Seasonal occurrence of human metapneumovirus infections in Croatia

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.

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.

Molecular epidemiology of human respiratory syncytial virus and human metapneumovirus in hospitalized children with acute respiratory infections in Croatia, 2014-2017

Acute respiratory infection (ARI) is the most common infection in children under 5 years of age and it is frequently caused by two pneumoviruses, human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV). Epidemic seasons of these viruses overlap and disease manifestations are highly similar, including severe lower ARI such as bronchiolitis or pneumonia. Reinfections with pneumoviruses are frequent and limited prevention treatment is available. Genetic diversity of HRSV and HMPV strains circulating in Croatia was monitored during four consecutive years (2014-2017). Co-circulation of multiple lineages was observed for both viruses. Within HRSV group A, ON1 strains gained strong predominance during the 4-year period, while previously dominant genotype NA1 was detected only sporadically. Similarly, newly occurring HMPV genotype A2c gained predominance over genotype A2b during this period, resulting in all infection in 2017 being caused by A2c. Along with phylogenetic analysis based on the commonly used fragments for detection and genotyping of these viruses, full length G and SH genes were also analysed. Evolutionary dynamics showed that inferred substitution rates of HRSV and HMPV are between 2.51 × 10^-3 and 3.61 × 10^-3 substitutions/site/year. This study established presence of recently described HMPV strains containing large duplications in the G gene in Croatia. Viruses with either of the two duplications belong to a subcluster A2c, which has completely replaced all other group A subclusters in 2017.

Human metapneumovirus in Pediatric Patients with Acute Respiratory Tract Infections in the Aseer Region of Saudi Arabia

Background:

Human metapneumovirus (hMPV) is a Paramyxovirus known to cause acute respiratory tract infections in children and young adults. To date, there is no study from the Aseer region of Saudi Arabia determining the proportion and severity of hMPV infection among pediatric hospitalized patients with respiratory infections.

Objectives:

The objective of this study is to determine the presence of hMPV antigens in the nasopharyngeal secretions of pediatric patients hospitalized with respiratory tract infections in the Aseer region of Saudi Arabia.

Materials and Methods:

This prospective, serological hospital-based study included all pediatric patients who were admitted to Aseer Central Hospital, Abha, Saudi Arabia, from July 2016 to November 2017 with upper and/or lower respiratory tract infections. Basic demographics of patients and their clinical data on and after admission were recorded. Direct fluorescent antibody assay was used to detect the presence of hMPV antigens in the obtained nasopharyngeal secretion specimens.

Results:

During the study, 91 pediatric patients were hospitalized due to upper and/or lower respiratory tract infections, of which 9.9% were positive for hMPV. These patients were aged 9 months to 16 years, were from Abha city or its surrounding localities and were mostly (77.8%) hospitalized during autumn or winter. The most common diagnosis on admission was bronchopneumonia (55.5%) and aspiration pneumonia (22.2%), and some patients also had underlying chronic conditions such as chronic heart disease (22.2%) and bronchial asthma (11.1%).

Conclusions:

The results obtained indicated that hMPV is a potential etiologic factor for the commonly occurring acute respiratory infections in hospitalized children from the Aseer region of Saudi Arabia. hMPV infection was also found to be associated with complicated respiratory conditions such as bronchopneumonia, chronic heart disease and bronchial asthma.

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.

Genetic characterization of human metapneumovirus identified through community and facility-based surveillance of infants in Dhaka, Bangladesh

BACKGROUND

Acute respiratory infection (ARI) is a leading cause of morbidity and mortality in children in low and middle-income countries. Human metapneumovirus (hMPV) is one of the most common viral etiological agents for ARIs in children.

OBJECTIVES

In this study, we explored the genotypic diversity and the epidemiology of hMPV among infants in Dhaka, Bangladesh.

STUDY DESIGN

Between December 2014 and August 2016, a total of 3810 mid-turbinate nasal swab samples were collected from infants (0 to 6 months of age) who met clinical ARI criteria, as a part of a prospective ARI cohort study. hMPV was detected using polymerase chain reaction, and genotyped by sequencing and phylogenetic analysis.

RESULTS

hMPV was identified in 206 (5.4%) nasal swab specimens. One-tenth of the hMPV-positive swabs (n = 19) were also positive for other respiratory viruses. hMPV activity peaked in January and September in 2015; however, no seasonal pattern of hMPV infection was detected. Phylogenetic analyses of the N and F gene-fragments revealed that the hMPV strains circulating in Dhaka, Bangladesh, belonged to three genotypes: A2b, A2c, and B1. Genotype A (57%) was the predominant hMPV genotype circulating in Bangladesh during the study period.

