Human Metapneumovirus In Children Research Articles

Human Metapneumovirus Infections during COVID-19 Pandemic, Spain.

We describe an unusual outbreak of respiratory infections caused by human metapneumovirus in children during the sixth wave of COVID-19 in Spain, associated with the Omicron variant. Patients in this outbreak were older than usual and showed more hypoxia and pneumonia, longer length of stay, and greater need for intensive care.

Clinical characteristics and molecular epidemiology of human metapneumovirus in children with acute lower respiratory tract infections in China, 2017 to 2019: A multicentre prospective observational study.

Human metapneumovirus (HMPV) infection is one of the leading causes of hospitalization in young children with acute respiratory illness. In this study, we prospectively collected respiratory tract samples from children who were hospitalized with acute lower respiratory tract infection in six hospitals in China from 2017 to 2019. HMPV was detected in 145 out of 2733 samples (5.3%) from the hospitalized children. The majority of HMPV-positive children were under the age of two (67.6%), with a median age of one year. HMPV can independently cause acute lower respiratory tract infection in young children, while all patients showed mild clinical symptoms. Of all the co-infected patients, HMPV was most commonly detected with enterovirus (EV) or rhinovirus (RhV) (38.0%, followed by respiratory syncytial virus (RSV) (32.0%). The highest detection rate occurred from March to May in both northern and southern China. Out of 145 HMPV positive samples, 48 were successfully typed, of which 36 strains were subgrouped into subtypes A2c (75%), eight strains were included in subtype B1 (16.7%), and four strains were included in subtype B2 (8.3%). Moreover, 16 A2c strains contained 111-nucleotide duplications in the G gene. Twenty-seven complete HMPV genomes were successfully obtained, and 25 (92.6%) strains belonged to subtype A2c, whereas one strain was included in subgroup B1 and another was included in subgroup B2. A total of 277 mutations were observed in the complete genomes of 25 A2c strains. All results presented here improve our understanding of clinical characteristics and molecular epidemiology of HMPV infection in children.

Epidemiology and genetic characterization of human metapneumovirus in pediatric patients from Hangzhou China.

Human metapneumovirus (HMPV), which is distributed worldwide, is a significant viral respiratory pathogen responsible for causing acute respiratory tract infections (ARTIs) in children. The aim of the present study was to investigate the epidemiological and genetic characteristics of HMPV in pediatric patients in Hangzhou China following the peak of onset of coronavirus disease 2019 (COVID-19). A total of 1442 throat swabs were collected from the pediatric patients with a diagnosis of ARTI from November 2020 to March 2021. The following viruses were detected by real-time polymerase chain reaction analysis: HMPV, RSV, adenovirus, hPIV1-3, influenza A, and influenza B. A two-step method was used to amplify the F genes of the HMPV-positive samples. Following sequencing, phylogenetic analyses were conducted using the MEGA version 7 software package. Among the 1442 samples, 103 (7.14%) were positive for HMPV. No significant differences were observed in the gender distribution. The highest incidence of HMPV occurred in children older than 6 years and the lowest was noted in children younger than 6 months. Lower respiratory tract infections were diagnosed at a higher rate than upper respiratory tract infections in HMPV-infected children. Only 10 HMPV-infected children (5.41%) were inpatients compared with 93 outpatients (7.39%). Co-infection was observed in 31 HMPV-positive samples including 24 samples of double infection and seven samples of triple infection. A total of 61F gene fragments of HMPV, which were approximately 727 bp in length were successfully sequenced. All the HMPVs belonged to the genotype B and were clustered into subgenotypes B1 (1.6%, 1/61) and B2 (98.4%, 60/61). A total of four specific amino acid substitutions were noted as follows: aa280, aa296, aa392, and aa396. These substitutions were present between sequences derived from the subgenotypes B1 and B2 in the fusion open reading frame from position 244 to 429. In conclusion, the present study provided significant information regarding the epidemiological and genetic characteristics of HMPV in children living in Hangzhou. Following the first peak of the COVID-19 pandemic, HMPV was considered an important viral respiratory pathogen present in children with ARTI.

