Adenovirus infection in children hospitalized with pneumonia in Guangzhou, China

Risk factors of severe conditions in hospitalized children with adenovirus infection and chest CT features

BACKGROUND

Children infected with human adenovirus (HAdV) were at particularly high risk of developing severe disease, but the risk factors of severe conditions are poorly understood.

OBJECTIVES

To explore the risk factors for developing into severe conditions in pediatric patients with HAdV infection by analyzing baseline epidemiological data, clinical characteristics, and computed tomography (CT) imaging features.

METHODS

In this retrospective study, 267 children with HAdV infection were included between October 2016 and September 2021 at Tongji Hospital, Wuhan, China. A descriptive analysis was conducted on the epidemiological and clinical data, as well as patient outcomes. CT manifestations were semi-quantitatively scored based on the presence of consolidation, ground-glass opacities, and emphysema in each lung lobe.

RESULTS

Our analysis revealed that there was a statistically significant difference in the rate of abnormalities observed on chest CT imaging (P = 0.007) and the imaging characteristics of chest CTs (P = 0.002) when comparing severe and mild cases. We found that co-infection with two or more additional pathogens occurred more frequently in severe cases. Additionally, the proportion of lymphocytes in laboratory tests was significantly lower in patients with severe conditions. Furthermore, both the proportions and scores of consolidations were markedly higher in each lung lobe among the severe cases.

CONCLUSIONS

Our findings may assist in identifying children hospitalized with HAdV who are at increased risk for severe conditions, thereby facilitating more aggressive treatment and care strategies.

Clinical characteristics and changes in serum CXCL10 and CXCL16 levels in patients with severe mycoplasma pneumonia

To explore the clinical characteristics and changes in serum CXCL10 and CXCL16 in patients with severe mycoplasma pneumonia, and to analyze the risk factors of severe mycoplasma pneumonia. About 258 children with acute mycoplasma pneumoniae pneumonia (MPP) admitted to the respiratory department of a certain hospital from January 2020 to December 2022 were selected as the study subjects. According to the severity of MPP, patients are divided into 2 groups, namely the mild illness group (Q group) and the severe illness group (Z group). The number of cases in these 2 groups of children is 167 and 91, respectively. The serum CXCL10, CXCL16, and other indicators of 2 groups are tested. Compared to group Q, patients in group Z have a higher proportion of extrapulmonary complications, longer cough time, longer shortness of breath, and longer wheezing time (P < .05). The serum CXCL16 is higher and the proportion of pleural effusion is higher (P < .01). There are more cases of fever, longer fever duration, longer hospital stay, higher serum CXCL10, and higher D-dimer levels (P < .001). The area under the curve of the probability curve for predicting severe mycoplasma pneumonia is 0.975 (P < .05). Children with severe mycoplasma pneumonia have significantly longer fever duration and hospital stay than those with mild symptoms. The serum levels of CXCL10 and CXCL16 are significantly elevated.

Etiological characteristics of acute respiratory infections during the SARS-CoV-2 epidemic in Guizhou Province, China

OBJECTIVE

Acute respiratory infections are a major global public health concern. However, there are few epidemiological studies investigating pathogens associated with respiratory tract infections in Guizhou Province, China.

METHODS

We collected 17,850 blood samples from Guizhou Provincial People's Hospital between November 2018 and May 2023 to investigate the epidemiological characteristics of respiratory pathogens and their spread during the SARS-CoV-2 epidemic in Guizhou Province.

RESULTS

We identified influenza virus and Mycoplasma pneumoniae as the predominant pathogens involved in acute respiratory infections in the study area. Immunoglobulin M positivity for respiratory syncytial virus, influenza virus, and M. pneumoniae showed a strong correlation with the clinical diagnosis of pneumonia. Seasonal epidemic patterns were observed for influenza A and B viruses. Following the SARS-CoV-2 outbreak, there was a significant decrease in the positive rates for most respiratory pathogens, particularly influenza A and B, Legionella pneumophila, and respiratory syncytial virus.

CONCLUSION

This retrospective study contributes to the epidemiological evidence regarding respiratory pathogens in Guizhou Province, thereby enhancing the surveillance network for respiratory pathogens in China and providing valuable guidance for local hospitals.

