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

Re-Emergence of HMPV in Gwangju, South Korea, after the COVID-19 Pandemic

The non-pharmaceutical interventions implemented to prevent the spread of COVID-19 have affected the epidemiology of other respiratory viruses. In South Korea, Human metapneumovirus (HMPV) typically occurs from winter to the following spring; however, it was not detected for two years during the COVID-19 pandemic and re-emerged in the fall of 2022, which is a non-epidemic season. To examine the molecular genetic characteristics of HMPV before and after the COVID-19 pandemic, we analyzed 427 HMPV-positive samples collected in the Gwangju area from 2018 to 2022. Among these, 24 samples were subjected to whole-genome sequencing. Compared to the period before the COVID-19 pandemic, the incidence rate of HMPV in 2022 increased by 2.5-fold. Especially in the age group of 6-10 years, the incidence rate increased by more than 4.5-fold. In the phylogenetic analysis results, before the COVID-19 pandemic, the A2.2.2 lineage was predominant, while in 2022, the A2.2.1 and B2 lineage were observed. The non-pharmaceutical interventions implemented after COVID-19, such as social distancing, have reduced opportunities for exposure to HMPV, subsequently leading to decreased acquisition of immunity. As a result, HMPV occurred during non-epidemic seasons, influencing the age distribution of its occurrences.

Burden of human metapneumovirus infections among children with acute respiratory tract infections attending a Tertiary Care Hospital, Kathmandu

BACKGROUND

Acute respiratory infections (ARIs) are one of the most common causes of mortality and morbidity worldwide. Every year millions of children suffer from viral respiratory tract infections (RTIs) ranging from mild to severe illnesses. Human Metapneumovirus (HMPV) is among the most frequent viruses responsible for RTIs. However, HMPV infections and their severity among children have not been explored yet in Nepal.

PURPOSE

Therefore, the study was focused on HMPV infections and other potential viral etiologies or co-infections using multiplex PCR among children attending Kanti Children's Hospital and assessed the clinical characteristics of the infections as well as found the co-infections. A hospital-based cross-sectional study was designed and a convenience sampling method was used to enroll children of less than 15 years with flu-like symptoms from both outpatients and inpatients departments over three months of the study period.

RESULTS

HMPV infection (13.3%) was the most predominant infection among the different viral infections in children with ARIs in Kanti Children's Hospital. The HMPV was more prevalent in the age group less than three years (21.8%). Cough and fever were the most common clinical features present in all children infected with HMPV followed by rhinorrhea, sore throat, and wheezing. HMPV-positive children were diagnosed with pneumonia (42.9%), bronchiolitis (28.5%), upper respiratory tract infections (14.3%), and asthma (14.3%). The prevalence of HMPV was high in late winter (14.3%) followed by early spring (13.5%).

CONCLUSIONS

This study provides the baseline information on HMPV and associated co-infection with other respiratory viruses for the differential diagnosis based on molecular methods and also the comparison of clinical presentations among the different respiratory syndromes.

Human metapneumovirus in hospitalized children with acute respiratory tract infections in Beijing, China

BACKGROUND

This study aims to described the epidemiology and genotypic diversity of Human metapneumovirus (HMPV) and the impact of SARS-CoV-2 on the prevalence of HMPV in hospitalized children with Acute respiratory tract infections (ARTIs) in Beijing, China.

METHODS

From April 2018 to March 2019 and from September 2020 to August 2021, nasopharyngeal aspirates (NPAs) from hospitalized children with ARTIs in Beijing were collected and subjected to real-time polymerase chain reaction tests for HMPV. Then genotyping, detection of 15 common respiratory viruses and clinical characteristics were analyzed on HMPV positive samples.