Molecular epidemiological surveillance of viral agents of acute lower respiratory tract infections in children in Accra, Ghana

BackgroundAcute lower respiratory tract infection (ALRTI) in children under 5 years is known to be predominantly caused by respiratory syncytial virus (RSV). In recent times, however, human metapneumovirus (HMPV) has also been implicated. This study sought to investigate and genotype respiratory syncytial virus and human metapneumovirus in children presenting with ALRTIs infection at the Princess Marie Louis Children’s Hospital in Accra, Ghana.MethodsChildren below 5 years who were clinically diagnosed of ALRTI and on admission at the study site were recruited between September 2015 and November 2016 for this study. Demographic data information was obtained by means of a standardized questionnaire; and relevant clinical information was obtained from medical records. Nasopharyngeal swabs were collected from 176 children recruited for the study. Ribonucleic acid was extracted from swabs and cDNA syntheses were performed by RT-PCR. RSV-positive amplicons were sequenced and analyzed for genotype assignment.ResultsRSV and HMPV prevalence among the sampled subjects were 11.4 and 1.7% respectively. Of the RSV positives, 8/20 (40%) were RSV-A and 12/20 (60%) were RSV-B. The highest prevalence was observed in children less than 12 months old. Phylogenetic analysis of the second hypervariable region of the RSV G-gene revealed that all RSV group A viruses belonged to the “novel” ON1 genotype containing the 72-nucleotide duplication; and RSV group B viruses belong to the BA IX genotype.ConclusionRSV is frequently detected in children aged under 5 years admitted with ALRTI in Ghana. Continued surveillance of viral aetiological agents is warranted to elucidate the prevalence and transmission patterns of viral pathogens that cause respiratory tract infections among children. This will help inform appropriate intervention approaches.

Molecular investigation of human metapneumovirus in children with acute respiratory infections in Chennai, South India, from 2016-2018.

Human metapneumovirus (hMPV) has emerged as a frequent cause of acute respiratory infections (ARI) among young children. The prevalence and genetic diversity of hMPV circulating in Chennai, Southern India, has not been studied yet. Hence, this study was aimed to investigate the prevalence, co-infection with other respiratory viruses like HRSV A and B, influenza A and B, hRV and HPIV 1-4 viruses, socio-demographic associations, and genotypes of hMPV among children in Chennai. A total of 350 nasal swab specimens were collected from children with ARI during April 2016 to August 2018 and tested for hMPV by real time PCR method. In this study, hMPV was detected in 4% (14/350) of the samples. One hMPV positive sample was found to be co-infected with influenza B virus. The mean and median ages of the children with hMPV infection were 61.5months (5.1years) and 83months (6.9years), respectively. Phylogenetic analysis of the partial F gene revealed the presence of A2c subcluster among the study strains as well as with B1 and B2 lineages. The prevalence data obtained in this study is important in evaluating the role of hMPV in childhood ARI and emphasizes the importance of routine viral diagnosis in hospitals. To the best of our knowledge, this is the first study to report the prevalence, seasonality, and genetic diversity of hMPV in Chennai as well as the first study to report A2c subcluster of hMPV among children in India.

Human bocavirus and human metapneumovirus in children with lower respiratory tract infections: Effects on clinical, microbiological features and disease severity .

