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

Increased risk during winter: common respiratory viruses and clinical outcomes in hospitalized children

BACKGROUND

Acute respiratory infections (ARIs) are a leading cause of hospitalisation, severe morbidity, and mortality in children, representing a significant public health concern. This study aimed to evaluate the clinical features, laboratory findings, and outcomes of pediatric patients hospitalised due to ARIs caused by common respiratory viruses, including influenza virüs (IFV), human bocavirus (hBoV), human metapneumovirus(hMPV), human rhinovirus (hRV), and human respiratory syncytial virüs (hRSV).

METHODS

We conducted a retrospective analysis of 1465 hospitalized pediatric patients at Ankara Bilkent City Hospital Children's Hospital between August 2019 and March 2024. Nasopharyngeal swabs were analyzed using multiplex real-time PCR to identify viral pathogens. Clinical data, including demographics, intensive care needs, respiratory support, and chronic health conditions, were reviewed.

RESULTS

A total of 1465 hospitalized children were included in the study, with a median age of 3 years and 61.8% being male. Of these patients, 32.9% (n = 482) had chronic health conditions. IFV was detected in 30.1% of patients, hBoV in 28.3%, hRSV in 18.4%, hRV in 14.4%, and hMPV in 8.8%. Over half of the infections occurred during the winter months, with IFV being the most commonly observed virus. Fever was most frequently observed in IFV cases, while cough and hypoxia were more prevalent in hBoV and hRSV infections. Admission to the Pediatric Intensive Care Unit was necessary in 19.5% of cases, with 33.1% of these requiring invasive mechanical ventilation. Invasive mechanical ventilation was most frequently required in hBoV cases. The mortality rate was 8.7%, predominantly observed in patients with chronic health conditions; hBoV was associated with the highest mortality.

CONCLUSION

This study provides a comprehensive analysis of the clinical, laboratory, and radiological characteristics of children hospitalized due to viral lower respiratory tract infections, offering valuable insights into common respiratory pathogens. The findings underscore a higher incidence of these infections during the winter months. It is recommended that hBoV and IFV infections be closely monitored in children with underlying chronic conditions. Moreover, the study highlights the importance of meticulous management of hBoV and hRSV infections, given their association with an increased need for intensive care support.

Epidemiological characteristics of five non-COVID respiratory viruses among 37,139 all-age patients during 2018 - 2023 in Weifang, China: a cross-sectional study

BACKGROUND

Common non-COVID respiratory viruses, such as influenza virus (IFVA/IFVB), parainfluenza virus (PIV), respiratory syncytial virus (RSV), and adenovirus (ADV), often cause acute respiratory infections (ARIs). This study aimed to explore the epidemiological characteristics of these five viruses in patients with ARIs before, during, and after the COVID-19 pandemic from 2018 to 2023.

METHODS

A total of 37,139 serum specimens and epidemiological data from all-aged patients who presented with ARIs were collected from January 2018 to December 2023. The IgM antibodies of five non-COVID respiratory viruses were tested by an IgM kit with indirect immunofluorescent assay (lFA).

RESULTS

12,806 specimens were screened as positive for any one of the targeted viruses, with an overall positivity rate of 34.48%. Among all age groups, the most prevalent respiratory viruses were PIV (21.30%) and influenza virus (17.30% of IFVB and 9.91% of IFVA). Children aged 1-14 years were most vulnerable to lower respiratory viruses, and children aged 4-6 years have the highest prevalence no matter the positivity rate for overall viruses (53.06%) or for each virus. From 2018 to 2023, the annual percentage change (APC) revealed that the prevalence of total viruses have a 13.53% rise (p < 0.05), which increased with statistically significant for all age groups. In addition, both the infection rate and the number of samples detected have decreased significantly in the "first-level response" stage of the COVID-19 pandemic and in the "first three months" after fully lifted. Compared to those in the previous five years, the total infection rate (44.64%) and infection rate (26.93%) of the older adults (> 60 years) were all the highest in 2023, and the number of samples collected in 2023 sharply increased, increasing by 77.10% compared to the average of the number of detected in 2018-2022.

