Phylogenetic analysis and circulation pattern of human metapneumovirus strains in children with acute respiratory infection in Iran, 2014–2015

Aim: The aim of the present study was to investigate the prevalence and genetic variation of the human metapneumovirus (HMPV) G gene in children less than 8 years old with acute respiratory tract infections in Iran during 2014–2015. Materials & methods: To this end, 110 nasal swabs were tested for HMPV F gene. All positive samples were tested for the full length of HMPV G gene, then sequenced and analyzed for phylogenetic grouping. Results: Six (5.45%) out of 110 samples were positive for HMPV gene. Our HMPV sequences clustered into two main clusters: A2b (five isolates) and B1 (one isolate). The dN/dS ratio showed the presence of negative selective pressure. Conclusion: A2b was the predominant genotype during the study period in southwest of Iran.

A review on epidemiology and impact of human metapneumovirus infections in children using TIAB search strategy on PubMed and PubMed Central articles

Acute respiratory tract infections (ARTI) contribute to morbidity and mortality in children globally. Viruses including human metapneumovirus (hMPV) account for most ARTIs. The virus causes upper and lower respiratory tract infections mostly in young children and contributes to hospitalization of individuals with asthma,chronic obstructive pulmonary diseases and cancer. Moreover, hMPV pauses a considerable socio-economic impact creating a substantial disease burden wherever it has been studied, although hMPV testing is relatively new in many countries. We aimed to comprehensively analyze the epidemiological aspects including prevalence, disease burden and seasonality of hMPV infections in children in the world. We acquired published data extracted from PubMed and PubMed Central articles using the title and abstract (TIAB)search strategy for the major key words on hMPV infections from 9/54 African, 11/35 American, 20/50 Asian, 2/14 Australian/Oceanian and 20/51 European countries. According to the findings of this review, the prevalence of hMPV infection ranges from 1.1 to 86% in children of less than 5 years of age globally. Presence of many hMPV genotypes (A1, A2, B1, B2) and sub-genotypes (A2a, A2b, A2c, B2a, B2b) suggests a rapid evolution of the virus with limited influence by time and geography. hMPV infection mostly affects children between 2 to 5 years of age. The virus is active throughout the year in the tropics and epidemics occur during the winter and spring in temperate climates, contributing to a substantial disease burden globally.

Viral pathogens associated with acute respiratory illness in hospitalized adults and elderly from Zagreb, Croatia, 2016 to 2018

Aims

To investigate the viral etiology of acute respiratory infection (ARI) in hospitalized adults and elderly patients in Croatia, compare the prevalence of detected viruses, and to determine clinical characteristics and seasonal occurrence of investigated infections.

Methods

From January 2016 to June 2018, a total of 182 adult patients presented with symptoms of ARI and admitted to the hospital were tested for 15 respiratory viruses by multiplex reverse‐transcription polymerase chain reaction. Clinical data were collected by retrospective analysis of the patient's chart.

Results

A virus was identified in 106 (58.5%) of the patients. The most commonly detected virus was influenza virus (41.5%), followed by respiratory syncytial virus (13.8%), human metapneumovirus (13.0%), parainfluenza viruses (12.2%), rhinoviruses (11.4%), adenovirus and coronaviruses with equal frequencies (3.3%), and enterovirus (1.6%). The serum level of C‐reactive protein and white blood cell count were significantly lower in patients with respiratory viruses identified when compared with those in whom no virus was detected (P < 0.001 and P = 0.007, respectively). There were no differences in clinical symptoms according to the type of the detected virus, except for more frequent illness exposure recall for influenza infection ( P = 0.010). Influenza, parainfluenza, and pneumoviruses were detected mostly in winter months, while rhinoviruses in autumn and spring.

Conclusions

In addition to influenza, pneumoviruses, rhinoviruses, and parainfluenza viruses play an important role in etiology of ARIs in adults. Fast and accurate laboratory diagnosis for respiratory viruses in routine practice is needed for clinicians optimally manage patients with ARI and potentially avoid the unnecessary use of antimicrobial drugs.

Epidemiological and clinical features of human metapneumovirus in hospitalised paediatric patients with acute respiratory illness: a cross-sectional study in Southern China, from 2013 to 2016

OBJECTIVES

Human metapneumovirus (HMPV) is one of the most important respiratory viral pathogens affecting infants and children worldwide. Our study describes the epidemiological and clinical characteristics of HMPV present in patients hospitalised with acute respiratory illness (ARI) in Guangzhou, Southern China.

STUDY DESIGN

A cross-sectional study.

SETTING

Two tertiary hospitals in Guangzhou.

