Clinical Characteristics of 204 Children With Human Adenovirus Type 7 Pneumonia Identified by Whole Genome Sequencing in Liuzhou, China

Molecular epidemiology and phylogenetic analyses of human adenovirus in pediatric patients with acute respiratory infections from Hangzhou during COVID-19 pandemic

Background

Acute Respiratory Infections (ARIs) are a major cause of morbidity and mortality worldwide. Human Adenovirus (HAdV), responsible for 5%-10% of children's ARIs, is one of the most prevalent pathogens. Our study aimed to analyze the epidemiology and phylogenesis of HAdV in pediatric patients with ARIs in Hangzhou during the COVID-19 pandemic.

Method

Between November 2020 and March 2021, we collected 1,442 nasopharyngeal swabs from children with ARIs at Children's Hospital, Zhejiang University School of Medicine. Epidemiological statistics, phylogenetic and amino acid (AA) mutation analysis were conducted.

Results

Our findings revealed that 386 (26.77%) samples tested positive for HAdV, with the highest rate in children aged 6-18 years and the lowest in children aged 0-1 year, indicating a different age preference of HAdV compared with pre-pandemic period. Outpatients had a significantly higher positive rate than inpatients. Moreover, patients with HAdV-coinfection exhibited more severe clinical symptoms than those with HAdV-single infection. Our phylogenetic analysis demonstrated that species HAdV-C (type 1, 2, 6) were the predominant circulating strains in Hangzhou during the COVID-19 pandemic. Further AA mutation analysis identified seventeen mutations of particular concern for biological characterization.

Conclusion

In conclusion, our study provides valuable epidemiological and molecular data that will aid in epidemiological surveillance, antiviral therapies and the development of specific vaccine types, leading to improve public health.

Molecular Typing of Mastadenoviruses in Simultaneously Collected Nasopharyngeal Swabs and Stool Samples from Children Hospitalized for Acute Bronchiolitis, Acute Gastroenteritis, and Febrile Seizures

This study determines and compares the frequency of human mastadenovirus (HAdV) presence in children with acute bronchiolitis (AB), acute gastroenteritis (AGE), and febrile seizures (FS), ascertains types of HAdVs associated with each individual syndrome and contrasts the findings with a control group of children. The presence of HAdVs was ascertained in simultaneously collected nasopharyngeal (NP) swabs and stool samples amplifying the hexon gene by RT-PCR; these were sequenced to determine the types of HAdVs. HAdVs were grouped into eight different genotypes. Of these, three (F40, F41, and A31) were found solely in stool samples, whereas the others (B3, C1, C2, C5, and C6) were found in both stool samples and NP swabs. The most common genotypes in NP swabs were C2 (found in children with AGE and FS) and C1 (only in children with FS), whereas in stool samples genotypes F41 (in children with AGE) and C2 (in children with AGE and FS) prevailed, and C2 was simultaneously present in both samples. HAdVs were more often detected in stool samples than in NP swabs in patients (with the highest estimated viral load in stool samples in children with AB and AGE) and healthy controls and were more common in NP swabs in children with AGE than in children with AB. In most patients, the characterized genotypes in NP swabs and stool samples were in concordance.

Pediatric Community-acquired Pneumonia: What is it, and How Do We Study It?

Pediatric community-acquired pneumonia in pre-school aged children is a common diagnosis, frequently treated with antibiotics although most often caused by viruses. An accurate assessment of treatment-related clinical outcomes is dependent on identifying the pathogen(s) and their susceptibility to treatment interventions.

Pneumonia in Children During the 2019 Outbreak in Xiamen, China

BACKGROUND

To understand the regional epidemiology and clinical characteristics of adenovirus pneumonia in hospitalized children during the 2019 outbreak of respiratory adenoviruses in China.

METHODS

We analyzed the epidemiologic trend of adenovirus in children hospitalized for acute lower respiratory tract infections in Xiamen in 2019. Adenovirus was identified using direct fluorescent antibody detection. During the peak seasons of adenovirus epidemic, 170 adenovirus-positive specimens were obtained for molecular typing, and the clinical data were collected.