We aimed to compare the clinical findings of human bocavirus (HBoV) and human metapneumovirus (HMPV) infections, and to analyze the effects of coinfections on clinical features and disease severity in children with HBoV and HMPV infections. Data were collected from 125 children with lower respiratory tract infections due to HBoV or HMPV, detected from nasal swap by real-time polymerase chain reaction (PCR) during the period from January, 2013 to December, 2017. In total, there were 101 HBoV (group 1) and 23 HMPV (group 2) infections in our data. The patients were further divided into four subgroups according to the coinfection status: HoBV only (subgroup 1, n = 41), HMPV only (subgroup 2, n = 19), HBoV and coinfection with other respiratory viruses (subgroup 3, n = 60), and HMPV and coinfection with other respiratory viruses (subgroup 4, n = 4). The majority (88.8%) of the patients were aged 5 years or younger. Coinfections with other respiratory viruses were significantly more common in group 1 (P = 0.001). Among patients who had nosocomial pneumonia, patients with HBoV infections had significantly longer mean length of hospital stay (LOS) than those with HMPV infections (P = 0.032). The hospitalization and antibiotic requirements were significantly higher in subgroup 1 than subgroup 3 (P = 0.005, 0.039, resp.) According to the logistic regression analyses, the LOS increased by 21.7 times with HBoV infections (P = 0.006). Human bocavirus and HMPV infections are serious pathogens mostly seen in children and usually requiring hospitalization regardless of co-infection status. The HBoV infections caused longer LOS than the HMPV infections in patients with nosocomial infections.

Seasonal distribution and phylogenetic analysis of human metapneumovirus in children with acute respiratory tract infections admitted to a general hospital in Sri Lanka

The Sri Lankan Journal of Infectious Diseases (SLJID) is an open access, peer-reviewed, biannual journal published by the Sri Lankan Society for Microbiology (SSM). The Journal considers articles from all professional disciplines involved in the field of infectious diseases. The Journal has been in publication since 2011, is included in the DOAJ since 2018 and is a member of COPE since 2021. The SLJID practices a double-blind peer review policy. From 2022, the SLJID publishes accepted manuscripts online immediately after copy-editing, enabling rapid dissemination of scientific knowledge. The published articles are subsequently compiled into two issues in April and October. The SLJID does not charge any article processing or publication fee.

Epidemiology and genotypic diversity of human metapneumovirus in paediatric patients with acute respiratory infection in Beijing, China

BackgroundAcute respiratory tract infections (ARTIs) causes high amounts of morbidity and mortality worldwide every year. Human metapneumovirus (HMPV) is a major pathogen of ARTIs in children. In this study, we aimed to investigate the epidemiology and genotypic diversity of HMPV in children hospitalized with ARTIs in Beijing, China.MethodsHospitalized children aged < 14 years with ARTIs were enrolled from April 2017 to March 2018; nasopharyngeal aspirates were collected and subjected to real-time polymerase chain reaction tests for HMPV. HMPV-positive samples were genotyped based on a partial N gene. Whole genome sequences were determined for samples with high viral loads.Results4.08% (52/1276) enrolled paediatric patients were identified as having HMPV infection. The epidemic season is winter and early spring, children aged ≤ 4 years were more susceptible to HMPV infection (47/52, 90.38%). The co-infection rate were 36.54% (19/52), the most common co-infected virus were influenza and respiratory syncytial virus. The main diagnoses of HMPV infection were pneumonia (29/52, 55.77%) and bronchitis (23/52, 44.23%), while the main clinical manifestations were cough, fever, rhinorrhoea, and sneeze. Among 48 HMPV-positive specimens, A2b (19/48, 39.58%) and B1 (26/48, 54.17%) were the main epidemic subtypes. Patients with HMPV genotype A infection had a higher viral load compared to genotype B patients (6.07 vs. 5.37 log10 RNA copies/ml). Five complete sequences of HMPV were obtained. This is the first report of a whole genome sequence of HMPV-B1 isolated in China.ConclusionsHMPV is an important respiratory pathogen in paediatric patients. Cases of HMPV infection could burden hospitals in the epidemic season. HMPV viral loads and genotypes have no correlation with co-infection or clinical characteristics.

