High prevalence of human metapneumovirus subtype B in cases presenting as severe acute respiratory illness: an experience at tertiary care hospital

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

BACKGROUND

Acute 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.

METHODS

Children 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.

RESULTS

RSV 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.

CONCLUSION

RSV 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 61.5 months (5.1 years) and 83 months (6.9 years), 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.

An Amplicon-Based Approach for the Whole-Genome Sequencing of Human Metapneumovirus

Human metapneumovirus (HMPV) is an important cause of upper and lower respiratory tract disease in individuals of all ages. It is estimated that most individuals will be infected by HMPV by the age of five years old. Despite this burden of disease, there remain caveats in our knowledge of global genetic diversity due to a lack of HMPV sequencing, particularly at the whole-genome scale. The purpose of this study was to create a simple and robust approach for HMPV whole-genome sequencing to be used for genomic epidemiological studies. To design our assay, all available HMPV full-length genome sequences were downloaded from the National Center for Biotechnology Information (NCBI) GenBank database and used to design four primer sets to amplify long, overlapping amplicons spanning the viral genome and, importantly, specific to all known HMPV subtypes. These amplicons were then pooled and sequenced on an Illumina iSeq 100 (Illumina, San Diego, CA, USA); however, the approach is suitable to other common sequencing platforms. We demonstrate the utility of this method using a representative subset of clinical samples and examine these sequences using a phylogenetic approach. Here we present an amplicon-based method for the whole-genome sequencing of HMPV from clinical extracts that can be used to better inform genomic studies of HMPV epidemiology and evolution.

Human Metapneumovirus Induces Mucin 19 Which Contributes to Viral Pathogenesis

Human Metapneumovirus (HMPV) remains one of the most common viral infections causing acute respiratory tract infections, especially in young children, elderly, and immunocompromised populations. Clinical symptoms can range from mild respiratory symptoms to severe bronchiolitis and pneumonia. The production of mucus is a common feature during HMPV infection, but its contribution to HMPV-induced pathogenesis and immune response is largely unknown. Mucins are a major component of mucus and they could have an impact on how the host responds to infections. Using an in vitro system and a mouse model of infection, we identified that Mucin 19 is predominantly expressed in the respiratory tract upon HMPV infection. Moreover, the lack of Muc19 led to an improved disease, lower lung viral titers and a decrease in the number of CD4+ T cells. These data indicate that mucin 19 contributes to the activation of the immune response to HMPV and to HMPV-induced pathogenesis.

The burden of respiratory syncytial virus in adults: a systematic review and meta-analysis

Respiratory syncytial virus (RSV) is the most common pathogen associated with acute lower respiratory tract infections in young children. RSV is also a major viral pathogen causing severe lung disease in the adult population, particularly among the elderly. We conducted a review of adult RSV studies published from January 1970 to February 2017 to determine the burden of disease among adults worldwide. There were no restrictions on health care setting or definition of RSV infection. A total of 1530 published studies were identified, 95 of which were included in this review. The incidence rates of hospitalised RSV acute respiratory tract infection (ARI) in adults >65 years old ranged from 7.3 to 13.0/10⁵ population in Africa and Asia and from 190 to 254/10⁵ population in the USA. Higher incidence rates (195–1790/10⁵ population) were observed in adults ≥50 years old for outpatient or emergency visits in the USA. Of all ARI patients, RSV accounted for 1–10% in adults and 2–14% in patients with chronic diseases or transplantation. Given the limitations in the existing data, significant efforts should be made to generate evidence on the burden of RSV infections in adults and to estimate the potential impact of future preventive interventions.

Epidemiology of RSV and hMPV in Belgium: a 10-year follow-up

Objectives: Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) are important respiratory pathogens. Both viral pathogens have similar clinical manifestations. The epidemiology of RSV is well known, that of hMPV is less clear. We reviewed the results of 10 consecutive years of molecular testing for RSV and hMPV in respiratory samples of Flemish patients. Methods: In the laboratory of the OLV hospital Aalst, Belgium, multiplex RT-PCR assays are used for the detection of RSV and hMPV. The lab receives invasive and noninvasive respiratory samples of patients from all over Flanders. Results: Between September 2006 and August 2016, 16,826 respiratory samples were analyzed for RSV and hMPV. Of these samples, 18% tested positive for RSV and 7.3% for hMPV. RSV consistently peaked in November/December each year within a very narrow time frame. The occurrence of hMPV was less predictable and spreaded more widely throughout the winter and spring. Both viruses were mainly found in samples from young children. RSV was most frequently detected in samples from infants <3 months, while hMPV peaked between 6 and 9 months. After the age of 1 year, RSV rapidly dropped. hMPV dropped a little later and slower. Both viruses slightly increased again at older age (>50 years). Conclusions: Despite their similarities, some of the epidemiologic characteristics of hMPV and RSV differ. The most striking difference is the annual distribution of RSV and hMPV infections.