Plasma Metabonomics of Human Adenovirus-infected Patients with Pneumonia and Upper Respiratory Tract Infection

OBJECTIVE

Human adenovirus (HAdV) infection is common and can develop to serious conditions with high mortality, yet the mechanism of HAdV infection remains unclear. In the present study, the serum metabolite profiles of HAdV-7-infected patients with pneumonia or upper respiratory tract infection (URTI) were explored.

METHODS

In total, 35 patients were enrolled in the study following an outbreak of HAdV-7 in the army, of whom 14 had pneumonia and 21 had URTI. Blood samples were collected at the acute stage and at the recovery stage and were analyzed by untargeted metabolomics.

RESULTS

Over 90% of the differential metabolites identified between the pneumonia patients and URTI patients were lipids and lipid-like molecules, including glycerophospholipids, fatty acyls, and sphingolipids. The metabolic pathways that were significantly enriched were primarily the lipid metabolism pathways, including sphingolipid metabolism, glycerophospholipid metabolism, and linoleic acid metabolism. The sphingolipid metabolism was identified as a significantly differential pathway between the pneumonia patients and URTI patients and between the acute and recovery stages for the pneumonia patients, but not between the acute and recovery stages for the URTI patients. Ceramide and lactosylceramide, involved in sphingolipid metabolism, were significantly higher in the pneumonia patients than in the URTI patients with good discrimination abilities [area under curve (AUC) 0.742 and 0.716, respectively; combination AUC 0.801].

CONCLUSION

Our results suggested that HAdV modulated lipid metabolism for both the patients with URTI and pneumonia, especially the sphingolipid metabolism involving ceramide and lactosylceramide, which might thus be a potential intervention target in the treatment of HAdV infection.

Clinical features and prediction of risk factors for severe adenovirus pneumonia in children

Background

Adenoviral infections are most likely to invade the respiratory tract, and the clinical manifestations of the infections are varied; in severe cases, they may cause systemic multi-system damages and so on. At present, early clinical differential diagnosis is difficult under the existing testing methods, so it is important to analyze its clinical characteristics and risk factors for early identification of critical status and early and rational treatment.

Methods

The clinical data of 202 children with adenovirus pneumonia admitted to Tianjin Children's Hospital from January 2019 to December 2021 were retrospectively analyzed. According to the evaluation criteria for severe pneumonia, they were divided into a severe group (77 cases) and a non-severe group (125 cases). The clinical characteristics, complications, and laboratory data of the 2 groups were collected for statistical analysis, and then significant factors were analyzed by receiver operating characteristic curve (ROC) and binary logistic regression.

Results

Among the 202 children with adenovirus pneumonia, there were 108 males and 94 females. The children ranged in age from 2 months to 13 years. The duration of fever, incidence of wheezing, neutrophil ratio (NEUT%), and serum ferritin (SF) levels were significantly higher in the severe group than in the non-severe group (χ2/Z/P=-9.173/<0.001, 5.469/0.019, 5.831/<0.001, -3.845/<0.001). The incidences of liver injury, electrolyte disturbance, and coagulation dysfunction in the severe group were significantly higher than those in the non-severe group (χ2/Z/P=0.001/0.001, 28.208/0.001, 32.079/0.001). Logistic regression combined with ROC curve analysis suggested that fever duration >4.50 days, with wheezing, NEUT% ≥47.60, and SF ≥139.60 ng/mL were risk factors for developing severe adenovirus pneumonia in children [odds ratio (OR) (95% CI): 1.394 (1.230-1.581), 3.673 (1.246-10.828), 1.034 (1.001-1.067), 1.004 (1.001-1.008)].

Conclusions

Studies have shown that the fever associated with severe adenovirus pneumonia has a long duration, and that severe clinical manifestations and multiple complications, fever duration >4.50 days, wheezing, NEUT% ≥47.60, and SF ≥139.60 ng/mL are risk factors for severe adenovirus pneumonia.

Molecular epidemiology of circulating human adenoviruses among acute respiratory infection patients seeking healthcare facilities in West Bengal, India

Human adenovirus (HAdV) causes acute respiratory infections leading to mortality in children. This study analyzes the circulating respiratory HAdV genotypes in West Bengal, India during 2018-2022 among symptomatic patients. The overall positivity rate was 6.8%, out of which 26.4% were co-infected with other respiratory viruses. Children aged 2 to 5 years were mostly infected. Phylogenetic analysis revealed that the recombinant HAdV-B type 7/3, which has remarkable outbreak potential, predominantly circulated in this region followed by the non-recombinant HAdV-B type 3/3. Moreover, the amino acid sequences encoded by both the hexon and fiber genes of these two circulating strains possessed a few mutations that mostly diverged from the prototype strain, although the divergence was less pronounced in case of the amino acids encoded by the fiber gene of HAdV-B type 3/3. Overall, the results underscore the need for continuous surveillance of respiratory HAdV types to combat future possible epidemics.

