Agents Of Acute Respiratory Infections Research Articles

Clinical characteristics and viral etiologies of outpatients with acute respiratory infections in Huzhou of China: a retrospective study

BackgroundViruses are commonly found in patients with acute respiratory infections (ARIs). However, the viral etiologies and clinical characteristics of outpatients with ARIs are poorly understood in China. Here, we identified the viral etiologies in outpatients with ARIs in Huzhou, China.ResultsOur results indicated that of 426 outpatients, 246 were positive for viruses. Of them, 221 were positive for a single virus, including influenza A, which comprised H3N2 (28.5%) and pandemic H1N1 (2009) (19.0%), enterovirus (10.4%), and influenza B (8.6%). Other single viruses were detected at less than 8.0%. Twenty-five patients were positively coinfected with two viruses. The prevalent viruses in coinfections were rhinovirus and H3N2 virus (28.0%). Viruses were major pathogens in young children (< 5 years) (75.0%). Coinfections were prevalent in older adults (11.9%) and young children (9.5%). Virus-positive outpatients presented higher temperatures and more sore throat, fatigue and shortness of breath than virus-negative outpatients. ARIs and most virus detections peaked during the winter, but enteroviruses emerged between April and September.ConclusionViruses are major agents of ARIs among outpatients in Huzhou, China. There was a variation in the distribution of viruses across different age groups and seasons. These findings are beneficial for planning prevention and treatment services for outpatients with ARIs.

Predominant Detection of the Subgroup A2b Human Metapneumovirus Strain with a 111-Nucleotide Duplication in the G gene in Yokohama City, Japan in 2018.

Human metapneumovirus (HMPV) has been a major causative agent of acute respiratory infections in humans. Recently, two types of variant A2b subtype HMPV strains possessing a 111- or 180-nucleotide duplication (nt-dup) in the G gene (HMPV A2b180nt-dup and HMPV A2b111nt-dup, respectively) were detected in Japan, Spain, Vietnam, and China. Our surveillance for infectious agents in Yokohama City, Japan revealed that the HMPV A2b111nt-dup strain became predominant in Yokohama City in 2018. In contrast, no classic HMPV A2b strain was detected after 2017. These data indicate a beneficial role of the 111nt-dup in the G gene for the transmission of HMPV.

Acute Respiratory Infection by Chlamydophila pneumoniae and Mycoplasma pneumoniae in a Population of Older Adults in Colombia

&lt;p&gt;&lt;strong&gt;Abstract&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Introduction:&lt;/strong&gt; Acute Respiratory Infection (ARI) is a heterogeneous group of viral and bacterial respiratory pathologies including &lt;em&gt;Chlamydophila pneumoniae&lt;/em&gt; (CP) and &lt;em&gt;Mycoplasma pneumoniae&lt;/em&gt; (MP) that are not routinely identified; these infections in the older adults have mortality rates 3 to 5 times higher than that recorded in other age groups. &lt;strong&gt;Methods:&lt;/strong&gt; this study was conducted prospectively to determine the proportion of atypical bacterial pathogens in older adults with ARI in Bogotá. Microbiological diagnosis was determined by real-time PCR (qPCR) in samples of respiratory origin and serology for antibodies IgG, IgA and IgM to MP and CP. &lt;strong&gt;Results:&lt;/strong&gt; A total of 71 patients were enrolled from 2012 to 2013. Upper respiratory infections were diagnosed in the 69% of patients and lower respiratory infections in 31%. MP was identified in 9.8% and CP in 8.5%. &lt;strong&gt;Conclusions:&lt;/strong&gt; these findings indicated that CP and MP must be viewed as a significant etiological agent of ARI in older adults in Bogotá.&lt;/p&gt;

Distinct genetic clades of enterovirus D68 detected in 2010, 2013, and 2015 in Osaka City, Japan.