CONCLUSIONS

The data from this study indicate that the epidemiological characteristics of five non-COVID respiratory viruses are vulnerability to the environment, age, sex, and epidemics status among AIR patients, and that the detected number and positivity rate of these viruses have increased in the "post-pandemic era", which is critical for the late or retrospective diagnosis and can serve as a useful surveillance tool to inform local public policy in Weifang, China.

Viral etiology of febrile respiratory syndrome among patients in Liaoning Province, China

BACKGROUND

Febrile respiratory syndrome (FRS) is often associated with viral infections. The aim of this study was to identify the viral pathogens responsible for FRS in Liaoning Province, China.

METHODS

We tested eight respiratory viruses, namely, influenza virus (IFV), rhinovirus (RV), human adenovirus (HAdV), human bocavirus (HBoV), human parainfluenza virus (HPIV), human coronavirus (HCoV), respiratory syncytial virus (RSV), and human metapneumovirus (HMPV), using reverse transcription-polymerase chain reaction (RT-PCR). Statistical analyses were performed using SPSS version 25.0, and the data were plotted using RStudio 4.2.1 software.

RESULTS

IFV was the most frequently identified pathogen, followed by RV, HAdV, HBoV, HPIV, HCoV, RSV, and HMPV. RSV/HBoV coinfection occurred most frequently among the mixed cases. The rate of respiratory virus detection was highest in children under one year of age and decreased significantly with age. Seasonal trends showed a peak in virus detection during the winter months.

CONCLUSIONS

IFV is the leading cause of FRS in Liaoning Province, China, with single-virus infections prevailing over coinfections. Observations indicate a differential virus detection rate across age groups and seasons, highlighting the need for focused preventive strategies to mitigate the transmission of respiratory viruses, particularly among susceptible populations in the colder season.

Genetic diversity and molecular analysis of human influenza virus among pilgrims during Hajj

The risk of transmission of respiratory tract infections is considerably enhanced at mass gathering (MG) religious events. Hajj is an annual Islamic MG event with approximately 3 million Muslim pilgrims from over 180 countries concentrated in Makkah, Saudi Arabia. This study aimed to investigate the genetic diversity of influenza viruses circulating among pilgrims during the Hajj pilgrimage. We performed a cross-sectional analytical study where nasopharyngeal swabs (NPs) from pilgrims with respiratory tract illnesses presenting to healthcare facilities during the 2019 Hajj were screened for influenza viruses. Influenza A subtypes and influenza B lineages were determined by multiplex RT-PCR for positive influenza samples. The phylogenetic analysis was carried out for the hemagglutination (HA) gene. Out of 185 nasopharyngeal samples, 54 were positive for the human influenza virus. Of these, 27 were influenza A H1N1 and 19 H3N2, 4 were untypable influenza A, and 4 were influenza B. Phylogenetic analysis revealed that the H1N1 and H3N2 strains differentiated into different and independent genetic groups and formed close clusters with selected strains of influenza viruses from various locations. To conclude, this study demonstrates a high genetic diversity of circulating influenza A subtypes among pilgrims during the Hajj Season. There is a need for further larger studies to investigate in-depth the genetic characteristics of influenza viruses and other respiratory viruses during Hajj seasons.

A cooperativity between virus and bacteria during respiratory infections

Respiratory tract infections remain the leading cause of morbidity and mortality worldwide. The burden is further increased by polymicrobial infection or viral and bacterial co-infection, often exacerbating the existing condition. Way back in 1918, high morbidity due to secondary pneumonia caused by bacterial infection was known, and a similar phenomenon was observed during the recent COVID-19 pandemic in which secondary bacterial infection worsens the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) condition. It has been observed that viruses paved the way for subsequent bacterial infection; similarly, bacteria have also been found to aid in viral infection. Viruses elevate bacterial infection by impairing the host's immune response, disrupting epithelial barrier integrity, expression of surface receptors and adhesion proteins, direct binding of virus to bacteria, altering nutritional immunity, and effecting the bacterial biofilm. Similarly, the bacteria enhance viral infection by altering the host's immune response, up-regulation of adhesion proteins, and activation of viral proteins. During co-infection, respiratory bacterial and viral pathogens were found to adapt and co-exist in the airways of their survival and to benefit from each other, i.e., there is a cooperative existence between the two. This review comprehensively reviews the mechanisms involved in the synergistic/cooperativity relationship between viruses and bacteria and their interaction in clinically relevant respiratory infections.