Genome and proteomic analysis of risk factors for fatal outcome in children with severe community-acquired pneumonia caused by human adenovirus 7

INTRODUCTION

Human adenovirus 7 (HAdV-7) is an important viral pathogen of severe pneumonia in children and a serious threat to health.

METHODS

A cohort of 45 pediatric patients diagnosed with HAdV-7-associated severe pneumonia and admitted to the Pediatric Intensive Care Unit at the Children's Hospital of Chongqing Medical University from May 2018 to January 2020 were included. Risk factors of death were analyzed by the Cox proportional risk mode with Clinical data, serum, and nasopharyngeal aspirate adenovirus load, Genome analysis, Olink proteomics, and cytokine profile between dead and surviving patients were also analyzed.

RESULTS

A total of 45 children with a median age of 12.0 months (interquartile range [IQR]: 6.5, 22.0) were included (female 14), including 14 (31.1%) who died. High serum viral load was an independent risk factor for mortality (hazard ratio [HR] = 2.16, 95% confidence interval [CI], 1.04-4.49, p = 0.039). BTB and CNC homology 1 (BACH1), interleukin-5 (IL-5), and IL-9 levels were significantly correlated with serum viral load (p = 0.0400, 0.0499, and 0.0290; r = 0.4663, 0.3339, and -0.3700, respectively), with significant differences between the dead and survival groups (p = 0.021, 0.001, and 0.021).

CONCLUSIONS

Severe cytokine storm-associated high serum viral load after HAdV-7 infection may be the main mechanism responsible for poor prognosis in children.

A recombinant virus-like particle vaccine against adenovirus-7 induces a potent humoral response

Adenoviruses (AdVs) cause infections in humans that range from mild to severe, and can cause outbreaks particularly in close contact settings. Several human AdV types have been identified, which can cause a wide array of clinical manifestations. AdV types 4 and 7 (AdV-4 and AdV-7), which are among the most commonly circulating types in the United States, are known to cause acute respiratory disease that can result in hospitalization and rarely, death. Currently, the only vaccines approved for use in humans are live virus vaccines against AdV-4 and AdV-7, though these vaccines are only authorized for use in U.S. military personnel. While they are efficacious, use of these live virus vaccines carries considerable risks of vaccine-associated viral shedding and recombination. Here, we present an alternative vaccination strategy against AdV-7 using the virus-like particle platform (AdVLP-7). We describe the production of stable recombinant AdVLP-7, and demonstrate that AdVLP-7 is structurally analogous to wild-type AdV-7 virions (WT AdV-7). Preclinical immunogenicity studies in mice show that AdVLP-7 elicits a potent humoral immune response, comparable to that observed in mice immunized with WT AdV-7. Specifically, AdVLP-7 induces high titers of antibodies against AdV-7-specific antigens that can effectively neutralize AdV-7.

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.

Seroprevalence of neutralizing antibodies to human mastadenovirus serotypes 3 and 7 in healthy children from guangdong province

Severe adenovirus pneumonia is becoming more common in children infected with human mastadenovirus (HAdV)-3 and HAdV-7 than in those infected with other types of adenoviruses. Recently, there has been a trend toward an increasing prevalence of pneumonia caused by HAdV-7, an important viral pathogen in Pediatric Intensive Care Unit infections. Children infected with HAdV-7 have more serious symptoms of acute respiratory infections and other complications than those infected with HAdV-3. No specific anti-adenovirus drugs or vaccines are available for treatment or prevention. Therefore, we investigated the seroprevalence and titer levels of neutralizing antibodies (NAbs) against HAdV-3 and HAdV-7 in healthy children in Guangdong Province. We found that the seropositivity rates and antibody titers for HAdV-3 NAb were higher than those for HAdV-7 NAb. In children between 6 and 12 months of age, the seropositivity rates and titers were significantly low against HAdV-3 and HAdV-7. The HAdV-7-positive rate was significantly higher in the HAdV-3-positive samples than in the HAdV-3-negative samples. The HAdV-7 NAbs carried by the 0-6-month age group were dominated by low titers. These results reveal a low level of herd immunity against HAdV-3 and HAdV-7 in children, clarifying the importance of monitoring these two highly virulent adenoviruses, developing prophylactic vaccines, and predicting potential outbreaks.