PARTICIPANTS AND METHODS

Throat swabs were collected over a 3-year period from 5133 paediatric patients (≤14 years) hospitalised with ARI. Patients who are HMPV positive with clinical presentations (101/103) were recorded for further analysis.

RESULTS

Of the 5133 patients included in the study, 103 (2.0%) were positive for HMPV. HMPV was more prevalent in children ≤5 years (2.2%, 98/4399) compared with older children (>5-14 years) (0.7%, 5/734) (P=0.004). Two seasonal HMPV peaks were observed each year and mainly occurred in spring and early summer. Overall, 18.4% (19/103) of patients who are HMPV positive were codetected with other pathogens, most frequently respiratory syncytial virus (36.8%, 7/19). Patients who are HMPV positive presented with a wide spectrum of clinical features, including cough (100.0%, 101/101), abnormal pulmonary breath sound (91.1%, 92/101), fever (88.1%, 89/101), expectoration (77.2%, 78/101), coryza (50.5%, 51/101) and wheezing (46.5%, 47/101). The main diagnosis of patients who are HMPV positive was bronchopneumonia (66.7%, 56/84). Fever (≥38˚C) (91.6%, 76/83) was detected more often in patients with only HMPV detected than in patients with HMPV plus other pathogen(s) detected (72.2%, 13/18) (P=0.037), whereas diarrhoea was more common in patients with HMPV plus other pathogen(s) detected (22.2%, 4/18), compared with patients with HMPV only (3.6%, 3/83) (P=0.018).

CONCLUSIONS

HMPV is an important respiratory pathogen in children with ARI in Guangzhou, particularly in children ≤5 years old. HMPV has a seasonal variation. Bronchopneumonia is a major diagnosis in patients who are HMPV positive.

Etiology and Clinical Characteristics of Single and Multiple Respiratory Virus Infections Diagnosed in Croatian Children in Two Respiratory Seasons

The aim of this study was to determine the causative agent of acute respiratory infection (ARI) in hospitalized children, as well as investigate the characteristics of ARIs with single and multiple virus detection in two respiratory seasons. In 2010 and 2015, nasopharyngeal and pharyngeal swabs from a total of 134 children, admitted to the hospital due to ARI, were tested using multiplex PCR. Viral etiology was established in 81.3% of the patients. Coinfection with two viruses was diagnosed in 27.6% of the patients, and concurrent detection of three or more viruses was diagnosed in 12.8% of the patients. The most commonly diagnosed virus in both seasons combined was respiratory syncytial virus (RSV) (28.6%), followed by parainfluenza viruses (PIVs) types 1–3 (18.4%), rhinovirus (HRV) (14.3%), human metapneumovirus (10.1%), adenovirus (AdV) (7.1%), influenza viruses types A and B (4.8%), and coronaviruses (4.2%). In 2015, additional pathogens were investigated with the following detection rate: enterovirus (13.2%), bocavirus (HBoV) (10.5%), PIV-4 (2.6%), and parechovirus (1.3%). There were no statistical differences between single and multiple virus infection regarding patients age, localization of infection, and severity of disease (P > 0.05). AdV, HRV, HBoV, and PIVs were significantly more often detected in multiple virus infections compared to the other respiratory viruses (P < 0.001).

Human metapneumovirus in patients hospitalized with acute respiratory infections: A meta-analysis

This meta-analysis aimed to estimate the prevalence of human metapneumovirus (hMPV) infections in patients hospitalized for acute respiratory infection (ARI) and to study factors associated with this prevalence. Medline and ScienceDirect databases were searched for prospective observational studies that screened hospitalized patients with ARI for hMPV by RT-PCR, with data available at December 27, 2014. The risk of bias was assessed regarding participation rate, definition of ARI, description of diagnostic technique, method of inclusion identical for all subjects, standardized and identical sampling method for all subjects, analysis performed according to the relevant subgroups, and presentation of data sources. Random-effect meta-analysis with arcsine transformation and meta-regressions was used. In the 75 articles included, the prevalence of hMPV among hospitalized ARI was 6.24% (95% CI 5.25-7.30). An effect of the duration of the inclusion period was observed (p=0.0114), with a higher prevalence of hMPV in studies conducted during periods of 7-11 months (10.56%, 95% CI 5.97-16.27) or complete years (7.55%, 95% CI 5.90-9.38) than in periods of 6 months or less (5.36%, 95% CI 4.29-6.54). A significant increase in the incidence with increasing distance from the equator was observed (p=0.0384). hMPV should be taken into account as a possible etiology in hospitalized ARI.

