Acute Disease ; Adenovirus Infections, Human ; Child ; Humans ; Molecular Epidemiology ; Molecular Typing ; Respiratory Tract Infections

Human adenovirus (HAdV) is one of the most important pathogens in infants and young children with acute respiratory infections and other diseases. This article reviews the literature on HAdV, including its molecular biological characteristics, detection and typing, and pathogenic mechanism, the clinical features and epidemiological characteristics of HAdV-related diseases, and the prevention and control of HAdV infections. So far, 67 types of HAdV have been identified, including recombinant variants discovered in recent years. The major epidemic strains that cause acute respiratory infections are HAdV-3 and HAdV-7, both of which belong to the subgroup B. HAdV often leads to acute respiratory infections, but it also causes diseases of other systems. HAdV-related diseases have similar clinical manifestations as those caused by other respiratory viruses, but often accompanied by gastrointestinal symptoms. The pathogenic mechanism of HAdV remains unclear, especially for the new recombinant variants, due to few studies on their association with diseases. Because there are no prospective, large randomized controlled trials of HAdV infections, the treatment of HAdV infections is controversial. Vaccine is the most effective measure to reduce respiratory HAdV infections, but it is still not commercially available.
Adenovirus Infections, Human ; virology ; Adenoviruses, Human ; classification ; genetics ; isolation & purification ; physiology ; Animals ; Humans

Adenoviruses are double stranded DNA viruses that cause an array of diseases. More than 60 types of human adenovirus have been reported so far. The discovery and division of human adenovirus types 52-67 are based on the genomic sequencing and bioinformatic analysisy and different from the pre-existing 51 serotypes identified by traditional serological methods in composition and pathogenicity. The majority of new types of human adenovirus are homologous recombination within the same subgenus, and as a result, certain new serotypes acquire different pathogenicity. Recombination is a common evolutionary way for human adenovirus, however, the mechanism of recombination and potenital danger to human remain unknown. As new types of human adenovirus have been receiving increasing attention, in this review, the latest progress in new types of human adenovirus is summarized.
Adenovirus Infections, Human ; virology ; Adenoviruses, Human ; classification ; genetics ; isolation & purification ; physiology ; Humans ; Molecular Sequence Data ; Phylogeny

Adenovirus Infections, Human ; epidemiology ; virology ; Adenoviruses, Human ; genetics ; Humans ; Molecular Epidemiology

As a single-center retrospective study, we analyzed the results of rotavirus and human adenovirus antigens in stool samples with colloidal gold immunochromatography method in children with acute gastroenteritis under the age of five who were treated in our hospital from 2019 to 2022. After excluding nonconforming cases and duplicate cases, 2 896 cases were included, of which 559 cases were detected with at least one viral antigen. According to the test results, they were divided into RV positive group, HAdV positive group and RV & HAdV double positive group. The gender, age, seasonal distribution, clinical symptoms and related laboratory tests were compared and analyzed with χ² test, analysis of variance and nonparametric test. Among the single samples from 2 896 children, the positive rate of RV antigen was 6.21% (180/2 896), the positive rate of HAdV antigen was 10.91% (316/2 896), and the double positive rate of RV & HAdV was 2.18% (63/2 896). The positive rate of HAdV antigen in 2021 was 16.11%, a significant increase compared with 6.20% in 2020. RV infection has obvious seasonality, and spring and winter are the seasons with high incidence of infection (χ²=74.018, P<0.001), while HAdV infection has no obvious seasonality (χ²=2.110, P=0.550), showing sporadic infection throughout the year. The proportions of fever and vomiting symptoms in children with RV infection were significantly higher than those in the HAdV infection group (χ²=40.401, P<0.001; χ²=32.593, P<0.001), but the positive rate of white blood cells in the stool was significantly lower than that in the HAdV infection group (χ²=13.741,P<0.01). In summary, paying attention to the epidemiological changes of RV and HAdV is of great significance for clinical diagnosis and treatment and disease prevention and control.
Child ; Humans ; Infant ; Rotavirus ; Retrospective Studies ; Gastroenteritis/epidemiology* ; Hospitals ; Feces ; Adenoviruses, Human ; Adenovirus Infections, Human/epidemiology*

Adenoviridae ; isolation & purification ; Adenovirus Infections, Human ; diagnosis ; Female ; Humans ; Infant ; Male ; Pneumonia, Viral ; diagnosis