RESULTS

7.9% (124/1572) enrolled pediatric patients were identified as having HMPV infection, and the majority of children under the age of 5 (78.2%, 92/124), From April 2018 to March 2019. The detection rate of HMPV in spring and winter is significantly higher than that in summer and autumn. The co-infection rate were 37.1% (46/124), the most common co-infected virus were parainfluenza virus type 3 (HPIV-3). The main diagnosis of HMPV infection was pneumonia (92.7%,115/124), most patient have cough and fever. Of 78 HMPV-positive specimens, A2b (82.1%,64/78) were the main epidemic subtypes. Hospitalized children with HMPV genotype A infection had a higher viral load compared to genotype B. During the COVID-19 outbreak, Among 232 samples, only 4 cases were HMPV-positive. After statistical test, the detection rate of HMPV during the COVID-19 pandemic has decreased significantly compared with that before the epidemic (p = 0.001).

CONCLUSIONS

HMPV is an important cause of ARTIs in children under 5 years old. The epidemic peak is generally in winter and spring, and the A2b subtype is the most common. However, under the prevention and control of the COVID-19 pandemic, the HMPV infection of hospitalized children with ARTIs has decreased significantly.

Epidemiological and Clinical Characteristics of Respiratory Syncytial Virus Infections in Children Aged <5 Years in China, from 2014−2018

Respiratory syncytial virus (RSV) is an important pathogen that causes acute respiratory tract infections in children. To understand the epidemiological and clinical characteristics of RSV in children, we analyzed the RSV diagnostic testing results from the 2014−2018 surveillance of acute respiratory infections in China. Among children aged <5 years, RSV incidence during 2014−2018 was 17.3% (3449/19,898), and 89.1% of RSV-positive individuals were inpatients. Children aged < 6 months had a high proportion in RSV infected individual (n = 1234; 35.8%). The highest RSV detection rate was in winter, RSV-A and RSV-B co-circulated year-round and jointly prevailed in 2015−2016. Cough was the common symptom of RSV infection 93.2% (3216/3449). Compared with older children, those aged <6 months were more likely to show breathing difficulty or lung rale that further developed into bronchopneumonia (p < 0.001). The symptoms such as cough, running nose, and diarrhea had significant differences between the RSV-A and RSV-B groups. The rate of RSV co-detection with other viruses or bacteria was 35.4%. Those coinfected with other viruses had a significantly higher incidence of fever, whereas those coinfected with bacteria had higher incidences of breathing difficulty and severe pneumonia. Our findings highlight the need for accumulating epidemiological information for the prevention and control of RSV.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

Molecular typing and epidemiologic profiles of human metapneumovirus infection among children with severe acute respiratory infection in Huzhou, China

Background

Human metapneumovirus (hMPV) is one of the important pathogens in infant respiratory tract infection. However, the molecular epidemiology of hMPV among children < 14 years of age hospitalized with severe acute respiratory infection (SARI) is unclear. We investigated the hMPV infection status and genotypes of children hospitalized with SARI from January 2016 to December 2020 in Huzhou, China.

Methods

A nasopharyngeal flocked swab, nasal wash, or nasopharyngeal swab/or opharyngeal swab combination sample was collected from children with SARI in Huzhou from January 2016 to December 2020. Quantitative reverse transcription-polymerase chain reaction was performed to detect hMPV RNA. The hMPV F gene was amplified and sequenced, followed by analysis using MEGA software (ver. 7.0). Epidemiological data were analyzed using Microsoft Excel 2010 and SPSS (ver. 22.0) software.

Results

A total of 1133 children with SARI were recruited from 2016 to 2020. Among them, 56 (4.94%) were positive for hMPV-RNA. Children < 5 years of age accounted for 85.71% of the positive cases. The hMPV incidence was high in spring and winter, especially in December and January to March. Phylogenetic analysis of the F-gene sequences of 28 hMPV strains showed that the A1, B1, and B2 genotypes were prevalent in Huzhou, and the dominant hMPV genotype varied according to surveillance year.

Conclusions

HMPV is an important respiratory pathogen in children in Huzhou, with a high incidence in winter and spring in children < 5 years of age. In this study, genotypes A1, B1, and B2 were the most prevalent.

Human adenoviruses in paediatric patients with respiratory tract infections in Beijing, China

Background

Human adenoviruse (HAdV) is a major pathogen of paediatric respiratory tract infections (RTIs). Mutation or recombination of HAdV genes may cause changes in its pathogenicity and transmission. We described the epidemiology and genotypic diversity of HAdV in hospitalized children with RTIs in Beijing, China.