Epidemiological, clinical and genotypic features of human Metapneumovirus in patients with influenza-like illness in Senegal, 2012 to 2016

BACKGROUND

Human metapneumovirus (HMPV) is a causal agent of acute respiratory infection, especially in primarily children. At the clinical level, HMPV is associated to several diseases including bronchitis, croup, pneumonia, bronchiolitis, reactive airway disease, chronic obstructive pulmonary disease and asthma exacerbations, specifically in children less than 5 years. Here, we carried out a retrospective pilot study, based on the processing of nasopharyngeal swabs, with a focus on the epidemiology and molecular characteristics of HMPV in Senegal.

METHODS

This retrospective study was conducted from January 2012 to December 2016. Briefly, all outpatients presenting to healthcare sentinel sites were screened for surveillance enrollment and included if they met criteria for ILI. Naso-oropharyngeal swabs were collected from eligible participants. For viral respiratory pathogens detection, including HMPV, the Anyplex™ II RV16 Detection kit was used. A fragment of the hMPV F gene was targeted for sequencing.

RESULTS

In total, 8209 patients with ILI were enrolled. Half of them (49.7%) were children under 5 years. Fever was the most common symptom followed by cough, and rhinitis. Three hundred eight patients were positive for HMPV (3.75%). 89 (28.9%) were detected as single infection. In co-infection cases, the most common co-infecting viruses were influenza, adenovirus and rhinovirus. HMPV detection rates in the different age groups varied significantly with the children under 5 years group accounting for 71.7% of positive patients. The temporal distribution pattern for HMPV infection showed a clear seasonal pattern with a higher activity during the rainy period (July-September). Phylogenetic analyses revealed that HMPV specimens circulating in Senegal were distributed into the two main genetic lineages, A and B. We also noted a co-circulation of both genetic lineages during the whole study period except in 2014.

CONCLUSION

In summary, the present study characterized the recent prevalence, seasonality and genetic diversity of HMPV in a large outpatient population presented with ILI in Senegal between 2012 and 2016. Globally our results show a clear seasonal circulation pattern of HMPV in Senegal. Our findings identified children less than 5 years as more susceptible group to HMPV infection. Molecular studies identified A2, B1 and B2 as the major genotypes circulating.

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.

Treatment For The Large Aggressive Benign Lesions Of The Jaws

Objectives

Our aim was to evaluate the clinical outcome of the conservative management of the significantly large benign aggressive lesions of the jaws.

Subjects and Methods

Twenty-two patients were reviewed regarding the demographic, radiographic, and operative findings. Patients were treated by decompression followed by curettage or only with curettage.

Results

No bone grafts were used. Mean follow-up time was 56.2 months. The mandible was more affected than the maxilla. Two of the ameloblastoma, two of the keratocystic odontogenic tumours, and one odontogenic myxoma were recurred.

Conclusions

Despite the low number of the patients, it is concluded that the conservative management is predictable for the management of the benign aggressive lesions in order to reduce morbidity instead of directly performing radical surgery. The life during follow-up is mandatory in the situation of performing conservative surgery for the management of large aggressive lesions with high recurrence rate.

Legionnaire's Disease and its Mimics: A Clinical Perspective

Whenever the cardinal manifestations of a disorder occur in similar disorders, there is potential for a disease mimic. Legionnaire's disease has protean manifestations and has the potential to mimic or be mimicked by other community acquired pneumonias (CAPs). In CAPs caused by other than Legionella species, the more characteristic features in common with legionnaire's disease the more difficult the diagnostic conundrum. In hospitalized adults with CAP, legionnaire's disease may mimic influenza or other viral pneumonias. Of the bacterial causes of CAP, psittacosis and Q fever, but not tularemia, are frequent mimics of legionnaire's disease.