RESULTS

Among the 9890 children hospitalized for acute lower respiratory tract infection, 609 (6.2%) were tested positive for adenovirus. The detection rate of adenovirus was significantly higher in boys than in grils (9.5% vs. 4.6%, P < 0.05). Adenovirus activity increased markedly between April and August with the prevalence of 7.3%-12.4%. During the outbreak season, type 7 accounted for 70.6%, followed by type 3 (28.8%) and type 4 (0.6%). Of the 155 cases of adenovirus pneumonia, the median age was 3.0 years (range: 4 month to 9 years), 153 (98.7%) had fever with a mean fever duration of 9.04 ± 5.52 days, 28 (16.5%) had wheezing, 93 (60%) showed segmental or lobar consolidation with atelectasis and 13 (8.4%) showed pleural effusion. Forty-six (29.6%) cases developed severe pneumonia, 7 (4.1%) required mechanical ventilation and 2 (1.2%) died. Younger age, longer duration of fever and higher fever spike were more frequently seen in severe cases (P < 0.05). Twenty-five (16.2%) had C-reactive protein ≥ 40 mg/L, and 91 (58.7%) had procalcitonin ≥ 0.25 mg/L.

CONCLUSIONS

Adenovirus types 7 and 3 caused the outbreak of adenovirus pneumonia in community children during late spring to summer in 2019 in Xiamen. The majority of adenovirus pneumonia resembles bacterial pneumonia. The incidence of severe pneumonia was high when type 7 predominantly prevailed. Adenovirus type 7 was more common in severe cases than in nonsevere cases.

Difference in clinical features and prognosis of severe adenoviral pneumonia in children with different ages

OBJECTIVE

This study aims to analyze the difference in clinical features and prognosis of severe adenovirus pneumonia (SAP) in children of different ages, and analyze the risk factors for poor prognosis in children with SAP.

METHODS

A retrospective observational study was performed to describe the clinical features and analyze the risk factors for death and post-infectious bronchiolitis obliterans (PIBO) in 303 children hospitalized with SAP from January 2015 through to January 2020. The participants were divided into 4 age groups: < 6 months (n = 25, 8.3%); 6-12 months (n = 98, 32.3%); 12-36 months (n = 118, 38.9%); and > 36 months (n = 62, 20.5%).

RESULTS

Fever rate, peak, and duration were the lowest in the < 6 months group, while no significant difference was found among other age groups. Serum levels of lactate dehydrogenase (LDH) and the load of adenovirus were the lowest in the < 6 months group, and the highest in the 6-12 months and 12-36 months groups, respectively. A total of 80.9% of patients recovered, 3.3% of patients died, and 15.8% of patients were diagnosed PIBO. The mortality rate showed no significance between age groups. The > 36 months group had the highest recovery rate and the lowest incidence of PIBO, while the 6-12 months group had the lowest recovery rate and the highest incidence of PIBO. Independent risk factors for PIBO among all participants from the 4 groups were invasive mechanical ventilation, administration of intravenous steroids, duration of fever, and male gender. Independent risk factors for death among all participants from the 4 groups were hypercapnia, low albumin levels, and invasive mechanical ventilation. Risk factor analysis of different ages was not possible due to the limited sample size.

CONCLUSIONS

The morbidity, clinical features, and prognosis of SAP are affected by children's ages. Pediatric patients with a longer duration of fever, hypercapnia, low serum albumin levels, invasive mechanical ventilation, and intravenous steroids use are more likely to develop a poor prognosis in SAP, especially if the patient is male. This article is protected by copyright. All rights reserved.

Lactate dehydrogenase and the severity of adenoviral pneumonia in children: A meta-analysis

BACKGROUND

Children with severe adenoviral pneumonia (ADVP) have poor prognosis and high risk of mortality. We performed a meta-analysis to evaluate the association between pretreatment lactate dehydrogenase (LDH) and severity, postinfectious bronchiolitis obliterans (PIBO), and mortality in children with ADVP.

METHODS

Relevant observational studies were identified by search of PubMed, Embase, Web of Science, Wanfang, and CNKI databases from inception to August 3, 2022. A random effect model was used to pool the results by incorporating the potential between-study heterogeneity.

RESULTS

Overall, 23 studies with 4,481 children with ADVP were included in this meta-analysis. Results of meta-analysis showed that children with severe ADVP had a significantly higher level of pretreatment LDH as compared to those with non-severe ADVP (standard mean difference [SMD]: 0.51, 95% confidence interval [CI]: 0.36 to 0.66, p < 0.001; I ² = 69%). Besides, pooled results also suggested that the pretreatment LDH was significantly higher in children who developed PIBO as compared to those who did not (SMD: 0.47, 95% CI: 0.09 to 0.84, p = 0.02, I ² = 80%). Finally, results of the meta-analysis also confirmed that a higher pretreatment LDH (>500 IU/L) was a risk factor of increased mortality during hospitalization (odds ratio: 3.10, 95% CI: 1.62 to 5.92, p < 0.001, I ² = 0%). Sensitivity analyses by excluding one dataset at a time showed consistent results.