CONCLUSION

This study describes both the epidemiology of hMPV infection and its genotypic strain diversity in Dhaka, Bangladesh.

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).

A study of genetic variability of human parainfluenza virus type 1 in Croatia, 2011-2014

Molecular epidemiology of human parainfluenza viruses type 1 (HPIV1) was investigated. Samples were collected from patients hospitalized in Croatia during the three consecutive epidemic seasons (2011-2014). Results indicated co-circulation of two major genetic clusters of HPIV1. Samples from the current study refer to clades II and III in a phylogenetic tree of haemagglutinin-neuraminidase (HN) gene. Additional phylogenetic trees of fusion (F) and phosphoprotein (P) genes confirmed the topology. Analysis of nucleotide diversity of entire P, F and HN genes demonstrated similar values: 0.0255, 0.0236 and 0.0237, respectively. However, amino acid diversity showed F protein to be the most conserved, while P protein was the most tolerant to mutations. Potential N- and O-glycosylation sites suggested that HPIV1 HN protein is abundantly glycosylated, and a specific N-glycosylation pattern could distinguish between clades II and III. Analysis of potential O-glycosylation sites in F protein indicated that samples from this study have two potential O-glycosylation sites, while publicly available sequences have five potential sites. This study provides data on the molecular characterization and epidemic pattern of HPIV1 in Croatia.

Evaluation of epidemiological and clinical features of influenza and other respiratory viruses

AIM

In our study, we aimed to clinically and epidemiologically evaluate respiratory tract infections the viral agents of which were detected by molecular methods and to compare influenza and other respiratory tract viruses in this context.

MATERIAL AND METHODS

The records of 178 patients aged above 2 years who presented to pediatric emergency outpatient clinic with fever and respiratory tract infection findings between December 2013 and April 2014 were examined retrospectively.

RESULTS

At least one respiratory tract pathogen was detected by polymerase chain reaction in 78.6% (n=140) of the patients: influenza A 33.5%, influenza B 16.4%, respiratory syncytial virus 9.2%, adenovirus 7.8%, rhinovirus 7.1%, coronavirus 7.1%, human metapneumovirus 5.7%, human bocavirus 5.7%, parainfluenza virus 3.5%, coinfection 2.8%. The mean age of the patients was 6.3±3.6 years. Sixty-nine patients (49.2%) were aged between 2 and 5 years. Seventy-one patients (50.7%) were aged 5 years and above. Upper respiratory tract infection was found with a rate of 65.7% and lower respiratory tract infection was found with a rate of 34.2%. It was observed that the distribution of respiratory tract viruses showed variance by age groups. Influenza A infection was observed with the highest rate in both age groups. Influenza B was the second leading agent (p=0.008) above the age of 5 years and respiratory syncytial virus was the second leading agent in the 2-5 year age group (p=0.003). Influenza viruses were detected in 55.9% of 118 patients who were found to be compatible with the definition of "influenza-like illness" specified in the Center for Disease Control and Prevention guidelines and other viral agenst were detected in 44%. No difference could be found between the clinical pictures and radiological findings caused by influenza and other respiratory tract viruses.

CONCLUSIONS

In this study, it was concluded that influenza and other respiratory viruses can not be differentiated definitely by clinical and radiological findings, though there are some differences.

Environmental viral contamination in a pediatric hospital outpatient waiting area: implications for infection control

BACKGROUND

Nosocomial outbreaks of viral etiology are costly and can have a major impact on patient care. Many viruses are known to persist in the inanimate environment and may pose a risk to patients and health care workers. We investigate the frequency of environmental contamination with common health care-associated viruses and explore the use of torque-teno virus as a marker of environmental contamination.

METHODS

Environmental screening for a variety of clinically relevant viruses was carried out over 3 months in a UK pediatric hospital using air sampling and surface swabbing. Swabs were tested for the presence of virus nucleic acid by quantitative polymerase chain reactions.

RESULTS

Viral nucleic acid was found on surfaces and in the air throughout the screening period, with adenovirus DNA being the most frequent. Door handles were frequently contaminated. Torque-teno virus was also found at numerous sites.

CONCLUSION

Evidence of environmental contamination with viral pathogens is present in health care environments and may be indicative of an infectious virus being present. Screening for viruses should be included in infection control strategies. Torque-teno virus may provide a better marker of contamination and reduce time and cost of screening for individual viruses.