The first upsurge of enterovirus D68 (EV-D68), a causative agent of acute respiratory infections (ARIs), in Japan was reported in Osaka City in 2010. In this study, which began in 2010, we surveyed EV-D68 in children with ARIs and analyzed sequences of EV-D68 strains detected. Real-time PCR of 19 respiratory viruses or subtypes of viruses, including enterovirus, was performed on 2,215 specimens from ARI patients (<10 years of age) collected between November 2010 and December 2015 in Osaka City, Japan. EV-D68 was identified in 18 enterovirus-positive specimens (n = 4 in 2013, n = 1 in 2014, and n = 13 in 2015) by analysis of viral protein 1 (VP1) or VP4 sequences, followed by a BLAST search for similar sequences. All EV-D68 strains were detected between June and October (summer to autumn), except for one strain detected in 2014. A phylogenetic analysis of available VP1 sequences revealed that the Osaka strains detected in 2010, 2013, and 2015 belonged to distinct clusters (Clades C, A, and B [Subclade B3], respectively). Comparison of the 5′ untranslated regions of these viruses showed that Osaka strains in Clades A, B (Subclade B3), and C commonly had deletions at nucleotide positions 681–703 corresponding to the prototype Fermon strain. Clades B and C had deletions from nucleotide positions 713–724. Since the EV-D68 epidemic in 2010, EV-D68 re-emerged in Osaka City, Japan, in 2013 and 2015. Results of this study indicate that distinct clades of EV-D68 contributed to re-emergences of this virus in 2010, 2013, and 2015 in this limited region.

Detection of Saffold viruses from children with acute respiratory infections in Yamagata, Japan, between 2008 and 2015.

Although Saffold virus (SAFV) was reported as a novel human cardiovirus in 2007, no causative association between SAFV and clinical disease has been proven and the longitudinal epidemiology of SAFVs is not available. To establish the relationship between SAFVs and acute respiratory infections (ARIs) and to clarify the longitudinal epidemiology of SAFVs, 7258 nasopharyngeal specimens were collected from children with ARIs in Yamagata, Japan between 2008 and 2015. The specimens were inoculated on a microplate including six cell lines as part of routine surveillance, and molecular screening was performed for SAFVs using a reverse transcription (RT)-PCR method. Throughout the study period, 95 (1.3%) SAFV genotype 2 (SAFV2), and 28 (0.4%) SAFV3 were detected, mainly between September and November. There were two outbreaks of SAFV2 in 2009 and 2013, and one outbreak of SAFV3 in 2012 and the positive rates during these outbreaks were 12.1% (53/439), 11% (35/319), and 4.4% (20/453), respectively. Sixty-three SAFV2 and 28 SAFV3 strains were detected as a single virus from children with ARIs such as pharyngitis, herpangina, and tonsillitis. These results suggested that SAFV2 and SAFV3 are possible causative agents of ARIs among children and their infections occur mainly in the autumn season in Japan.

Human Rhinovirus Association with Influenza-Like Illness and Symptomatic Treatment for Acute Respiratory Infection in a Brazilian Southern City

Acute respiratory infections (ARI) are the world’s leading cause of morbidity and mortality. ARI impairs children’s education and have a huge impact on the economy. Human rhinovirus (HRV) is the most prevalent agent of ARI. In this study, a clinical and epidemiological surveillance in outpatients was carried to investiga-te the involvement of HRV in ARI cases in the city of Guarapuava, a Brazilian southern city. Attention was also given to the most common medications used for treating ARI symptoms. Samples from 135 patients were col-lected from Apr to Dec from 2014, HRV was identified in nearly 20% of samples, with symptoms ranging from common cold to Influenza-like Illness (ILI) and was more frequent in individuals with 10 or less years-old. Ne-arly two thirds of patients reported use of at least one class of drug during the ARI episodes, such as analgesi-cs, cough and cold preparations, and NSAIDs. In some cases and with no justifiable reason, patients also repor-ted the use of antibiotics, possibly contributing to the development of bacterial resistance. These results show a significant detection rate of HRV in ARI cases, and highlight the impact of this virus in the local population.

Atypical bacterial etiology of acute respiratory infections and clinical characterizations among Iranian children.