Global burden of acute lower respiratory infection associated with human metapneumovirus in children under 5 years in 2018: a systematic review and modelling study

SummaryBackgroundHuman metapneumovirus is a common virus associated with acute lower respiratory infections (ALRIs) in children. No global burden estimates are available for ALRIs associated with human metapneumovirus in children, and no licensed vaccines or drugs exist for human metapneumovirus infections. We aimed to estimate the age-stratified human metapneumovirus-associated ALRI global incidence, hospital admissions, and mortality burden in children younger than 5 years.MethodsWe estimated the global burden of human metapneumovirus-associated ALRIs in children younger than 5 years from a systematic review of 119 studies published between Jan 1, 2001, and Dec 31, 2019, and a further 40 high quality unpublished studies. We assessed risk of bias using a modified Newcastle-Ottawa Scale. We estimated incidence, hospital admission rates, and in-hospital case-fatality ratios (hCFRs) of human metapneumovirus-associated ALRI using a generalised linear mixed model. We applied incidence and hospital admission rates of human metapneumovirus–associated ALRI to population estimates to yield the morbidity burden estimates by age bands and World Bank income levels. We also estimated human metapneumovirus-associated ALRI in-hospital deaths and overall human metapneumovirus-associated ALRI deaths (both in-hospital and non-hospital deaths). Additionally, we estimated human metapneumovirus-attributable ALRI cases, hospital admissions, and deaths by combining human metapneumovirus-associated burden estimates and attributable fractions of human metapneumovirus in laboratory-confirmed human metapneumovirus cases and deaths.FindingsIn 2018, among children younger than 5 years globally, there were an estimated 14·2 million human metapneumovirus-associated ALRI cases (uncertainty range [UR] 10·2 million to 20·1 million), 643 000 human metapneumovirus-associated hospital admissions (UR 425 000 to 977 000), 7700 human metapneumovirus-associated in-hospital deaths (2600 to 48 800), and 16 100 overall (hospital and community) human metapneumovirus-associated ALRI deaths (5700 to 88 000). An estimated 11·1 million ALRI cases (UR 8·0 million to 15·7 million), 502 000 ALRI hospital admissions (UR 332 000 to 762 000), and 11 300 ALRI deaths (4000 to 61 600) could be causally attributed to human metapneumovirus in 2018. Around 58% of the hospital admissions were in infants under 12 months, and 64% of in-hospital deaths occurred in infants younger than 6 months, of which 79% occurred in low-income and lower-middle-income countries.InterpretationInfants younger than 1 year have disproportionately high risks of severe human metapneumovirus infections across all World Bank income regions and all child mortality settings, similar to respiratory syncytial virus and influenza virus. Infants younger than 6 months in low-income and lower-middle-income countries are at greater risk of death from human metapneumovirus-associated ALRI than older children and those in upper-middle-income and high-income countries. Our mortality estimates demonstrate the importance of intervention strategies for infants across all settings, and warrant continued efforts to improve the outcome of human metapneumovirus-associated ALRI among young infants in low-income and lower-middle-income countries.FundingBill & Melinda Gates Foundation.

High prevalence of SARS-CoV-2 and influenza A virus (H1N1) coinfection in dead patients in Northeastern Iran.

In the last months of 2019, an outbreak of fatal respiratory disease started in Wuhan, China, and quickly spread to other parts of the world. It was named COVID-19, and to date, thousands of cases of infection and death are reported worldwide. This disease is associated with a wide range of symptoms, which makesaccuratediagnosis of it difficult. During previous severe acute respiratory syndrome (SARS) pandemic in 2003, researchers found that the patients with fever, cough, or sore throat had a 5% influenza virus-positive rate. This finding made us think that the wide range of symptoms and also relatively high prevalence of death in our patients may be due to the coinfection with other viruses. Thus, we evaluated the coinfection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with other respiratory viruses in dead patients in North Khorasan. We evaluated the presence of influenza A/B virus, human metapneumovirus, bocavirus, adenovirus, respiratory syncytial virus (RSV), and parainfluenza viruses in 105 SARS-CoV-2 positive dead patients, using polymerase chain reaction (PCR) and reverse transcription PCR tests. We found coinfection with influenza virus in 22.3%, RSV, and bocavirus in 9.7%, parainfluenza viruses in 3.9%, human metapneumovirus in 2.9%, and finally adenovirus in 1.9% of SARS-CoV-2 positive dead cases. Our findings highlight a high prevalence of coinfection with influenza A virus and the monopoly of coinfection with Human metapneumovirus in children.