Methods

Nasopharyngeal aspirates were collected from hospitalized children with RTIs from April 2018 to March 2019. HAdVs were detected by a quantitative real-time PCR, and the hexon gene was used for phylogenetic analysis.

Results

Among 1572 samples, 90 (5.72%) were HAdV-positive. The HAdV detection rate was highest in November and July. Among HAdV-positive children, 61.11% (55/90) were co-infected with other respiratory viruses, the most common of which were human respiratory syncytial virus and human rhinovirus. The main diagnosis was bronchopneumonia, most patient have cough and fever. Children with a high viral load were more likely to have a high fever (P = 0.041) and elevated WBC count (P = 0.000). Of 55 HAdV-positive specimens, HAdV-B (63.64%), HAdV-C (27.27%), and HAdV-E (9.09%) were main epidemic species. Phylogenetic analysis indicated that hexon sequences of three samples were on the same branch with the recombinant HAdV strain (CBJ113), which was circulating in Beijing since 2016.

Conclusion

The HAdV-B3 and HAdV-B7 are the main epidemic strains in Beijing, and the recombinant HAdV-C strain CBJ113 has formed an epidemic trend.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-021-01661-6.

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

BACKGROUND

Acute 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.

METHODS

Hospitalized 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.

RESULTS

4.08% (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.

CONCLUSIONS

HMPV 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.

Human Metapneumovirus: Epidemiology and genotype diversity in children and adult patients with respiratory infection in Córdoba, Argentina

Human Metapneumovirus (hMPV) is responsible for acute respiratory infections in humans, with clinical and epidemiological relevance in pediatric, elderly, and immunocompromised populations. These features are largely unknown in Córdoba, Argentina and in adults in general. Hence, our goal was to broadly characterize hMPV infection in patients of all ages hospitalized with acute respiratory infections in Córdoba, Argentina, including epidemiology, clinical features and genetic diversity. Nasopharyngeal secretions were obtained from 795 patients during 2011-2013, 621 patients were 0-25 years old and 174 were 26-85 years old. HMPV was assayed by RT-PCR and other respiratory viruses by indirect immunofluorescence. Local strains were identified by sequence analysis. Human Metapneumovirus was detected in 20.3% (161/795) patients, 13.1% as single infections and 7.2% in co-infections, more frequently with Respiratory Syncytial Virus. HMPV circulated during late winter and spring in all age patients, but mainly in children under 4 years old in 71.4% (115/161) and adults between 26 and 59 years old in 12.4% (20/161). The most prevalent diagnosis was mild acute respiratory infection in 59.6% (96/161) and bronchiolitis in 9.3% (15/161). Local strains were clustered within A2 subtype; they presented 73-100% identities among them, showing a high degree of homology compared to isolations from neighboring countries. We demonstrate that hMPV circulated among all age patients with respiratory infection during 2011-2013 in Córdoba, contributing to the understanding of this virus, its diagnosis and patient handling in local health-care centers.

Epidemiological surveillance of common respiratory viruses in patients with suspected COVID-19 in Southwest China

BACKGROUND

The outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently the peak season of common respiratory viral infections. However, the clinical symptoms of most SARS-CoV-2 infected patients are not significantly different from those of common respiratory viral infections. Therefore, knowing the epidemiological patterns of common respiratory viruses may be valuable to improve the diagnostic and therapeutic efficacy of patients with suspected COVID-19, especially in Southwest China (a mild epidemic area).

METHODS

A total of 2188 patients with clinically suspected of COVID-19 in Southwest China were recruited from January 21 to February 29, 2020. Nasopharyngeal swabs, throat swabs and sputum specimens were collected to detect SARS-CoV-2 by using real-time reverse transcription-polymerase chain reaction (RT-PCR) and other 12 viruses via PCR fragment analysis combined with capillary electrophoresis. Clinical characteristics and laboratory test findings were acquired from electronic medical records. All data were analyzed to unravel the epidemiological patterns.