Acute respiratory infections (ARIs) in children younger than 5 years of age are one of the leading causes of morbidity and mortality, particularly in developing countries. Mycoplasma pneumoniae and Chlamydophila pneumoniae are prevalent causative agents of ARIs, worldwide. We sought M. pneumoniae and C. pneumoniae in respiratory samples from Iranian children with ARIs. From November 2014 to April 2015, respiratory samples of 150 children aged 1 month to 15 years old were screened for presence of M. pneumoniae and C. pneumoniae. Polymerase chain reaction (PCR) and culture methods were used to detect these bacteria in respiratory samples in the form of throat swabs and nasopharyngeal aspirates. A questionnaire containing demographic and clinical information has been filled up for all participants in this study. Our obtained data showed that out of 150 tested samples, 7 (4.7%) were PCR positive for M. pneumoniae and only one (0.7%) positive sample for C. pneumoniae was detected. However, none of the tested samples was detected M. pneumoniae using the bacterial culture method. All patients with ARIs due to M. pneumoniae showed up with sore throat and flu like symptoms. According to our data, PCR method is more sensitive than culture for detection of M. pneumoniae. With regards to our results, it appears that M. pneumoniae and especially C. pneumoniae were infrequent causative agents in our studied population.

180-Nucleotide Duplication in the G Gene of Human metapneumovirus A2b Subgroup Strains Circulating in Yokohama City, Japan, since 2014.

Human metapneumovirus (HMPV), a member of the family Paramyxoviridae, was first isolated in 2001. Seroepidemiological studies have shown that HMPV has been a major etiological agent of acute respiratory infections in humans for more than 50 years. Molecular epidemiological, genetic, and antigenetic evolutionary studies of HMPV will strengthen our understanding of the epidemic behavior of the virus and provide valuable insight for the control of HMPV and the development of vaccines and antiviral drugs against HMPV infection. In this study, the nucleotide sequence of and genetic variations in the G gene were analyzed in HMPV strains prevalent in Yokohama City, in the Kanto area, Japan, between January 2013 and June 2016. As a part of the National Epidemiological Surveillance of Infectious Diseases, Japan, 1308 clinical specimens (throat swabs, nasal swabs, nasal secretions, and nasal aspirate fluids) collected at 24 hospitals or clinics in Yokohama City were screened for 15 major respiratory viruses with a multiplex reverse transcription–PCR assay. HMPV was detected in 91 specimens, accounting for 7.0% of the total specimens, and the nucleotide sequences of the G genes of 84 HMPV strains were determined. Among these 84 strains, 6, 43, 10, and 25 strains were classified into subgroups A2a, A2b, B1, and B2, respectively. Approximately half the HMPV A2b subgroup strains detected since 2014 had a 180-nucleotide duplication (180nt-dup) in the G gene and clustered on a phylogenic tree with four classical 180nt-dup-lacking HMPV A2b strains prevalent between 2014 and 2015. The 180nt-dup causes a 60-amino-acid duplication (60aa-dup) in the G protein, creating 23–25 additional potential acceptor sites for O-linked sugars. Our data suggest that 180nt-dup occurred between 2011 and 2013 and that HMPV A2b strains with 180nt-dup (A2b180nt-dup HMPV) became major epidemic strains within 3 years. The detailed mechanism by which the A2b180nt-dup HMPV strains gained an advantage that allowed their efficient spread in the community and the effects of 60aa-dup on HMPV virulence must be clarified.

Biophysical characterization of the interaction between M2-1 protein of hRSV and quercetin

hRSV is the major causative agent of acute respiratory infections. Among its eleven proteins, M2-1 is a transcription antiterminator, making it an interesting target for antivirals. Quercetin is a flavonol which inhibits some virus infectivity and replication. In the present work, the M2-1 gene was cloned, expressed and the protein was purified. Thermal stability and secondary structure were analyzed by circular dichroism and the interaction with Quercetin was evaluated by fluorescence spectroscopy. Molecular docking experiments were performed to understand this mechanism of interaction. The purified protein is mainly composed of α-helix, with a melting temperature of 328.6K (≈55°C). M2-1 titration with Quercetin showed it interacts with two sites, one with a strong constant association K1 (site 1≈1.5×106M−1) by electrostatic interactions, and another with a weak constant association K2 (site 2≈1.1×105M−1) by a hydrophobic interaction. Ligand’s docking shows it interacts with the N-terminus face in a more polar pocket and, between the domains of oligomerization and RNA and P protein interaction, in a more hydrophobic pocket, as predicted by experimental data. Therefore, we postulated this ligand could be interacting with important domains of the protein, avoiding viral replication and budding.