Prevalence, clinical outcomes and rainfall association of acute respiratory infection by human metapneumovirus in children in Bogot\xe1, Colombia

BackgroundAcute respiratory infections (ARIs) are one of the main causes of morbidity and mortality in children. Viruses are the main etiological agents, and their behavior tends to be seasonal and vary by geographical location. Human metapneumovirus (HMPV) has recently been described as a cause of severe acute respiratory infection and its prevalence and clinical behavior in children at moderate altitudes is unknown.MethodsA cross-sectional study was carried out on patients seen at a university hospital in Bogotá, Colombia between October 2015 and December 2017 in a city at a moderate altitude above sea level. Children with acute respiratory infections who had had a multiplex RT-PCR assay were selected. The prevalence of HMPV infection, its clinical outcomes and its relationship to rainfall were evaluated.ResultsOut of a total of 14,760 discharged patients, multiplex RT-PCR was performed on 502 and a virus was detected in 420 children with acute respiratory infection (ARI). The study group had a median age of 21 months (IQR 7–60), with similar proportion of males and females (56.4 and 43.6% respectively) and 5.2% (CI 95 3.3–7.8%) prevalence of HMPV infection. The group with HMPV infection showed a greater frequency of viral coinfection (22.7% vs 14% P = 0.03) compared with ARI caused by other viruses. The rate of bacterial coinfection (P = 0.31), presence of comorbidities (p = 0.75), length of hospital stay (P = 0.42), need for mechanical ventilation (P = 0.75) and mortality (P = 0.22) were similar for HMPV and other viral infections. A moderate correlation was established between HMPV infection and rainfall peaks (Spearman’s Rho 0.44 p = 0.02).ConclusionsHuman metapneumovirus was the fifth most frequently isolated virus in children with ARI, had similar clinical behavior and severity to other viruses but a higher rate of viral coinfection. Its peaks seem to correlate to rainy seasons.

Detection of Respiratory Syncytial Virus and Human Metapneumovirus in Children with Respiratory Tract Infection by Use Real Time Polymerase Chain Reaction

Background: Respiratory tract illness is a major cause of morbidity and mortality among children, elderly and immunocompromised patients worldwide. Objective: To determine the infection rate of respiratory syncytial virus and human metapneumovirus among children with respiratory tract infection in Baghdad city. Patients and Methods: A cross sectional study was based on the processing of nasopharyngeal swabs from 150 children with acute respiratory tract infections, (81) males and (69)females; aged under five years old, who was admitted to Al-Imamin Al-Kadhimin Medical City and Pediatrics Protection Hospital in Baghdad during the period from December 2017 till April 2018. Nasopharyngeal swabs were collected from each participant and stored as frozen at -70 °C to use for RNA extraction and real time- polymerase chain reaction. Results: Out of all these samples, 54 samples were positive for respiratory syncytial virus (36%) and human metapneumovirus (1.33%). The infection rate of respiratory syncytial virus is more common in males (57.41%) than females and in children ≤ one year (37.04%) also high frequency were noticed among patients live in an urban area (72.22%) (50%) respectively and winter. According to different clinical feature, fever, cough, and wheezing were more common. Conclusion: The infection rate of respiratory syncytial virus was more than human metapneumovirus in children with respiratory tract infection using real time-PCR technique and the clinical manifestations were more common during respiratory syncytial virus and human metapneumovirus infection are cough, fever, wheezing.