Genetic characterization of human adenoviruses in patients using metagenomic next-generation sequencing in Hubei, China, from 2018 to 2019

Objectives

This study aimed to characterize the genomic epidemiology of human adenoviruses (HAdVs) in Hubei, China, using metagenomic next-generation sequencing (mNGS).

Methods

In total, 25 HAdV-positive samples collected from 21 pediatric patients were sequenced and subjected to mNGS using the NextSeq 550 and GenoLab M sequencing platforms. The metagenomic data were assembled de novo for molecular typing, phylogenetic and recombination analyzes.

Results

We assembled 50 HAdV genomes, 88% (22/25) genomes from GenoLab M, and 84% (21/25) genomes from NextSeq 550 have perfect alignments to reference genomes with greater than 90%. The most fully assembled 25 genomes were categorized into 7 HAdV genotypes, the most abundant of which were HAdV-B3 (9/25) and HAdV-C2 (6/25). Phylogenetic analyzes revealed that the newly isolated HAdV-B3 strains diverged into separate clusters according to their genotypes. Vigilance is needed that HAdV-B3 isolates have begun to form new distinct clusters. High nucleotide identity was observed in the whole genome level within the same HAdV genotypes, while marked differences of three capsid genes across HAdV genotypes were noted. The high nucleotide diversity regions were concordant with the reported hypervariable regions. Further, three recombinant strains were identified: S64 and S71 originated from the parental strains HAdV-B14 and HAdV-B11, and S28 originated from HAdV-C1, HAdV-C5, and HAdV-CBJ113. GenoLab M and NextSeq 550 showed comparable performance with respect to data yield, duplication rate, human ratio, and assembly completeness.

Conclusion

The sequencing quality and assembly accuracy showed that mNGS assembled genomes can be used for subsequently HAdV genotyping and genomic characterization. The high nucleotide diversity of capsid genes and high frequency of recombination events has highlighted the necessity for HAdV epidemiological surveillance in China.

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.

A nomogram for predicting severe adenovirus pneumonia in children

Adenoviral pneumonia in children was an epidemic that greatly impacted children's health in China in 2019. Currently, no simple or systematic scale has been introduced for the early identification and diagnosis of adenoviral pneumonia. The early recognition scale of pediatric severe adenovirus pneumonia was established based on an analysis of the children's community-acquired pneumonia clinical cohort. This study analyzed the clinical data of 132 children with adenoviral pneumonia who were admitted to the Children's Hospital of Nanjing Medical University. The clinical parameters and imaging features were analyzed using univariate and multivariate logistic regression analyses. A nomogram was constructed to predict the risk of developing severe adenovirus pneumonia in children. There were statistically significant differences in age, respiratory rate, fever duration before admission, percentage of neutrophils and lymphocytes, CRP, ALT, and LDH between the two groups. Logistic regression analysis was conducted using the R language, and respiratory rate, percentage of neutrophils, percentage of lymphocytes, and LDH were used as scale indicators. Using the ROC curve, the sensitivity and specificity of the scale were 93.3% and 92.1%. This scale has good sensitivity and specificity through internal verification, which proves that screening for early recognition of severe adenovirus pneumonia can be realized by scales. This predictive scale helps determine whether a child will develop severe adenovirus pneumonia early in the disease course.

An outbreak of acute respiratory disease caused by HAdV-55 in Beijing, China, 2020