Prevalence of Human metapneumovirus infection among patients with influenza-like illness: Report from a Tertiary Care Centre, Southern India

BACKGROUND

Human metapneumovirus (HMPV), discovered in the 21st century, has emerged as an important cause of influenza-like illness in children and adults causing mild upper respiratory tract infection to severe bronchiolitis and community-associated pneumonia. The aim of this study was to determine the prevalence of HMPV in the Union Territory of Puducherry, India, as part of National Influenza Surveillance Programme.

MATERIALS AND METHODS

From November 2011 to December 2013, a total of 447 nasopharyngeal samples were collected from patients with acute respiratory infections and tested for HMPV RNA by real-time polymerase chain reaction.

RESULTS

HMPV was identified in 23/447 (5%) samples with 11/23 in the age group of 14-30 years. Most of the HMPV infections were mild with no fatalities. Two patients were co-infected with the respiratory syncytial virus and one with influenza B virus. The seasonal distribution showed increasing HMPV infection cases in rainy months except for a peak in summer of 2012. Phylogenetic analysis based on the sequences of the nucleoprotein gene of one HMPV strain showed a high degree of sequence identity with Indian strains obtained during 2006 and 2011.

CONCLUSION

This study shows that HMPV infection is more common in adults than in children. Sequence homology suggests the circulation of closely related HMPV strains within the country.

Development of a multiplex RT-PCR for simultaneous diagnosis of human metapneumovirus (HMPV) and human respiratory syncytial virus (HRSV) from clinical specimens

Human metapneumovirus (HMPV) and human respiratory syncytial virus (HRSV) are ubiquitous respiratory viral pathogens. They belong to the family Paramyxoviridae (subfamily Pneumovirinae) and is responsible for acute respiratory tract infections in children, elderly and immunocompromised patients. We designed and tested a multiplex reverse transcriptase polymerase chain reaction (mRT-PCR) as a cost-effective alternative to real-time PCR and cell culture based detection for HMPV and HRSV. The newly developed PCR was used to screen nasal/throat swab samples from 356 patients with suspected acute respiratory infection attending the Government Medical College, Thiruvananthapuram, Kerala, India. The method was compared with a commercially available kit employing real time PCR, for its sensitivity and specificity. 53 (14.9 %) samples were positive for at least one tested pathogen by mRT-PCR. All except one among the positive samples showed similar pathogen profile when tested using real time PCR. 8 (15.1 %) among these 53 were positive for HRSVA, 33 (62.3 %) positive for HRSVB and 12 (22.6 %) were positive for HMPV. 17 (32.7 %) samples showed co-infections in them. Sensitivity and specificity of the mRT-PCR was comparable to that of the commercial kit. Our findings indicate that this newly developed mRT-PCR can be used as a cost-effective alternative for laboratory diagnosis of HMPV/HRSV infection and will significantly reduce diagnostic costs for these viruses in clinical settings.

Etiology, seasonality, and clinical characteristics of respiratory viruses in children with respiratory tract infections in Eastern India (Bhubaneswar, Odisha)

Acute respiratory tract infections (ARTIs) are a leading cause of morbidity and mortality in young children in low and middle income countries. To analyse the overall burden of respiratory viruses responsible for ARTIs in paediatrics population in eastern India, this study was performed. Clinical information, demographic information and nasal/oral swabs were collected from 332 paediatric patients (aged from 1 month to 12 years old) with the symptoms of ARTI, enrolled from the outpatient department from Nov 2012 to Oct 2014. Multiplex PCR was performed to detect eight respiratory viral pathogens. Seasonal, as well as age-wise prevalence of respiratory viruses was analysed. Of these 332 cases, 32.53% (108/332) were positive for at least one pathogen. Human rhinovirus (HRV) was the most frequently detected pathogen (24.7%, 82/332) followed by respiratory syncytial virus (RSV) (4.22%, 14/332), PIV (2.11%, 7/332), and hMPV (2.11%, 7/332). Single infection was detected in 92.6% (100/108) of positive cases. Respiratory virus infections showed seasonal variation, with peaks during the rainy season followed by winter season, and were most common in patients under 1 year of age. Phylogenetic analysis of HMPV positive samples confirmed the circulation of A2 subgroup in the study area. The present study is first of its kind and adds to our knowledge of the epidemiological characteristics of these common respiratory viruses among patients with ARTIs in the study area. J. Med. Virol. 89:553-558, 2017. © 2016 Wiley Periodicals, Inc.