Frequency and Molecular Typing of Human Metapneumovirus in Children with Acute Respiratory Tract Infection in Bojnurd, Northeastern Iran

Background: Acute respiratory infection plays a major role in hospitalization of children worldwide and viruses are one of the most important causative pathogens of acute respiratory tract infections (ARTIs). Human metapneumovirus (hMPV) is a respiratory pathogen responsible for ARTIs in infants and children around the world. The epidemiology of hMPV in the northeast of Iran is poorly described. This study aims to evaluate the prevalence and molecular types of hMPV in children under the age of 12 along with clinical relevance in northeast Iran. Methods: In this cross sectional study, from autumn 2015 to spring 2016 (nine months), 150 nasopharyngeal swabs were collected from children with ARTI and were evaluated for the presence of hMPV by reverse transcriptase-polymerase chain reaction (RT-PCR) technique; after that hMPV typing on positive samples was performed using PCR method. Results: Among the 150 patients that were included the study, 31 (20.6%) were positive for the hMPV genome. We also found that 96.8% (n = 30 cases) of positive cases belonged to genotype A; whereas no B genotype was detected. One of our hMPV isolates was non typable (3.2%). Conclusions: This study, for the first time, reports the existence of Human metapneumovirus virus in children with respiratory symptoms in northeastern Iran. We have also shown that the genotype A is the predominant circulating type among our patients.

Clinical characteristics and viral load of respiratory syncytial virus and human metapneumovirus in children hospitaled for acute lower respiratory tract infection.

Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) are two common viral pathogens in acute lower respiratory tract infections (ALRTI). However, the association of viral load with clinical characteristics is not well‐defined in ALRTI. To explore the correlation between viral load and clinical characteristics of RSV and HMPV in children hospitalized for ALRTI in Lanzhou, China. Three hundred and eighty‐seven children hospitalized for ALRTI were enrolled. Nasopharyngeal aspirates (NPAs) were sampled from each children. Real‐time PCR was used to screen RSV, HMPV, and twelve additional respiratory viruses. Bronchiolitis was the leading diagnoses both in RSV and HMPV positive patients. A significantly greater frequency of wheezing (52% vs. 33.52%, P = 0.000) was noted in RSV positive and negative patients. The RSV viral load was significant higher in children aged <1 year (P = 0.003), children without fever and wheezing (P = 0.015 and P = 0.000), days of illness <14 days (P = 0.002), children with bronchiolitis (P = 0.012) and children with RSV single infections (P = 0.000). No difference was found in the clinical features of HMPV positive and negative patients. The HMPV viral load had no correlation with any clinical characteristics. The incidences of severe disease were similar between single infection and coinfection for the two viruses (RSV, P = 0.221; HMPV, P = 0.764) and there has no statistical significance between severity and viral load (P = 0.166 and P = 0.721). Bronchiolitis is the most common disease caused by RSV and HMPV. High viral load or co‐infection may be associated with some symptoms but neither has a significant impact on disease severity for the two viruses. J. Med. Virol. 89:589–597, 2017 . © 2016 Wiley Periodicals, Inc.

Molecular epidemiology of human metapneumovirus in children with respiratory tract infection in Hangzhou

