (96/158) in group of 3- < 6 years old and 27.7% (99/358) in group of ≥ 6 years old, respectively. There was a significant difference in the positive rate among different age groups (χ² = 2213.5, P = 0.000). The top three viruses were RSV, HRV and PIV; and the positive rates were 50.9%, 36.2% and 12.0% respectively in group of < 1 year old. (2) The epidemic seasons of RSV and HRV were winter and spring, and PIV infection was epidemic in spring and summer. (3) The detection rates of 2 or more viruses were 38.2%, 36.4%, 30.2% and 15.2% in groups of < 1 year old, 1- < 3 years old, 3- < 6 years old and ≥ 6 years old, respectively. There was a significant difference in the mixed infection rate among different age groups (χ² = 1346.00, P = 0.000).

CONCLUSION

RSV, HRV and PIV were the most predominant pathogens in younger children with ALRTI. Different viral infections had different seasonal features. Mixed infections with two or more viruses were detected in substantial proportion of patients with ALRTI, but further studies are needed to explore the clinical significance of mixed infection with viruses in patients with ALRTI.

Clusters of acute respiratory illness associated with human enterovirus 68--Asia, Europe, and United States, 2008-2010

In the past 2 years, CDC has learned of several clusters of respiratory illness associated with human enterovirus 68 (HEV68), including severe disease. HEV68 is a unique enterovirus that shares epidemiologic and biologic features with human rhinoviruses (HRV). First isolated in California in 1962 from four children with bronchiolitis and pneumonia, HEV68 has been reported rarely since that time and the full spectrum of illness that it can cause is unknown. The six clusters of respiratory illness associated with HEV68 described in this report occurred in Asia, Europe, and the United States during 2008-2010. HEV68 infection was associated with respiratory illness ranging from relatively mild illness that did not require hospitalization to severe illness requiring intensive care and mechanical ventilation. Three cases, two in the Philippines and one in Japan, were fatal. In these six clusters, HEV68 disproportionately occurred among children. CDC learned of clusters of HEV68 from public health agencies requesting consultation or diagnostic assistance and from reports presented at scientific conferences. In each cluster, HEV68 was diagnosed by reverse transcription-polymerase chain reaction (RT-PCR) testing targeting the 5'-nontranslated region, followed by partial sequencing of the structural protein genes, VP4-VP2, VP1, or both, to give definitive, enterovirus type-specific information. This report highlights HEV68 as an increasingly recognized cause of respiratory illness. Clinicians should be aware of HEV68 as one of many causes of viral respiratory disease and should report clusters of unexplained respiratory illness to the appropriate public health agency.