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).

Acute and Recurrent Respiratory Tract Infections: Possible Reduction of the Patient’s Pill Burden

Acute and recurrent respiratory tract infections in children are often the reason for seeking medical help. Frequent and prolonged respiratory infections in childhood may lead to the subsequent formation of chronic respiratory diseases in adults. Susceptibility to respiratory infections is common in children with allergic diseases and other chronic diseases accompanied by a decrease in immune reactivity. In the case of acute respiratory infection, these patients, in addition to the basic treatment of the underlying disease, have to take additional cough medicines that increase the pill burden on the body. The main causative agents of acute respiratory infections are viruses. Inosine pranobex is a drug with antiviral and immunomodulatory effects. The article describes the pharmacological properties and the results from studying the efficacy of inosine pranobex in the treatment of acute respiratory viral infections in children.

Clinical presentations ofChlamydia pneumoniaein children hospitalized for acute respiratory infections: a comparison toMycoplasma pneumonia

Purpose: Chlamydia pneumoniae is a common intracellular bacterial pathogen and plays an important role in acute respiratory infections. The purpose of this study was to investigate clinical presentations of C. pneumoniae in children with acute respiratory infections. Methods: We examined the medical records of pediatric patients (age<18 years) admitted with acute respiratory infections of C. pneumoniae to Gachon University Gil Medical Center between March 1, 2011 and August 31, 2014. We compared the clinical features of C. pneumoniae infection with that of Mycoplasma pneumoniae infection. Results: We confirmed acute respiratory infections of C. pneumoniae in 110 patients out of 2,156 patients (5.1%) admitted with acute respiratory infections. The mean age was 37.2±30.1 months. More than half of them (54.5%) had coinfection. C. pneumoniae infection had mild and subacute courses. The mean duration of symptoms prior to admission was 8.5±13.8 days. There were remarkable seasonal variations and prevalence was higher in December and April (P=0.03 and P=0.02, respectively). Although rhinorrhea and pharyngeal injection were more common in C. pneumoniae infection (P<0.05), clinical signs and symptoms were similar between C. pneumoniae and M. pneumoniae. Extrapulmonary manifestations such as skin lesion, Gastrointestinal symptoms, hepatitis, and neurologic symptoms were common (41.0%) in C. pneumoniae infection and, had similar incidence in M. pneumoniae infection. Conclusion: C. pneumoniae is an important infectious agent of acute respiratory infections in children. Clinical pictures of C. pneumoniae are similar to M. pneumoniae, even in extrapulmonary manifestations. C. pneumoniae should be taken into consideration in differential diagnosis of acute respiratory infection in children. (Allergy Asthma Respir Dis 2015;3:346-351)

Effect of Human Beta Defensin-2 in Epithelial Cell Lines Infected with Respiratory Viruses

β-defensins are a family of antimicrobial molecules involved in inflammatory processes and infections. In human airways, β-defensin-2 (hβD-2) is the best characterized in bacterial and fungal infections; however, it has been insufficiently studied in viral infections. The respiratory syncytial virus (RSV) and adenoviruses (ADV) are important agents of acute respiratory infections. The aim of this study was to measure in vitro the production and antiviral activity of hβD-2 in HEp-2 cells and A549 cells infected with ADV and RSV; hβD-2 production at different times was assessed by RT-PCR, and its presence by immunodetection assay (Western blot) using antibodies anti-hβD-2. The effect of this defensin on viral replication was determined using recombinant hβD-2 in plaque assays. The results revealed that in the cell lines production of hβD-2is up regulated after ADV or RSV infection, in direct proportion to the exposure time to each virus. The use of a high concentration of recombinant hβD-2 resulted in less deleterious viral effect on the cells. The results suggest that both viruses induce hβD-2 production, no matter if the virus is enveloped or not, and that presence of hβD-2 reduces replication and cytopathic in vitro effect of RSV and ADV. The hβD-2 production by low pathogenicity viruses or live viral vaccines can be useful as therapeutic tools in some infectious diseases.

Frequent respiratory viral infections in a young child in a 27-month follow-up study.