Prevalence and molecular characterization of human metapneumovirus in influenza a negative sample in Thailand

Background

Human metapneumovirus (hMPV) causes respiratory tract infection in influenza‐like illness. The role of hMPV infections in all age groups in Thailand has not yet been investigated. Thus, the objective of this study was to determine prevalence of hMPV infection in all age groups in Thailand during 2011.

Methods

A total of 1,184 nasopharyngeal washes were collected from hospitalized patients and sent to the Department of Microbiology, Siriraj Hospital, for influenza A virus detection. Real‐time polymerase chain reaction (PCR) was used to detect hMPV infection. Partially, F gene from hMPV positive samples were sequenced and used for genotyping by phylogenetic tree analysis.

Results

The prevalence of hMPV for all age groups was 6.3%. The highest prevalence of hMPV infection was in children aged <2 years. Of 71 hMPV‐positive patients, three (4.2%) were coinfected with respiratory syncytial virus (RSV), two with rhinovirus (2.8%), one with coronavirus (1.4%), and one with RSV and adenovirus (1.4%). Phylogenetic analysis of F gene revealed that 96.8% of hMPV detected was subgenotype B1, 1.6% was sublineage A2a, and 1.6% was A2b. Genetic variation of F gene was much conserved.

Conclusion

We demonstrated the prevalence of hMPV subgenotype B1 circulating in Thailand during 2011.

Human metapneumovirus: insights from a ten-year molecular and epidemiological analysis in Germany

Human metapneumovirus (HMPV) is a cause of respiratory tract illness at all ages. In this study the epidemiological and molecular diversity among patients of different ages was investigated. Between 2000-2001 and 2009-2010, HMPV was detected in 3% (138/4,549) of samples from outpatients with influenza-like illness with a new, sensitive real-time RT-PCR assay. Several hundred (797) clinical specimens from hospitalized children below the age of 4 years with acute respiratory illness were investigated and HMPV was detected in 11.9% of them. Investigation of outpatients revealed that HMPV infections occurred in individuals of all ages but were most prevalent in children (0-4 years) and the elderly (>60 years). The most present clinical features of HMPV infections were cough, bronchitis, fever/shivers and pneumonia. About two thirds of HMPV-positive samples were detected in February and March throughout the study period. Molecular characterization of HMPV revealed a complex cyclic pattern of group dominance where HMPV subgroup A and B viruses predominated in general for three consecutive seasons. German HMPV represented all genetic lineages including A1, A2, B1, B2, sub-clusters A2a and A2b. For Germany, not only time-dependent circulation of lineages and sub-clusters was observed but also co-circulation of two or three predominant lineages. Two newly emerging amino acid substitutions (positions 223 and 280) of lineage B2 were detected in seven German HMPV sequences. Our study gives new insights into the molecular epidemiology of HMPV in in- and outpatients over a time period of 10 years for the first time. It is one of only few long-term surveillance studies in Europe, and allows comparative molecular analyses of HMPV circulating worldwide.

Seasonal occurrence of human metapneumovirus infections in Croatia

BACKGROUND

Human metapneumovirus (HMPV) is 1 of the commonest causes of viral ARI especially among pediatric patients. Its incidence varies from year to year in countries belonging to moderate climate zone. The aim of this study was to investigate epidemiologic characteristics of HMPV infections in Croatia.

METHODS

During a 4-year period (January 1, 2009, through December 31, 2012), nasopharyngeal aspirates were collected from 2610 children <10 years who were admitted to hospitals with acute respiratory infections. Direct immunofluorescence assay was used to detect the virus from clinical samples. Demographics and clinical data were also analyzed.

RESULTS

HMPV was detected in 8.4% of patients. While many of HMPV-infected children were 13-24 months of age (30.9% of all proven HMPV infections), the highest incidence of HMPV infection was recorded in 2- to 5-year-old children (11.4% of all children in this age group). HMPV caused 7.1% of upper respiratory tract infections and 11.7% of lower respiratory tract infections. Annual prevalence rates of HMPV infection varied significantly from year to year (P < 0.001). Peak incidence was detected in spring or winter months, depending on the year.

CONCLUSIONS

This study indicates that HMPV infections in Croatia show a biennial outbreak pattern characterized by alternation of winter and spring activity. HMPV outbreaks alternate with respiratory syncytial virus outbreaks.

Genetic variability of human metapneumo- and bocaviruses in children with respiratory tract infections

OBJECTIVES

The genotypic analysis of human metapneumo-(HMPV) and boca-(HBoV) viruses circulating in Greece and their comparison to reference and other clinical strains.

DESIGN

Genetic analysis of representative strains over three consecutive winter seasons of the years 2005-2008.