Adenovirus Infections, Human ; epidemiology ; Child ; China ; epidemiology ; Disease Outbreaks ; Female ; Humans ; Incidence ; Male ; Respiratory Tract Infections ; epidemiology ; virology

Adenovirus (ADV) is one of the most common causes of acute respiratory infections for infants and children. The objective of this study was to understand the prevalence of ADV in acute respiratory infections in infants and children in Beijing and the types of the circulating ADVs. Clinical specimens were collected from patients with acute respiratory infections in a consecutive period of 10 years from Jan 2003 to Dec 2012. ADVs were detected from the collected clinical specimens by tissue culture and/or immunofluorescence assay and typed by nested-PCR based on the sequence of hexon gene for ADV types 3 and 7. For those strains which could not be typed by the nest-PCR, the gene fragment was amplified by a universal primer pair for all ADV types from group A to F and the PCR products were sequenced directly and analyzed with sequence comparison. Out of 39214 clinical specimens collected, including 7198 throat swabs from outpatients and 32016 nasopharyngeal aspirates from hospitalized patients, 884 were ADV positive by tissue culture and/or immunofluorescence assay, the overall positive rate was 2.25% (884/39214). The positive rate of ADV from the hospitalized was 2.08% (665/32016), while from the outpatients was 3.04% (219/7198). The ADV positive rate for year 2010 was 3.69%, which was the highest among the 10 years. The types of the ADVs were tested for 848 out of the 884 patients by using the nest-PCR and sequence analysis. It was showed that AD3 was the most prevalent with the rate of 53.18% (451/848), followed by AD7 36.79% (312/848), AD2 3.78% (32/848), AD55 2.24% (19/848), AD1 2.0% (17/848), AD5 0.94% (8/848), AD14 0.47% (4/848), AD6 0.35% (3/848) and AD4 0.24% (2/848). AD3 was the most predominant in most of the years among these 10 years, except 2012, 2003 and 2007. AD7 was the most predominant in 2012, and AD3 and AD7 were co-circulated in 2003 and 2007. Among 26 ADV infected severe pneumonia cases with pulmonary failure, 23 (88.5%) were AD7 positive, while 12 ADV associated tonsillitis, 11 (91.7%) were AD 3. The ADV positive rates from age groups 0-3 years were higher than age groups older than 4 years. The ratio for ADV positive males to females was 1.9 to 1. Adenovirus is still an important pathogen of acute respiratory infection in infants and young children. Most of the ADV associated acute respiratory infections in children in Beijing from 2003 to 2012 were AD3 and AD7. Most of the severe lower respiratory infections were associated with AD7. AD55 generated by recombination of AD11 and AD14 emerged in 2006.
Adenovirus Infections, Human ; epidemiology ; virology ; Adenoviruses, Human ; classification ; genetics ; isolation & purification ; Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Infant ; Male ; Respiratory Tract Infections ; epidemiology ; virology