Introduction:Viruses are major aetiological agents of acute respiratory infection in young children. Although many studies have reported detection and analysis of respiratory viruses in sporadic cases, there have been few follow-up studies of individuals. The purpose of this study was to investigate the frequency of respiratory viral infections in a young child and to examine the duration of viral genome detection in clinical specimens.Case presentation:A total of 284 nasal swabs were collected during symptomatic (196 specimens) and asymptomatic (88 specimens) periods of respiratory symptoms from a young female child (from 4 months to 31 months of age, who was admitted to a nursery school at 9 months). Multiplex real-time PCR for 19 respiratory viruses or subtypes was performed. One hundred and ninety-eight of the tested specimens were virus positive (69.7 %) (symptomatic periods, 149/196, 76.0 %; asymptomatic periods, 49/88, 55.7 %). Rhinovirus was the most frequently detected (26 times). Long durations of detection were observed for human coronavirus NL63 (30 days), rhinovirus (28 days) and human bocavirus 1 (22 days).Conclusion:Young children living in a group context have a high risk of respiratory virus infections, especially rhinovirus. In some instances, viral genomes were detectable for about 1 month by PCR.

Chlamydophila pneumoniae, Mycoplasma pneumoniae, and influenza in children with respiratory infections in Alexandria, Egypt

Acute respiratory infections (ARI) are the leading cause of pediatric morbidity and mortality worldwide. Information about etiological agents of ARI in developing countries is still limited. Throat swabs collected from children hospitalized with ARI between December 2009 and May 2010 were investigated for Chlamydophila pneumoniae, Mycoplasma pneumoniae, and influenza viruses by molecular analyses. This study conducted in Alexandria, Egypt, was designed to determine the prevalence of several microorganisms in 156 children hospitalized with ARI. Overall, samples from 76 individuals (49%) were found to be positive for at least one pathogen, and 10 of them were positive for two agents. C. pneumoniae was the most commonly detected agent, followed by M. pneumonia and H1N1 pandemic influenza virus. Positivity for C. pneumoniae was associated with colder months and mild disease of the upper respiratory tract such as laryngitis. Further studies are needed to identify other possible agents of ARI (e.g., RSV, adenoviruses, other bacterial infections) in this population and to better understand the causal role of atypical bacteria detected in respiratory samples.

Associations between co-detected respiratory viruses in children with acute respiratory infections.

Viruses are the major etiological agents of acute respiratory infections (ARIs) in young children. Although respiratory virus co-detections are common, analysis of combinations of co-detected viruses has never been conducted in Japan. Nineteen respiratory viruses or subtypes were surveyed using multiplex real-time PCR on 1,044 pediatric (patient age < 6 years) ARI specimens collected in Osaka City, Japan between January 2010 and December 2011. In total, 891 specimens (85.3%) were virus positive (1,414 viruses were detected), and 388 of the virus-positive specimens (43.5%, 388/891) were positive for multiple viruses. The ratio of multiple/total respiratory virus-positive specimens was high in children aged 0-35 months. Statistical analyses revealed that human bocavirus 1 and human adenovirus were synchronously co-detected. On the other hand, co-detections of human parainfluenza virus type 1 (HPIV-1) with HPIV-3, HPIV-3 with human metapneumovirus (hMPV), hMPV with respiratory syncytial virus A (RSV A), hMPV with influenza virus A (H1N1) 2009 (FLUA (H1N1) 2009), RSV A with RSV B, and human rhinovirus and FLUA (H1N1) 2009 were exclusive. These results suggest that young children (<3 years) are highly susceptible to respiratory viruses, and some combinations of viruses are synchronously or exclusively co-detected.

Epidemiology of parainfluenza virus types 1, 2 and 3 infections based on virus isolation between 2002 and 2011 in Yamagata, Japan

To clarify the epidemiology of viral acute respiratory infections (ARIs), 305 human parainfluenza virus types 1 (HPIV1), 154 HPIV2 and 574 HPIV3 strains were isolated from 16,962 nasopharyngeal swabs obtained between 2002 and 2011 at pediatric clinics in Yamagata, Japan. The total isolation frequency for HPIV1-3 was 6.1%. Unlike HPIV1 infections, HPIV3 showed clear seasonality with yearly outbreaks in the spring-summer season. HPIV2 tended to appear biannually in autumn-winter. Although no reliable techniques for the laboratory diagnosis of these infections have been established, the present results suggest that HPIV1-3 are an important causative agent of ARIs in children.