RESULTS

Only 1.1% (24/2188) patients with suspected COVID-19 were eventually confirmed to have SARS-CoV-2 infection, and the most frequently observed symptoms were fever (75.0%, 18/24) and cough (20.8%, 5/24). The overall detection rate of other respiratory pathogens was 10.3% (226/2188). Among them, human rhinovirus (3.2%, 71/2188), human parainfluenza viruses (1.6%, 35/2188), influenza B virus (1.2%, 26/2188) and mycoplasma pneumonia (1.2%, 26/2188) were the predominantly detected pathogens in this study. Moreover, the co-infection was observed in 22 specimens. Notably, one COVID-19 case had a coexisting infection with human parainfluenza virus (4.2%, 1/24) and bocavirus was the most common virus tending to occur in co-infection with other respiratory pathogens.

CONCLUSIONS

This study reveals the epidemiological features of common respiratory viruses and their clinical impact during the ongoing outbreak of COVID-19 in a mild epidemic area. The findings highlight the importance of understanding the transmission patterns of the common respiratory virus in COVID-19 regions, which can provide information support for the development of appropriate treatment plans and health policies, while eliminating unnecessary fear and tension.

Epidemiological characteristics of respiratory viruses in patients with acute respiratory infections during 2009-2018 in southern China

BACKGROUND

Acute respiratory infections (ARIs) remain a significant public threat with high morbidity and mortality worldwide; viruses are significant pathogens that cause ARIs. This study was conducted to better understand the epidemiological characteristics of respiratory viruses circulating in southern China.

METHODS

We collected 22,680 respiratory samples from ARI patients in 18 hospitals in southern China during 2009-2018; seven common respiratory viruses including Flu, RSV, PIV, hMPV, ADV, HCoV, and HBoV were screened using in-house real-time PCR.

RESULTS

Of all samples, 9760 ARI cases (9760/22680, 43.03%) tested positive for the seven common respiratory viruses. The most detected virus was Flu (14.15%), followed by RSV (10.33%) and PIV (5.43%); Flu-A, PIV3, and HCoV-OC43 were the predominant subtypes. Although most of the viruses were detected in male inpatients, Flu was more likely detected in female outpatients. Flu infection was more likely to cause URTI (upper respiratory tract infection), whereas RSV infection was more likely to cause pneumonia and bronchitis. The prevalence of Flu was particularly high in 2009. The epidemic level was found notably high in 2014-2018 for RSV, in 2016-2018 for PIV, in the summer of 2018 for ADV, in the summer of 2016 and winter of 2018 for HCoV, and in the summer of 2011 and autumn of 2018 for HBoV. The co-detection rate of the seven viruses was 4.70%; RSV, PIV, and Flu were the most commonly co-detected viruses.

CONCLUSIONS

This work demonstrates the epidemiological characteristics of seven common respiratory viruses in ARI patients in southern China.

Paramyxoviruses respiratory syncytial virus, parainfluenza virus, and human metapneumovirus infection in pediatric hospitalized patients and climate correlation in a subtropical region of southern China: a 7-year survey

To investigate the features of paramyxovirus respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (HMPV) infection and determine the effect of meteorological conditions in Guangzhou, a subtropical region of southern China. We collected 11,398 respiratory samples from hospitalized pediatric patients with acute respiratory illness between July 2009 and June 2016 in Guangzhou. The samples were tested simultaneously for 18 respiratory pathogens using real-time PCR. Local meteorological data were also collected for correlation analysis. Of 11,398 patients tested, 5606 (49.2%) patients tested positive for one or more pathogens; RSV, PIV, and HMPV were the first, sixth, and ninth most frequently detected pathogens, in 1690 (14.8%), 502 (4.4%), and 321 (2.8%) patients, respectively. A total 17.9% (4605/5606) of patients with positive results had coinfection with other pathogens. Significant differences were found in the prevalence of RSV, PIV, and HMPV among all age groups (p < 0.001). RSV and HMPV had similar seasonal patterns, with two prevalence peaks every year. PIV appeared alternatively with RSV and HMPV. Multiple linear regression models were established for RSV, PIV, and HMPV prevalence and meteorological factors (p < 0.05). RSV and PIV incidence was negatively correlated with monthly mean relative humidity; RSV and HMPV incidence was negatively correlated with sunshine duration; PIV incidence was positively correlated with mean temperature. We described the features of paramyxovirus infection in a subtropical region of China and highlighted the correlation with meteorological factors. These findings will assist public health authorities and clinicians in improving strategies for controlling paramyxovirus infection.