Human adenoviruses (HAdVs) can cause acute respiratory diseases (ARDs) worldwide, and HAdV-55 is a reemergent pathogen in recent years. In the study, we investigated an outbreak of ARD at a school due to HAdV-55 in Beijing, China, during the early outbreak of coronavirus disease 2019 (COVID-19). The epidemic prevention team was dispatched to the school to collect epidemiologic data and nasopharyngeal samples. Then, real-time reverse transcription polymerase chain reaction (PCR) and multiplex PCR assays were used to detect severe acute respiratory syndrome coronavirus 2 and other respiratory pathogens, respectively. One representative HAdV-55 isolate was selected and submitted for whole-genome sequencing using a MiSeq system and the whole-genome phylogenetic tree was conducted based on the maximum likelihood method. The outbreak lasted from January 27 to February 6, 2020, and 108 students developed fever, among whom 60 (55.56%) cases were diagnosed with HAdV-55 infection in the laboratory using real-time PCR and 56 cases were hospitalized. All the confirmed cases had a fever and 11 cases (18.33%) presented with a fever above 39°C. Other main clinical symptoms included sore throat (43.33%) and headache (43.33%). We obtained and assembled the full genome of one isolate, BJ-446, with 34 761 nucleotides in length. HAdV-55 isolate BJ-446 was 99.85% identical to strain QS-DLL, which was the first HAdV-55 strain in China isolated from an ARD outbreak in Shanxi in 2006. One and four amino acid mutations were observed in the hexon gene and the coding region of L2 pV 40.1 kDa protein, respectively. We identified the first HAdV-55 infection associated with the ARD outbreak in Beijing since the emergence of COVID-19. The study suggests that improved surveillance of HAdV is needed, although COVID-19 is still prevalent in the world.

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

Human adenoviruses (HAdVs) are prevalent worldwide and are a common cause of respiratory tract infection in people of all ages. However, little is known about HAdV infection among children with severe acute respiratory infection (SARI). The present study retrospectively analyzed the molecular typing and epidemiological characteristics of HAdV-positive samples from children with SARI from January 2017 to December 2021 in Huzhou. The results showed that 89 (8.27%) of 1078 SARI pediatric patients were positive for HAdVs. Children < 5 years of age accounted for 87.64% of the positive cases. The peak seasons for HAdV infection were the first quarter and the fourth quarter. In addition, HAdV-B and HAdV-C were circulating among pediatric patients with SARI, of which the B3 genotype (n = 30, 51.72%) was the most prevalent and was detected every year, indicating that B3 is the main epidemic strain in the Huzhou area, followed by C1 (n = 9, 15.52%), C2 (n = 7, 12.07%), and B7 (n = 5, 8.62%). These findings provide a benchmark for future epidemiology and prevention strategies for HAdVs.

Adenovirus Infection in Hospitalized Children with Acute Respiratory Infection in Jordan

BACKGROUND

The most common clinical manifestation of adenovirus (AdV) infection is acute respiratory illness (ARI). Specific AdV species associated with ARI hospitalizations are not well defined in the Middle East.

METHODS

A viral surveillance study was conducted among children <2 years hospitalized in Amman, Jordan, from March 2010 to March 2013. Nasal and throat respiratory specimens were obtained from enrolled children and tested for viruses using a real-time reverse-transcription quantitative polymerase chain reaction. AdV-positive specimens were typed by partial hexon gene sequencing. Demographic and clinical features were compared between AdV detected as single pathogen versus co-detected with other respiratory viruses, and between AdV-B and AdV-C species.

RESULTS

AdV was detected in 475/3168 (15%) children hospitalized with ARI; of these, 216 (45%) specimens were successfully typed with AdV-C as the most common species detected (140/216; 65%). Children with AdV-single detection (88/475; 19%) had a higher frequency of fever (71% vs. 56%; P=0.015), diarrhea (18% vs. 11%; p=0.048), and/or seizures/abnormal movements (14% vs. 5%; p=0.003). Children with AdV co-detected with other viruses more likely required oxygen support [adjusted odds ratio (aOR) 1.91 (95% CI: 1.08, 3.39), P = 0.027] than those with AdV-single detection. Children with AdV-C had higher odds of co-detections with other viruses compared with those with AdV-B [aOR 4.00 (95% CI: 1.91, 8.44), P < 0.001].

CONCLUSION

Clinical differences were identified between AdV-single and AdV co-detected with other viruses, and between AdV-B and AdV-C. Larger studies with AdV typing are needed to determine additional epidemiological and clinical differences between specific AdV species and types.

Human adenovirus (HAdV) infection in children with acute respiratory tract infections in Guangzhou, China, 2010-2021: a molecular epidemiology study

BACKGROUND

Human adenovirus (HAdV) infection can cause a variety of diseases. It is a major pathogen of pediatric acute respiratory tract infections (ARIs) and can be life-threatening in younger children. We described the epidemiology and subtypes shifting of HAdV among children with ARI in Guangzhou, China.