Objective: To investigate the epidemiological characteristics of human adenovirus (HADV) 2, 3 and 7 in hospitalized children with respiratory infection. Methods: A total of 25 686 children with respiratory infection hospitalized at Children's Hospital of Hebei Province from January 2018 to December 2020 were retrospectively included.Deep sputum or nasopharyngeal aspirates of those children were collected. Then thirteen common respiratory pathogens were detected by multiplex PCR. 510 HADV positive specimens were randomly selected via random number and classified for type 2, 3 and 7 using a multiplex real-time quantitative PCR. SPSS 21.0 software was used to perform all of the statistical analyses. Enumeration data were expressed by frequency and percentage. χ² test was used for comparison between groups. Results: The HADV-positive rate was 7.99% (2 052/25 686). Children at age 3-<6 years had the highest HADV-positive rate (11.44%). The HADV-positive rate in 2019 was highest (10.64%). Among the 510 HADV-positive specimens, the proportion of type 3 was the highest (31.16%), followed by type 7 (21.37%) and type 2 (11.18%). The rate of type 2 in 2019 was significantly lower than that in 2018 and 2020 (χ²=8.954 and 16.354; P=0.003 and <0.01), while the rate of type 3 was significantly higher than that in 2018 and 2020 (χ²=5.248 and 4.811; P=0.022 and 0.028). The rate of type 2, type 3 and type 7 were lowest in winter, spring and autumn, respectively. The rate of type 2 increased significantly in autumn and the rate of type 3 and type 7 increased significantly in winter.The co-detection rate of HADV with other respiratory pathogens was 43.33%(221/510). Among, the co-detection rate of type 3 was highest (47.32%), and the co-detection rate of type 2, 3 and 7 was significantly higher than the alone detection rate (χ²=20.438, P<0.01; χ²=42.105, P<0.01; χ²=27.573, P<0.01).The proportion of severe pneumonia in children with type 7 positive (15.89%) was higher than that in children with non-type 7 positive (8.23%) (χ²=5.260, P=0.022). Conclusion: HADV is one of the important pathogens of children with respiratory infection in Children's Hospital of Hebei Province. The susceptible population of HADV is preschool children aged 3 to 6 years. HADV often co-detects with other respiratory pathogens. Type 3 and 7 is likely to be the dominant genotypes in this region, and type 7 may be one of the risk factors of severe pneumonia in children.
Child, Preschool ; Child ; Humans ; Infant ; Adenoviruses, Human/genetics* ; Child, Hospitalized ; Retrospective Studies ; Adenovirus Infections, Human/epidemiology* ; Respiratory Tract Infections/epidemiology* ; Pneumonia ; Hospitals

Objective: To compare the clinical characteristics of different types of human adenovirus (HAdV) infection in hospitalized children with acute respiratory infection in Beijing, and to clarify the clinical necessity of adenovirus typing. Methods: In a cross-sectional study, 9 022 respiratory tract specimens collected from hospitalized children with acute respiratory infection from November 2017 to October 2019 in Affiliated Children's Hospital, Capital Institute of Pediatrics were screened for HAdV by direct immunofluorescence (DFA) and (or) nucleic acid detection. Then the Penton base, Hexon and Fiber gene of HAdV were amplified from HAdV positive specimens to confirm their HAdV types by phylogenetic tree construction. Clinical data such as laboratory results and imaging data were analyzed for children with predominate type HAdV infection using t, U, or χ² test. Results: There were 392 cases (4.34%) positive for HAdV among 9 022 specimens from hospitalized children with acute respiratory infection. Among those 205 cases who were successfully typed, 131 were male and 74 were female, age of 22.6 (6.7, 52.5) months,102 cases (49.76%) were positive for HAdV-3 and 86 cases (41.95%), HAdV-7, respectively, while 17 cases were confirmed as HAdV-1, 2, 4, 6, 14 or 21. In comparison of clinical characteristics between the predominate HAdV type 7 and 3 infection, significant differences were shown in proportions of children with wheezing (10 cases (11.63%) vs. 25 cases (24.51%)), white blood cell count >15 ×10⁹/L (4 cases (4.65%) vs.14 cases (13.73%)), white blood cell count <5×10⁹/L (26 cases (30.23%) vs.11 cases (10.78%)), procalcitonin level>0.5 mg/L (43 cases (50.00%) vs. 29 cases (28.43%)), multilobar infiltration (45 cases (52.33%) vs.38 cases (37.25%)), pleural effusion (23 cases (26.74%) vs. 10 cases (9.80%)), and severe adenovirus pneumonia (7 cases (8.14%) vs. 2 cases (1.96%)) with χ²=5.11, 4.44, 11.16, 9.19, 4.30, 9.25, 3.91 and P=0.024, 0.035, 0.001, 0.002, 0.038, 0.002, 0.048, respectively, and also in length of hospital stay (11 (8, 15) vs. 7 (5, 13) d, Z=3.73, P<0.001). Conclusions: HAdV-3 and 7 were the predominate types of HAdV infection in hospitalized children with acute respiratory tract infection in Beijing. Compared with HAdV-3 infection, HAdV-7 infection caused more obvious inflammatory reaction, more severe pulmonary symptoms, longer length of hospital stay, suggesting the clinical necessity of further typing of HAdVs.
Adenovirus Infections, Human/epidemiology* ; Adenoviruses, Human/genetics* ; Beijing/epidemiology* ; Child ; Child, Hospitalized ; Cross-Sectional Studies ; Female ; Humans ; Infant ; Male ; Phylogeny ; Respiratory Tract Infections/epidemiology*