Viral metagenomics of pharyngeal secretions from children with acute respiratory diseases with unknown etiology revealed diverse viruses

Acute respiratory tract infections are a major public health problem and the leading cause of morbidity in children younger than 5 years old. This study investigated the potential reasons of unexplained acute respiratory infections in children in Xuzhou and its environs during 2018-2019.We collected pharyngeal swab samples from 411 children under the age of five who presented with symptoms of unexplained acute respiratory infection and were negative for bacteria, mycoplasma, and influenza viruses. Using viral metagenomic techniques, viral nucleic acids were extracted, enriched, and sequenced from the samples. Results indicated that Picornaviridae, Parvoviridae, Paramyxoviridae, Coronaviridae, and Anelloviridae were the five virus families with the highest relative content of sequence reads. And we detected 35 HBoV-positive and 12 HEV-positive samples out of 411 samples by the polymerase chain reaction (PCR). Partial or nearly complete genome sequences of viruses belonging to the families Picornaviridae, Parvoviridae, and Anelloviridae were characterized, and phylogenetic trees were constructed based on the nucleic acid or amino acid sequences of the predicted viral open reading frames (ORFs), as well as genotyping of the viruses. In addition, we observed recombination events in the Saffold virus and Coxsackievirus A9 by analyzing the genetic characteristics of the viruses revealed in this study. This study provides vital information for the prevention and treatment of acute respiratory infections in children younger than five years old.

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.

Serological Surveillance of the H1N1 and H3N2 Swine Influenza A Virus in Chinese Swine between 2016 and 2021

Background

Swine influenza A virus (IAV-S) is a common cause of respiratory disease in pigs and poses a major public health threat. However, little attention and funding have been given to such studies. The aim of this study was to assess the prevalence of the Eurasian avian-like H1N1 (EA H1N1), 2009 pandemic H1N1 (pdm/09 H1N1), and H3N2 subtype antibodies in unvaccinated swine populations through serological investigations. Such data are helpful in understanding the prevalence of the IAV-S.

Methods

A total of 40,343 serum samples from 17 regions in China were examined using hemagglutination inhibition (HI) tests against EA H1N1, pdm/09 H1N1, and H3N2 IAV-S from 2016 to 2021. The results were analyzed based on a reginal distribution, seasonal distribution, and in different breeding stages.

Results

A total of 19,682 serum samples out of the 40,343 were positive for IAV-S (48.79%). The positivity rates to the EA H1N1 subtype, pdm/09 H1N1 subtype, and H3N2 subtype were 24.75% (9,986/40,343), 7.94% (3,205/40,343), and 0.06% (24/40,343), respectively. The occurrences of coinfections from two or more subtypes were also detected. In general, the positivity rates of serum samples were related to the regional distribution and feeding stages.

Conclusions

The results of this study showed that the anti-EA H1N1 subtype and pdm/09 H1N1 subtype antibodies were readily detected in swine serum samples. The EA H1N1 subtype has become dominant in the pig population. The occurrences of coinfections from two or more subtypes afforded opportunities for their reassortment to produce new viruses. Our findings emphasized the need for continuous surveillance of influenza viruses.

Retrospective study of clinical characteristics and viral etiologies of patients with viral pneumonia in Beijing

Aims

The virus is common in patients with viral pneumonia. However, the viral etiology and clinical features of patients with viral pneumonia in China remain unclear. The main purpose of this study was to analyze the viral causes and epidemiology of patients with viral pneumonia in Beijing, which can significantly improve the pertinence and accuracy of clinical treatment of the disease.

Methods

Firstly, 1539 respiratory specimens of pneumonia (oropharyngeal swabs, nasopharyngeal swabs, saliva samples and bronchoalveolar lavage fluid) were collected from 19 hospitals in Beijing from September 2015 to August 2018. Then, TaqMan low-density microfluidic chip technology was used to detect viral pneumonia specimens in 1539 respiratory tract specimens of pneumonia and determine the types of viral bacteria in them. Lastly, the analysis of demographic, clinical and etiological data of patients with viral pneumonia was performed.