METHODS

We conducted a retrospective study of 161,079 children diagnosed with acute respiratory illness at the Guangzhou Women and Children's Medical Center between 2010 and 2021. HAdV specimens were detected by real-time PCR and the hexon gene was used for phylogenetic analysis.

RESULTS

Before the COVID-19 outbreak in Guangzhou, the annual frequency of adenovirus infection detected during this period ranged from 3.92% to 13.58%, with an epidemic peak every four to five years. HAdV demonstrated a clear seasonal distribution, with the lowest positivity in March and peaking during summer (July or August) every year. A significant increase in HAdV cases was recorded for 2018 and 2019, which coincided with a shift in the dominant HAdV subtype from HAdV-3 to HAdV-7. The latter was associated with a more severe disease compared to HAdV-3. The average mortality proportion for children infected with HAdV from 2016 to 2019 was 0.38% but increased to 20% in severe cases. After COVID-19 emerged, HAdV cases dropped to 2.68%, suggesting that non-pharmaceutical interventions probably reduced the transmission of HAdV in the community.

CONCLUSION

Our study provides the foundation for the understanding of the epidemiology of HAdV and its associated risks in children in Southern China.

Clinical and Immunological Characteristics of Patients With Adenovirus Infection at Different Altitude Areas in Tibet, China

Background

The severities of human adenovirus (HAdV) infection are diverse in different areas of Tibet, China, where a large altitude span emerges. Serious consequences may be caused by medical staff if the clinical stages and immunological conditions of patients in high-altitude areas are misjudged. However, the clinical symptoms, immunological characteristics, and environmental factors of HAdV infection patients at different altitude areas have not been well described.

Methods

In this retrospective, multicenter cohort study, we analyzed the data of patients who were confirmed HAdV infection by PCR tests in the General Hospital of Tibet Military Command or CDC (the Center for Disease Control and Prevention) of Tibet Military Command from January 1, 2019, to December 31, 2020. Demographic, clinical, laboratory, radiological, and epidemiological data were collected from medical records system and compared among different altitude areas. The inflammatory cytokines as well as the subsets of monocytes and regulatory T cells of patients were also obtained and analyzed in this study.

Results

Six hundred eighty-six patients had been identified by laboratory-confirmed HAdV infection, including the low-altitude group (n = 62), medium-altitude group (n = 206), high-altitude group (n = 230), and ultra-high-altitude group (n = 188). Referring to the environmental factors regression analysis, altitude and relative humidity were tightly associated with the number of infected patients (P < 0.01). A higher incidence rate of general pneumonia (45.7%) or severe pneumonia (8.0%) occurred in the ultra-high-altitude group (P < 0.05). The incubation period, serial interval, course of the disease, and PCR-positive duration were prolonged to various extents compared with the low-altitude group (P < 0.05). Different from those in low-altitude areas, the levels of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, G-CSF, GM-CSF, IFN-γ, IP-10, MCP-1, TNF-α, TNF-β, and VEGF in the plasma of the ultra-high-altitude group were increased (P < 0.05), while the proportion of non-classical monocytes and regulatory T cells was decreased (P < 0.05).

Conclusions

The findings of this research indicated that patients with HAdV infection in high-altitude areas had severe clinical symptoms and a prolonged course of disease. During clinical works, much more attention should be paid to observe the changes in their immunological conditions. Quarantine of patients in high-altitude areas should be appropriately extended to block virus shedding.

Development of Rapid and Visual Nucleic Acid Detection Methods towards Four Serotypes of Human Adenovirus Species B Based on RPA-LF Test

Objectives

Human adenoviruses (HAdV) are classified as 7 HAdV species, and some serotypes in species B like HAdV 3, HAdV 7, HAdV 21, and HAdV 55 caused severe symptoms, even fatalities. Patients may be misdiagnosed and inadequately treated without reliable and practical methods for HAdV serotyping. Developing rapid, sensitive, and specific diagnostic methods for HAdV is critical.

Methods

Detection methods were established based on a recombinase polymerase amplification (RPA) assay and lateral flow (LF) test. Specific target sequence was screened, targeting which, primers and probes were designed, synthesized, and screened for establishing assay with high amplification efficiency. Primer or probe concentrations and amplification time were optimized. Detection limit, sensitivity, and specificity were evaluated. Results and Conclusions. Simple, sensitive, and specific RPA-LF methods for detection of four serotypes of HAdV together or separately were established, which had detection limits of 10 to 280 copies/reaction comparable to real-time PCR without recognizing other pathogens. The sensitivity and specificity were >92% and >98%, respectively, evaluated by limited clinical samples. The detection can be completed in 25 min without requirement of any instrument except a constant temperature equipment, showing superior detection performance and promising for a wide use in the field and resource-limited area.