CONCLUSION

High pretreatment LDH may be associated with disease severity, development of PIBO, and increased risk of mortality in children with ADVP.

Clinical features and epidemiological analysis of respiratory human adenovirus infection in hospitalized children: a cross-sectional study in Zhejiang

Background

HAdV is one of the common pathogens in hospitalized children with acute respiratory infections (ARIs). We aim to describe the clinical and laboratory features, epidemiological characteristics, and HAdV species and/or types of inpatients with HAdV respiratory infections.

Methods

Respiratory samples were gathered from inpatients diagnosed ARIs in Children’s Hospital, Zhejiang University School of Medicine, and were detected by using Direct Immunofluorescence Assay from 2018 to 2019. PCR amplification and sequencing of the hypervariable zone of hexon gene were used for genotyping. The clinical and laboratory features, and HAdV genotyping, and epidemiological characteristic analysis were retrospectively performed.

Results

Of 7072 samples collected, 488 were identified as HAdV-positive. The overall detection rate was 6.9%. The peaked detection rate was 14.1% in January 2019. HAdV-positive cases with ARIs mainly appeared in winter. The detection rate was highest among children between 6 months and 2 years (8.7%, 123/1408). Clinical diagnosis included pneumonia (70.3%, 343/488), bronchitis (7.0%, 34/488) and acute upper respiratory tract infection (22.7%, 111/488). The common clinical manifestations were fever (93.4%, 456/488), cough (94.7%, 462/488), wheezing (26.2%, 128/488), and shortness of breath (14.8%, 72/488). 213 (43.6%) cases had co-infection and 138 (28.3%) cases had extrapulmonary symptoms. 96(19.7%) cases had intrapulmonary and intrathoracic complications.78 (16.0%) had an underlying condition, most of which were congenital heart diseases (20.5%, 16/78). The proportions of hyperpyrexia, duration of fever > 10 days, severe pneumonia, and wheezing in the co-infection group were remarkably higher than those in HAdV single-infection group (all p < 0.05). The proportions of duration of hospitalization, duration of fever > 10 days, wheezing, shortness of breath, change in level of consciousness, serosal fluids, extrapulmonary symptoms, co-infections and underlying diseases were significantly higher in severe pneumonia group than those in the mild pneumonia group (all p < 0.05). Four HAdV species were successfully identified in 155 cases and presented by 8 genotypes. HAdV-B3 (56.1%, 87/155) and HAdV -B7 (31.0%, 48/155) were the most predominant detected types and occurred commonly in different severity groups (p = 0.000), while, HAdV-B55 was detected only in the severe group. HAdV-B7’s detection rate in the severe pneumonia group was significantly higher than the non-severe pneumonia group.

Conclusion

HAdV detection rate is related to age and season. Bronchopneumonia accounts for about 70% HAdV-positive inpatients. The common clinical manifestations include hyperpyrexia, cough, wheezing, and shortness of breath. HAdV-B3 and HAdV-B7 are the most common types in children diagnosed with respiration infections.

Human adenovirus infections in pediatric population - an update on clinico-pathologic correlation

Human adenoviruses can cause infections at any age but most commonly in pediatric population, especially in young children and infants. By the time of 10 years old, most children have had at least one episode of adenovirus infection. Adenoviruses can cause many symptoms similar to common cold, including rhinorrhea, fever, cough, and sore throat. Lower respiratory infections such as bronchitis, bronchiolitis, and pneumonia can be severe and even fatal. Other diseases such as conjunctivitis, gastroenteritis, cystitis, myocarditis, cardiomyopathy, and meningoencephalitis can also be associated with adenovirus infections. A variety of recent advancement of structural and molecular biology methods have revamped the taxonomy of adenoviruses and furthered our understanding of the diversity of related clinical diseases. Because of the wide spectrum and complexity of diseases associated with human adenovirus infections, the scope of this review is limited to basic virology and epidemiology of adenoviruses with a main focus on the clinico–pathologic correlation. Clinical manifestations and pathology of any infectious disease are always related; therefore, it is logical to review clinico–pathologic correlation within the specific disease entity caused by adenoviruses to better understand this common viral infection in pediatric population.