SETTING

Representative positive specimens for HMPV and HBoV from paediatric patients of healthcare units and hospitals in Southern Greece with influenza-like illness or other respiratory tract infections.

SAMPLE

Seven to ten positive specimens for either HMPV or HBoV from each winter period. In total, 24 specimens positive for HMPV and 26 for HBoV, respectively.

MAIN OUTCOME MEASURES

Sequence diversity of HMPV and HBoV strains by sequencing the complete G and VP1/VP2 genes, respectively.

RESULTS

In total, 24 HMPV strains were found to have a 92-100% nucleotide and a 85.9-100% amino acid identity. Phylogenetic analysis based on the number of amino acid differences, revealed circulation of 4 different subclusters belonging to genetic lineage B2. Similarly, analysis of 26 HBoV strains indicated that 22 clustered within genotype St2, 2 into genotype St1 and the remaining 2 formed a third cluster derived from potential recombination between different St1 genotype strains. St2 HBoV genotype was observed throughout the whole observation period whereas St1 only during the second and the third winter period. Higher levels of heterogeneity were observed between HMPV compared to HBoV strains.

CONCLUSIONS

Phylogenetic analysis revealed circulation of one single lineage (B2) for HMPV viruses and predominance of St2 genotype for HBoV viruses. A possible recombination between St1 genotype strains of HBoV was observed.

Human metapneumovirus-associated hospital admissions over five consecutive epidemic seasons: evidence for alternating circulation of different genotypes

Human metapneumovirus (hMPV) is a pathogen of the respiratory tract with a worldwide distribution. The purpose of this study was to identify hMPV as the cause of acute respiratory diseases in children admitted at Spedali Civili, a public hospital in Brescia, Italy. Eight hundred forty‐six nasopharyngeal aspirate samples negative for the presence of other common respiratory viruses were tested for the presence of hMPV RNA by reverse transcription‐polymerase chain reaction. Of the 846 samples, 79 (9.3%) were positive for hMPV. Polymerase chain reaction products, obtained by amplification of the partial nucleotide sequence of gene F, were sequenced and compared with sequences deposited in GenBank. All four hMPV subtypes were identified, including the proposed subtype A2 sublineages “A” and “B”. In successive epidemic seasons, large outbreaks of hMPV alternated with small outbreaks in a biannual pattern. This local study provides further evidence that hMPV infection should be considered as a reason for hospital admission for acute respiratory disease in children. J. Med. Virol. 84:511–516, 2012. © 2011 Wiley Periodicals, Inc.

Human Metapneumovirus: lessons learned over the first decade

It has been 10 years since human metapneumovirus (HMPV) was identified as a causative agent of respiratory illness in humans. Since then, numerous studies have contributed to a substantial body of knowledge on many aspects of HMPV. This review summarizes our current knowledge on HMPV, HMPV disease pathogenesis, and disease intervention strategies and identifies a number of areas with key questions to be addressed in the future.

Prevalence of human metapneumovirus in hospitalized children with respiratory tract infections in Tianjin, China

Human metapneumovirus (hMPV) has recently been recognized as an important respiratory pathogen, especially in children. At present, our understanding of the characteristics of hMPV from China is very limited. Nasopharyngeal aspirates were taken from 310 hospitalized pediatric patients. Twenty (6.5%) of them were infected with hMPV, and they all developed pneumonia. Sixty five percent (13/20) of the cases were under 12 months. Phylogenetic analysis of F gene fragments indicated that three sub-genotypes of hMPV(A2a/A2b, B1,B2) circulated in Tianjin and A2b was the predominant subtype. The Vero-E6 cell line was better than LLC-MK2 for hMPV isolation. Three hMPV strains were successfully isolated using the Vero-E6 cell line.

Reliability of real-time reverse-transcription PCR in clinical diagnostics: gold standard or substandard?

Molecular diagnostics is one of the major growth areas of modern medicine, with real-time PCR established as a qualitative and quantitative technology that is rapid, accurate and sensitive. The sequencing of the human genome, comprehensive genomic, mRNA and miRNA expression profiling of numerous cancer types, the ongoing identification of disease-associated polymorphisms and the expanding availability of genomic sequence information for human pathogens has opened the door to a wide range of translational applications for this technology. Consequently, novel real-time PCR assays have been developed for diagnosis and prognosis, treatment monitoring, transplant biology and pathogen detection, as well as more controversial uses such as lifestyle genotyping. However, this technology is still troubled by significant technical deficiencies. Hence its often-improper use as a clinical tool has important public health implications, most recently demonstrated through its association with the measles, mumps and rubella vaccine/autism controversy. This serves as a timely reminder of the indispensable requirement for careful experimental design, validation and analysis.