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.

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

Background

Acute 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.

Methods

A 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.

Results

Out 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).

Conclusions

Human 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.

Epidemiology, evolution and transmission of human metapneumovirus in Guangzhou China, 2013-2017

Human metapneumovirus (hMPV), first identified in 2001, is a major viral respiratory pathogen that worldwide reported. Fundamental questions concerning the dynamics of viral evolution and transmission at both regional and global scales remain unanswered. In this study, we obtained 32 G gene and 51 F gene sequences of hMPV in Guangzhou, China in 2013–2017. Temporal and spatial phylogenetic analyses were undertaken by incorporating publicly available hMPV G gene (978) and F gene (767) sequences. The phylogenetic results show different global distribution patterns of hMPV before 1990, 1990–2005, and 2006–2017. A sharply increasing hMPV positive rate (11%) was detected in Guangzhou 2017, mainly caused by the B1 lineage of hMPV. A close phylogenetic relation was observed between hMPV strains from China and Japan, suggesting frequent hMPV transmissions between these regions. These results provide new insights into hMPV evolution, transmission, and spatial distribution and highlight Asia as a new epicenter for viral transmission and novel variant seeding after the year 2005. Conducting molecular surveillance of hMPV in Asian countries is critical for understanding the global circulation of hMPV and future vaccine design.

Human adenovirus among hospitalized children with respiratory tract infections in Beijing, China, 2017-2018

BACKGROUND

Human adenoviruses (HAdVs) cause a wide range of diseases. However, the genotype diversity and epidemiological information relating to HAdVs among hospitalized children with respiratory tract infections (RTIs) is limited. Here, we describe the epidemiology and genotype distribution of HAdVs associated with RTIs in Beijing, China.

METHODS

Nasopharyngeal aspirates (NPA) were collected from hospitalized children with RTIs from April 2017 to March 2018. HAdVs were detected by a TaqMan-based quantitative real-time polymerase chain reaction (qPCR) assay, and the hexon gene was used for phylogenetic analysis. Epidemiological data were analyzed using statistical product and service solutions (SPSS) 21.0 software.

RESULTS

HAdV was detected in 72 (5.64%) of the 1276 NPA specimens, with most (86.11%, 62/72) HAdV-positives cases detected among children < 6 years of age. HAdV-B3 (56.06%, 37/66) and HAdV-C2 (19.70%, 13/66) were the most frequent. Of the 72 HAdV-infected cases, 27 (37.50%) were co-infected with other respiratory viruses, most commonly parainfluenza virus (12.50%, 9/72) and rhinovirus (9.72%, 7/72). The log number of viral load ranged from 3.30 to 9.14 copies per mL of NPA, with no significant difference between the HAdV mono- and co-infection groups. The main clinical symptoms in the HAdV-infected patients were fever and cough, and 62 (86.11%, 62/72) were diagnosed with pneumonia. Additionally, HAdVs were detected throughout the year with a higher prevalence in summer.

CONCLUSIONS

HAdV prevalence is related to age and season. HAdV-B and HAdV-C circulated simultaneously among the hospitalized children with RTIs in Beijing, and HAdV-B type 3 and HAdV-C type 2 were the most frequent.

Beyond Respiratory Syncytial Virus and Rhinovirus in the Pathogenesis and Exacerbation of Asthma: The Role of Metapneumovirus, Bocavirus and Influenza Virus

Respiratory viruses other than rhinovirus or respiratory syncytial virus, including human metapneumovirus, influenza virus, and human bocavirus, are important pathogens in acute wheezing illness and asthma exacerbations in young children. Whether infection with these viruses in early life is associated with recurrent wheezing and/or asthma is not fully investigated, although there are data to suggest children with human metapneumovirus lower respiratory tract infection may have a higher likelihood of subsequent and recurrent wheezing several years after initial infection.