Incidence of respiratory viruses in a pediatric population: molecular and epidemiological aspects

Introduction: Respiratory infections are not well defined and the etiology is often unknown. Material and method: four hundred fortynine subjectrs were enrolled in the study; in all patientes there was a suspect of inflammatory diseases of the respiratory tract. At admission, a nasopharyngeal swab was made. A multiplex PCR was performed after extraction and reverse transcription of viral RNA. The amplified fragments were revealed by using an electrophoresis separation. Results: Two hundred and four patients (45.4%) were hospitalized for infection of the upper respiratory tract, 141 (31.4%) for lower respiratory infection and the remaining (23%) for other symptoms. One hundred fiftyseven (35%) patients were positive for human influenza A (H1N1 subtype) and 184 for other respiratory viruses,of which 59 (32%) gave a positive for respiratory syncytial virus, 42 (23%) for rhinovirus, 31 (17%) for parainfluenza virus, 12 (6.5%) for coronavirus, 28 (15%) for adenovirus and 6 (3%) for influenza B (3%) and 6 (3%) for metapneumovirus. The M1 gene sequence of influenza A H1N1 strains from 12 patients had a high identity with that of the reference virus. Conclusion: Furthermore H1N1 and RSV were the main causative agents of acute respiratory infection. A molecular approach provides an accurate and rapid aetiological diagnosis of viral respiratory infections. The molecolar features in the M1 gene suggested that the H1N1 influenza strains circulating in Apulia region had a conserved genetic make up.

Impact of human metapneumovirus infection on in and outpatients for the years 2006-2008 in Southern Brazil

The human metapneumovirus (hMPV), member of the Paramyxoviridae family, has been reported as an important agent involved with acute respiratory infections (ARIs). The aim of this study is to identify hMPV as the etiological agent of ARIs on in and outpatients in the city of Curitiba, Southern Brazil, and describe clinical data of hMPV subtyping. A retrospective study was performed in 1,572 respiratory samples over a period of three years. hMPV was detected by reverse transcription-polymerase chain reaction and subtyping was performed by nucleotide sequencing. hMPV was present in 61 (3.9%) samples and subtypes A1, A2a, B1 and B2 were detected. The incidence of hMPV was higher in outpatients (5.9%), whose mean age was 19.7 years (range 6 months-75 years old), than in inpatients (3%), whose mean age was 7.6 months (range 1 month-26 years old). The outpatients had upper respiratory tract infections with flu-like symptoms and all hospitalized children had lower respiratory tract infections. A pediatric patient died from complications associated with hMPV A2a infection. hMPV has been reported as a respiratory pathogen in all age groups. No correlation was observed between viral subtype and disease severity in the samples of this study.

The Role of Human Metapneumovirus in Pediatric Respiratory Tract Infection in Qatar

Aim: The human metapneumovirus (hMPV) has been recently discovered as an etiological agent of acute respiratory infections in infants and children, with similar clinical symptoms to those caused by respiratory syncytial virus. The aim of this study was to determine the prevalence of hMPV and its potential role as a causative agent of respiratory tract infections in children in Qatar. Methods: In the present study, we examined 84 nasopharyngeal aspirates from children with respiratory tract infections, presenting at Al-Saad Pediatric Emergency Center in Doha, Qatar, as outpatients, for the presence of respiratory viruses. Results: A total of 56 out of 84 (66.7%) cases were positive for the presence of respiratory viruses. Out of the 56 positive cases 54 (96%) contained hMPV; whereas 12 out of 56 (21.4%) contained human parainfluenza virus. A total of 14 out of 56 of the positive patients were infected with more than one virus. hMPV was in samples infected with one or more respiratory tract infection viruses and was the most frequently isolated virus from infants less than 6 months of age. Conclusion: This is the first report demonstrating the prevalence of hMPV in children suffering from respiratory tract infections in Qatar. Detection of this virus may have significant clinical implications in this patient population in Qatar.