Tree Shrew as an Emerging Small Animal Model for Human Viral Infection: A Recent Overview

Viral infection is a global public health threat causing millions of deaths. A suitable small animal model is essential for viral pathogenesis and host response studies that could be used in antiviral and vaccine development. The tree shrew (Tupaia belangeri or Tupaia belangeri chinenesis), a squirrel-like non-primate small mammal in the Tupaiidae family, has been reported to be susceptible to important human viral pathogens, including hepatitis viruses (e.g., HBV, HCV), respiratory viruses (influenza viruses, SARS-CoV-2, human adenovirus B), arboviruses (Zika virus and dengue virus), and other viruses (e.g., herpes simplex virus, etc.). The pathogenesis of these viruses is not fully understood due to the lack of an economically feasible suitable small animal model mimicking natural infection of human diseases. The tree shrew model significantly contributes towards a better understanding of the infection and pathogenesis of these important human pathogens, highlighting its potential to be used as a viable viral infection model of human viruses. Therefore, in this review, we summarize updates regarding human viral infection in the tree shrew model, which highlights the potential of the tree shrew to be utilized for human viral infection and pathogenesis studies.

Molecular typing of human adenoviruses among hospitalized patients with respiratory tract infections in a tertiary Hospital in Guangzhou, China between 2017 and 2019

Background

Human Adenoviruses (HAdVs) cause a wide array of illnesses in all age groups. They particularly cause frequent morbidity among children. In China, human adenovirus types 3, 4, 7, 11, 14, 21, and 55 have caused at least seven outbreaks since 2000. However, limited studies are available regarding the epidemiological patterns and diversity of HAdVs types among hospitalized patients with respiratory tract infections (RTIs).

Methods

To understand the epidemiology and subtype distribution of HAdV infections associated with RTIs in China, nasal swab (NS) clinical samples were collected from 4129 patients in a Guangzhou hospital between August 2017 and October 2019. PCR, sequencing, and phylogenetic analysis were performed on these specimens to identify HAdV subtypes.

Results

HAdV was successfully sequenced in 99 (2.4%) of the 4129 NS specimens, with the highest HAdV prevalence (6.3%) found in children between the ages of 5 and 10 years. Among HAdV-positive specimens, the most prevalent genotypes identified were HAdV-B3 (55.6%) and HAdV-B7 (25.3%). The most common symptoms in the HAdV-infected patients were fever (100%), cough (80.8%), and rhinorrhea (71.8%). HAdV infections were detected throughout the year with a relatively higher prevalence in summer.

Conclusion

All ages suffer adenovirus infections, but young children are at the greatest risk. This study data demonstrates that at least three species of HAdVs (species B, C, and E) are circulating in Guangzhou City, China. As antiviral therapies and type-specific vaccines become available, such epidemiological data will be useful in guiding therapy and public health interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06412-0.

The Epidemiology, Molecular, and Clinical of Human Adenoviruses in Children Hospitalized With Acute Respiratory Infections

Introduction

Human adenovirus (HAdV) is a common pathogen in children with acute respiratory infections (ARIs). The aim was to describe the epidemiology, molecular, and clinical characteristics of HAdV among children hospitalized with ARIs in Wenzhou in southeastern China.

Methodology

From January 2018 to December 2019, nasopharyngeal swab or sputum specimens were prospectively collected from hospitalized children with ARIs. HAdV was detected using direct immunofluorescence. We used a multiplex PCR assay combined with capillary electrophoresis targeting the hexon gene’s hypervariable region to identify HAdV types 1, 2, 3, 4, 5, 7, 14, 21, 37, 40, 41, and 55. We analyzed the epidemiological, molecular, and clinical data according to the HAdV type.