Clinical characterization of influenza A and human respiratory syncytial virus among patients with influenza like illness

Influenza A and Respiratory Syncytial Virus (RSV) has been recognized as a major cause of acute respiratory tract infection. H1N1 is one of the subtypes of influenza A, pandemic worldwide in July 2009, causing 18,449 deaths globally. To investigate the prevalence and clinical manifestation of the influenza A, H1N1pdm09, and RSV. Throat/nasal swab collected from the patients of all age group either outpatients/inpatients having respiratory illness from 2 to 5 days. The clinical data were recorded in a predesigned questionnaire. RNA was extracted and analyzed by real time PCR at a tertiary care center, 2009-2014. Total 4,352 samples tested for influenza A and H1N1. Out of 4,352, 32.2% (median positivity 21%; range 16-41% during 6 years) were positive for influenza A and 19% were H1N1 (median positivity 16.7%; range 8.7-23% during 6 years). Total 1653 samples were analyzed for RSV from 2011 to 2014, 12% were RSV positive (median positivity 11.35%; range 10-16.3% during 4 years). Pharyngitis, dyspnea were frequent symptoms in influenza A and H1N1 (P < 0.005) whereas bronchiolitis and pneumonia were commonly present in RSV (P < 0.005). The positivity of influenza A and H1N1 was higher in age-group 21-30, whereas RSV in infant and children. H1N1 and RSV were co-circulated and have common clinical symptoms particularly in lower age group. Therefore, laboratory confirmation is necessary for further disease prognosis. Age was an important risk factor that affects the positivity of influenza A, H1N1, and RSV. Different clinical manifestation of H1N1 and RSV will be helpful for early and accurate diagnosis. J. Med. Virol. 89:49-54, 2017. © 2016 Wiley Periodicals, Inc.

BCSH/BSBMT/UK clinical virology network guideline: diagnosis and management of common respiratory viral infections in patients undergoing treatment for haematological malignancies or stem cell transplantation

A joint working group established by the Haemato-oncology subgroup of the British Committee for Standards in Haematology, the British Society for Bone Marrow Transplantation and the UK Clinical Virology Network has reviewed the available literature and made recommendations for the diagnosis and management of respiratory viral infections in patients with haematological malignancies or those undergoing haematopoietic stem cell transplantation. This guideline includes recommendations for the diagnosis, prevention and treatment of respiratory viral infections in adults and children. The suggestions and recommendations are primarily intended for physicians practising in the United Kingdom.

Adult human metapneumonovirus (hMPV) pneumonia mimicking Legionnaire's disease

In adults hospitalized with viral pneumonias the main differential diagnostic consideration is influenza pneumonia. The respiratory viruses causing viral influenza like illnesses (ILIs), e.g., RSV may closely resemble influenza. Rarely, extrapulmonary findings of some ILIs may resemble Legionnaire's disease (LD), e.g., adenovirus, human parainfluenza virus (HPIV-3). We present a most unusual case of human metapneumonovirus pneumonia (hMPV) with some characteristic extrapulmonary findings characteristic of LD, e.g., relative bradycardia, as well as mildly elevated serum transaminases and hyphosphatemia. We believe this is the first reported case of hMPV pneumonia in a hospitalized adult that had some features of LD.

Human metapneumovirus: review of an important respiratory pathogen

Human metapneumovirus (hMPV), discovered in 2001, most commonly causes upper and lower respiratory tract infections in young children, but is also a concern for elderly subjects and immune-compromised patients. hMPV is the major etiological agent responsible for about 5% to 10% of hospitalizations of children suffering from acute respiratory tract infections. hMPV infection can cause severe bronchiolitis and pneumonia in children, and its symptoms are indistinguishable from those caused by human respiratory syncytial virus. Initial infection with hMPV usually occurs during early childhood, but re-infections are common throughout life. Due to the slow growth of the virus in cell culture, molecular methods (such as reverse transcriptase PCR (RT-PCR)) are the preferred diagnostic modality for detecting hMPV. A few vaccine candidates have been shown to be effective in preventing clinical disease, but none are yet commercially available. Our understanding of hMPV has undergone major changes in recent years and in this article we will review the currently available information on the molecular biology and epidemiology of hMPV. We will also review the current therapeutic interventions and strategies being used to control hMPV infection, with an emphasis on possible approaches that could be used to develop an effective vaccine against hMPV.