To understand the molecular epidemiologic features of human metapnenmovirus (hMPV) in children with respiratory tract infection in Hangzhou. 2 593 throat swabs were collected from patients with respiratory tract infections who visited the hospitals with sentinel surveillance programs from January 2011 to December 2013, including 1 676 outpatients and 917 inpatients. Total nucleic acid was extracted from the specimens and the fusion (F) protein gene of hMPV was amplified by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR), with positive samples picked to compare with the sequence of hMPV in GenBank, after the sequence of amplification products were determined. Other two types of common respiratory virus were tested using RT-PCR. The overall positive rate in this study was 6.51% (169/2 593), with 6.62% (111/1 676) in outpatients and 6.32% (58/917) in inpatients, but no statistically significant difference was found (χ(2) = 0.086, P = 0.769). The rates was 7.01% in males and 5.72% in females, with no statistically significant difference in different sex (χ(2) = 1.676, P = 0.195). The positive rate was 14.14% (28/198)in the 2-year-olds, 14.01% (22/158)in 3-year olds. The rate in 2-year olds was higher than in other groups, with statistically significant differences between the groups (χ(2) = 38.654, P = 0.000). Of the 169 positive cases, 153 (90.53%) in the younger than 5 years olds. The rates of infection with hMPV in winter and spring were statistically higher than in summer and autumn (χ(2) = 67.032, P = 0.000). The rate of co-infection was 19.52% (33/169). 88 amplified productions were selected for gene sequence analysis, and the F gene homology were 81.6%-100.0% with reference strains in GenBank. Data showed that all the 4 viral subtypes: A2 (52.27% , 46/88), B1 (37.51%, 33/88), B2 (9.09%, 8/88) and A1 (1.13%, 1/88) co-circulated during the study. However, different subtypes appeared predominant in different years:hMPV subtype B1 was in 2011 and 2012, subtype A2 in the end of 2012 and in 2013. Of the 88 specimens, gene sequences were determinate, with A genotype accounted for 67.56% (25/37), B genotype for 32.43% (12/37)in children younger than 1-year olds, and A genotype accounted for 43.13% (22/51), B genotype for 56.86% (29/51)in children above 1-year olds. Significant differences between the two groups (χ(2) = 5.143, P = 0.023) were noticed. It was confirmed that hMPV was one of the substantial pathogens causing the respiratory tract infections. Data from our study suggested that the peak time of hMPV infection predominated during winter and spring in Hangzhou. Both hMPV subtype B1 and subtype A2 were found popular in this study, with hMPV genotype A dominating in children younger than 1-year olds.

A Multicenter Outcomes Analysis of Children With Severe Viral Respiratory Infection Due to Human Metapneumovirus

To investigate the impact of human metapneumovirus on morbidity and mortality outcomes in children with severe viral respiratory infection. Retrospective cohort study. ICU, either PICU or cardiac ICU, at three urban academic tertiary care children's hospitals. All patients admitted to an ICU with laboratory-confirmed human metapneumovirus infection between January 2010 and June 2011. We captured demographic and clinical data and analyzed associated morbidity and mortality outcomes. There were 111 patients with laboratory-confirmed human metapneumovirus admitted to an ICU at one of the three participating institutions during the period of study. The median hospital length of stay was 7 days (interquartile range 4-18 days) and median ICU length of stay was 4 days (interquartile range 1-10 days). Ten patients (9%) did not survive to discharge. Predisposing factors associated with increased mortality included female gender (p = 0.002), presence of a chronic medical condition (p = 0.04), and hospital acquisition of human metapneumovirus infection (p = 0.006). Adjusting for female gender, chronic medical conditions, hospital acquisition of infection and severity of illness score, logistic regression analysis demonstrated that female gender, hospital acquisition of infection, and chronic medical conditions each independently increased the odds of mortality (odds ratios 14.8, 10.7, and 12.7, respectively). Analysis of our results suggests that there is substantial morbidity and mortality associated with severe viral respiratory infection due to human metapneumovirus in children. Female gender, hospital acquisition of human metapneumovirus infection, and presence of chronic medical conditions each independently increases mortality. The burden of illness from human metapneumovirus on the ICU in terms of resource utilization may be considerable.

Prevalence of human metapneumovirus in children with acute lower respiratory infection in Changsha, China.

Human metapneumovirus (hMPV) causes acute respiratory infections in children. The prevalence and clinical characteristics of hMPV were determined in nasopharyngeal aspirates of children in Changsha, China. Reverse transcription‐polymerase chain reaction (RT‐PCR) or PCR was employed to screen for both hMPV and other common respiratory viruses in 1,165 nasopharyngeal aspirate specimens collected from children with lower respiratory tract infections from September 2007 to August 2008. All PCR products were sequenced, and demographic and clinical data were collected from all patients. Seventy‐six of 1,165 (6.5%) specimens were positive for hMPV, of which 85.5% (65/76) occurred in the winter and spring seasons. The hMPV coinfection rate was 57.9% (44/76), and human bocavirus was the most common virus detected in conjunction with hMPV. Phylogenetic analysis revealed that 94.7% of the hMPV detected were of subgroup A2, 5.3% were subgroup B2, and none belonged to either the A1 or B1 subgroups. No significant differences were found in terms of the frequency of diagnosis and clinical signs between either the co‐ and mono‐infection groups, or between patients with and without underlying diseases. It was concluded that hMPV is an important viral pathogen in pediatric patients with lower respiratory tract infections in Changsha. Only hMPV genotypes A2 and B2 were co‐circulating in this locality; human bocavirus was the most common coinfecting virus, and coinfection did not affect disease severity. J. Med. Virol. 85:546–553, 2013. © 2013 Wiley Periodicals, Inc.