Results

HAdVs were detected in 1,059 (3.5%) of the total of 30,543 children tested. A total of 947 cases with monotype HAdV identified by the PCR assay were included in the analysis. HAdV-3 (415/947, 43.8%), HAdV-7 (318/947, 33.6%), HAdV-2 (108/947, 11.4%), and HAdV-1 (70/947, 7.4%) were the predominant types. Of the 550 (58.1%) cases detected from December 2018 to August 2019, HAdV-3, and HAdV-7 were the main types. The main diagnoses included 358 cases of pneumonia, 232 cases of tonsillitis, 198 cases of bronchitis, and 159 cases of upper respiratory tract infection (URTI). Among children with pneumonia the main types were HAdV-7 (51.1%), HAdV-3 (36.9%), and HAdV-1 (2.2%). Among children with bronchitis, the main types were HAdV-3 (48.0%), HAdV-7 (28.3%), and HAdV-2 (10.6%). Among children with URTIs, the main types were HAdV-3 (49.7%), HAdV-7 (22.6%), and HAdV-2 (13.2%). Among children with tonsillitis, the main types were HAdV-3 (47.4%), HAdV-2 (22.4%), and HAdV-7 (18.5%). In total, 101 (55.2%) patients required supplemental oxygen, 15 (8.2%) required critical care, and 1 child (0.5%) with HAdV-7 pneumonia died.

Conclusion

HAdV-3 -7, -2, and -1 were the predominant types identified in hospitalized children with ARIs in Wenzhou. From December 2018 to August 2019, there were outbreaks of HAdV-3 and -7. There were significant differences in HAdV types among children with pneumonia, tonsillitis, bronchitis, and URTI. HAdV-7 can cause more severe pneumonia in children than HAdV-3.

Perfil clínico-epidemiológico de crianças hospitalizadas: um recorte do período pandêmico e não pandêmico

RESUMO Objetivo Analisar o perfil clínico-epidemiológico de crianças e adolescentes hospitalizadas na clínica médica de um hospital pediátrico, referente aos períodos não pandêmico e pandêmico por COVID-19. Método Trata-se de estudo comparativo de natureza quantitativa, com delineamento transversal. A coleta de dados foi realizada em 219 prontuários do Serviço de Arquivo Médico e Estatística de um complexo pediátrico, no município de João Pessoa-PB. Quanto à análise dos dados, utilizou-se a estatística descritiva e testes estatísticos para comparar os grupos. Resultados O perfil das crianças e dos adolescentes hospitalizados teve predominância do sexo masculino, e de lactentes para o período não pandêmico e pandêmico, igualmente. A mãe foi a principal responsável e acompanhante da criança. As variáveis, natureza do benefício social, diagnóstico segundo especialidade médica e tempo de internação apresentaram diferenças estatísticas significativas entre os períodos não pandêmico e pandêmico por COVID-19. Conclusão Os dados encontrados apontam que não ocorreram mudanças expressivas no perfil sociodemográfico de crianças internadas. A pandemia por COVID-19 resultou em maior mudança no perfil clínico das internações. Implicações para a prática: Conhecer o perfil das crianças e adolescentes em processo de hospitalização, em um período pandêmico por COVID-19, auxiliará na elaboração de fluxos assistenciais e estratégias que atendam às reais demandas com propriedade.

Adenovirus infection in children hospitalized with pneumonia in Guangzhou, China

Background

HAdV infection can cause a variety of diseases. Although infections with HAdVs often are mild, life‐threatening respiratory disease can occur. Pneumonia is one of the more serious types of HAdV‐induced respiratory disease in children. In this study, we determined the prevalence and genotype of HAdVs among children hospitalized with pneumonia in Guangzhou, China.

Methods

Nasopharyngeal swabs (NPSs) were collected from children hospitalized with pneumonia in Guangzhou, China, from January 2013 to June 2019. HAdVs were detected by real‐time polymerase chain reaction assay, and hexon, fiber, and penton gene were amplified and used for phylogenetic analysis. Epidemiological data were analyzed using SPSS16.0 software.

Results and Conclusions

A total of 1778 children hospitalized with pneumonia were enrolled. The overall HAdV detection rate was 3.26%. And the yearly detection rate varied from around 2.5% in 2013‐2017 to around 6% in 2018‐2019. Children >5 years had the highest HAdV infection rate. 92.86% of HAdV sequences obtained in this study were belonged to species B, and no recombination was observed. HAdV‐B7 and HAdV‐B3 were the common types detected in the study period, with the predominant HAdV genotype shifted from HAdV‐B3 in 2015‐2016 to HAdV‐B7 in 2017‐2018. The discrepancies in HAdV detection rates in different study period and changes of HAdV predominant types over time highlighted the importance of continued surveillance.