Results

The results showed that among the 1539 respiratory tract specimens with pneumonia, 760 were detected as viral pneumonia specimens, with a positive rate of 49.4%. Among which, 467 were infected with mono-viral and 293 were infected with multi-viral. Influenza A virus (Flu A), mycoplasma pneumoniae (MPn), Ebola virus (EBV) and herpes simplex virus type 1 (HSV-1) were the major viral components in the samples of these patients. Furthermore, these viral species were significantly associated with sample sources, onset season and certain clinical characteristics.

Discussion

Our findings may provide corresponding treatment strategies for viral pneumonia patients infected with specific viruses.

Epidemiology and Seasonality of Childhood Respiratory Syncytial Virus Infections in the Tropics

Infections caused by respiratory syncytial virus (RSV) are a major cause of morbidity and mortality in young children worldwide. Understanding seasonal patterns of region-specific RSV activity is important to guide resource allocation for existing and future treatment and prevention strategies. The decades of excellent RSV surveillance data that are available from the developed countries of the world are incredibly instructive in advancing public health initiatives in those regions. With few exceptions, these developed nations are positioned geographically across temperate regions of the world. RSV surveillance across tropical regions of the world has improved in recent years, but remains spotty, and where available, still lacks the necessary longitudinal data to determine the amount of seasonal variation expected over time. However, existing and emerging data collected across tropical regions of the world do indicate that patterns of infection are often quite different from those so well described in temperate areas. Here, we provide a brief summary regarding what is known about general patterns of RSV disease activity across tropical Asia, Africa and South America, then offer additional country-specific details using examples where multiple reports and/or more robust surveillance data have become available.

The matrix gene of pdm/09 H1N1 contributes to the pathogenicity and transmissibility of SIV in mammals

The H1N1 influenza virus of swine-origin was responsible for the H1N1 pandemic in 2009 (pdm/09 H1N1), where the virus was transmitted to humans and then spread between people, and its continued circulation has resulted in it becoming a seasonal human flu virus. Since 2016, the matrix (M) gene of pdm/09 H1N1 has been involved in the reassortment of swine influenza viruses (SIVs) in China and has gradually become a dominant genotype in pigs. However, whether M gene substitution will influence the fitness of emerging SIVs remains unclear. Here, we analyzed the biological characteristics of SIVs with the M gene from Eurasian avian-like (EA) SIV or pdm/09 H1N1 in mammals and found that SIVs containing the pdm/09-M gene exhibit stronger virulence in mice, more efficient respiratory droplet transmission between ferrets, and increased transcription of viral genes in A549 cells compared with those containing EA-M. We also determined the functional significance of the pdm/09-M gene in conferring an elevated release of progeny viruses comprised of largely filamentous virions rather than spherical virions. Our study suggests that pdm/09-M plays a crucial role in the genesis of emerging SIVs in terms of the potential prevalence in the population.

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.

Etiological analysis of virus, mycoplasma pneumoniae and chlamydia pneumoniae in hospitalized children with acute respiratory infections in Huzhou

BACKGROUND

Acute respiratory infections are a common disease in children with high mortality and morbidity. Multiple pathogens can cause acute respiratory infections. A 2-year survey of hospitalized children was conducted to understand the epidemic situation, seasonal spread of pathogens and the improvement of clinical diagnosis, treatment and prevention of disease in Huzhou, China.

METHODS

From September 2017 to August 2019, 3121 nasopharyngeal swabs from hospitalized children with acute respiratory infections were collected, and real-time PCR was used to detect various pathogens. Then, pathogen profiles, frequency and seasonality were analyzed.

RESULTS

Of the 3121 specimens, 14.45% (451/3121) were positive for at least one pathogen. Of the single-pathogen infections, RSV (45.61%, 182/399) was the most frequent pathogen, followed by PIVs (14.79%, 59/399), ADV (14.54%, 58/399), MP (10.78%, 43/399), and IAV (5.26%, 21/399). Of the 52 coinfections, RSV + PIVs viruses were predominantly identified and accounted for 40.38% (21/52) of cases. RSV was the most frequent pathogen in all four groups. The highest positive rate of the pathogens occurred in the winter (21.26%), followed by autumn (14.98%), the summer (14.11%) and the spring (12.25%).