Rapid Detection of Human Metapneumovirus in Children with Acute Respiratory Tract Infection

Rapid Detection of Human Metapneumovirus in Children with Acute Respiratory Tract Infection

Prevalence and Characteristics of Human Metapneumovirus Infection Among Hospitalized Children at High Risk for Severe Lower Respiratory Tract Infection.

Human metapneumovirus (HMPV) is a significant cause of respiratory tract infections. Little is known about HMPV in children who are at high risk for lower respiratory tract infection (LRTI). To determine the prevalence of HMPV in high-risk children and to identify HMPV risk factors, children ≤24 months with prematurity, chronic lung disease, and/or congenital cardiac disease who were hospitalized with LRTI were prospectively enrolled. Nasopharyngeal aspirates were tested for HMPV, respiratory syncytial virus (RSV), influenza A and B, and parainfluenza types 1-3. Demographics, medical history, and outcomes for those with HMPV and RSV were compared. A multivariate analysis was performed to determine HMPV risk factors. Over 4 years, 1126 eligible children were enrolled. Pathogens were identified in 61% of subjects. HMPV was identified in 9.0%, second to RSV (45%). Coinfection with HMPV and RSV occurred in <1% of subjects. Subjects infected with HMPV were older (8.2 vs 4.0 months, P<.001), were born more prematurely (27 vs 33 weeks, P<.001), and more commonly had chronic lung disease (59.3% vs 21.8%, P<.001) compared with subjects infected with RSV. In a multivariate analysis that compared children infected with HMPV to all others, increasing age and household exposure to children ages 6-12 were associated with an increased risk, whereas birth at older gestational age and exposure to children age >12 were associated with a decreased risk. HMPV was detected in 9% of high-risk children who were hospitalized with lower respiratory tract disease, representing the second most common virus in this population. Compared with all other subjects (including RSV-infected), subjects infected with HMPV were older but were born more prematurely.

Molecular epideiological and clinical feature of human metapneumovirus in children with acute respiratory tract infection in Nanjing City

To investigate the molecular epideiological and clinical feature of human metapneumovirus in children with acute respiratory tract infection in Nanjing city, China. Nasopharyngeal aspirates and nasopharyngeal swab were taken from 642 outpatients or hospitalized pediatric patients with acute at the Children Hospital of Nanjing, Jiangsu Province, China, between August 2009 and July 2010. Respiratory speciments were tested for the M gene of hMPV by reverse-transcription polymerase chain reaction (RT-PCR). All RT-PCR positive products were sequenced and phlogenetic analysis was conducted. hMPV was detected in 35 (5.5%) of the 642 children. Phylogenetic analysis revealed that 51.4% of the hMPV were B1, 31.4% were A2b. The peak of the positive rate was in April. The majority of the hMPV-positive patients(71.4%) were 0-1 years old. Of the 35 hMPV-positive patients, 15 (42.8%) were co-infected with other respiratory viruses, and human rhinovirus (HRV) were the most common additional respiratory virus. The most common clinical diagnosis was pneumonia (48.6%). Human metapneumovirus is an important pathogen of acute respiratory tract infection in children in Nanjing city. The subtype B1 was the predominating lineage in 2009-2010 in Nanjing city. No significant differences were found for clinical characteristics between genotype A and genotype B human metapneumovirus infection in children in Nanjing.