CONCLUSION

Viruses are the main pathogens in hospitalized children with acute respiratory infections in Huzhou city, Zhejiang Province, China. Among the pathogens, RSV had the highest detection rate, and MP is also a common pathogen among children with acute respiratory infections. This study provided a better understanding of the distribution of pathogens in children of different ages and seasons, which is conducive to the development of more reasonable treatment strategies and prevention and control measures.

Detection and clinical characteristics analysis of respiratory viruses in hospitalized children with acute respiratory tract infections by a GeXP-based multiplex-PCR assay

Background

The information regarding viral epidemiology and clinical characteristics in hospitalized children with acute respiratory tract infection (ARTI) in central Fujian is limited. In this study, we aimed at analyzing the viral epidemiology and clinical characteristics of ARTI in hospitalized children admitted to The First Affiliated Hospital of Fujian Medical University.

Methods

Cohort of 386 hospitalized children (31 days to 15 years) diagnosed with ARTI admitted to the Department of Pediatrics from January 1, 2018, to December 31, 2018, was enrolled in this study. Nasopharyngeal swab or sputum samples on the day of hospitalization were tested for 11 viruses via a GeXP‐based multiplex‐PCR assay. The viral profiles and clinical characteristics were analyzed.

Results

The overall positive rate of the samples was 43.26% (167/386). Among the 167 positive samples, 134 (80.24%, 134/167) had a single virus and 33 (19.76%, 33/167) had multiple viruses. There was a significant difference in the frequency of single vs mixed infections among positive samples (80.24% vs 19.76%; χ² = 122.168, P = .000) as well as among the total examined samples (34.72% vs 8.55%; χ² = 77.945, P = .000). Human rhinovirus was the most prevalent virus (17.36%, 67/386), followed by influenza A (5.96%, 23/386) and human adenovirus (5.70%, 22/386). There was no significant difference in the etiological distribution of viral pathogens between males and females (χ² = 0.480, P = .489). Viral infections were more likely to occur in the winter‐spring months than in the summer‐autumn months (52.51% vs 33.53%, χ² = 13.830, P = .000).

Conclusions

The GeXP‐based multiplex PCR is an accurate and high‐throughput assay allows us to quickly detect multiple respiratory viruses simultaneously in pediatric patients. Our study provides information on the viral profiles and clinical characteristics in hospitalized children with ARTI, which would help better effective prevention strategies.

[Treatment of influenza and other acute respiratory viral infections in patients with diabetes mellitus]

PURPOSE OF THE STUDY

The study of the influenza and ARVI clinical performance, the development of patients with diabetes mellitus, evaluation of the effectiveness and safety application of antiviral therapy, carried out in the framework of routine clinical practice.

MATERIALS AND METHODS

126 patients aged from 22 to 83 years (27.8% of men) with ARVI or influenza that occurred with medical care during the first 5 days of the disease (60.3% in the first 48 hours) are included. All patients suffer from diabetes, for the treatment of which oral hypoglycemic agents or insulins were constantly taken. The patients were divided into two groups: the first group received standard symptomatic treatment of ARVI; antiviral drug Kagocel.

RESULTS AND CONCLUSION

Diabetes and other acute respiratory viral infections. There is an increase in the incidence of bacterial complications - 2.2 times, an increase in the frequency of systemic antibiotics - 2.3 times. The purpose of the drug prescription led to a more rapid regression of all the symptoms of influenza and ARVI, but the most striking positive dynamics was observed in the symptoms of general weakness and headache. The prescription of Kagocel was accompanied by a 58% reduction in the number of bacterial complications and a 53% reduction in the use of antibiotics, which led to a reduction in the number of cases of the disease and an improvement in initial diseases, with an frequency increase in 1.8 times. The most significant effect achieved with early treatment and early initiation of antiviral therapy (in the first 48 hours of the disease).