Comparative analysis between genotypes of adenovirus isolates from hospitalized children with acute respiratory tract infections and clinical manifestations in Wuhan, China, from June 2022 to September 2023

Abstract

Acute respiratory tract infections (ARTIs) are among the leading causes of morbidity and mortality in children worldwide. Human adenovirus (HAdV) infections are estimated to account for at least 5% of pediatric ARTIs. The circulated genotypes of HAdV and the correlation between genotype and clinical manifestations in Wuhan, China, before and after the complete relaxation of nonpharmaceutical interventions against severe acute respiratory syndrome coronavirus 2, remain unknown. Here, 101 HAdV strains were isolated from throat swab samples collected from hospitalized children with ARTIs who tested positive for HAdV nucleic acid. Of these, sixty-six strains from 2022 to twenty-three strains from 2023 were successfully genotyped and subjected to phylogenetic analysis based on the hexon, penton base, and fiber genes. Six genotypes, B3, C1, C2, C5, C104, and C108 were identified. HAdV-B3 (84.85%) was the most prevalent type in 2022, while HAdV-C (86.96%), including C1, C2, C108, and C104, was the most prevalent in 2023. These strains were phylogenetically related to strains from Japan, China, and the United States in recent years. When comparing clinical characteristics, pediatric patients infected with B3, C1, C2, C5, C104, or C108 exhibited similar clinical manifestations, primarily fever and cough, but varying interleukin (IL)-10 levels. In conclusion, from June 2022 to September 2023, the circulated genotypes of HAdV in Wuhan included B3, C1, C2, C108, C5, and C104. The endemic pattern of HAdV in Wuhan, China, shifted from species B as the dominant type in 2022 to species C in 2023.

Keywords: Acute respiratory tract infection (ARTIs); Clinical characteristics; Genotypes; Human adenovirus (HAdV); Pneumonia; Viral isolates.

Fig. 1

Flowchart of sample selection. A total of 100 and 50 HAdV-positive pharyngeal swab samples were selected in 2022 and 2023, respectively. Forty-nine cases of unsuccessful isolation of HAdV and 12 cases of unsuccessful HAdV genotyping were excluded, resulting in the selection of 66 and 23 HAdV-positive samples in 2022 and 2023, respectively.

Fig. 2

Isolation and identification of clinical HAdV strains. A Flow chart of isolation and identification of clinical HAdV strains. This diagram was drawn by Figdraw. B The cytopathic effects of HAdV infection. Vero cells were infected with one clinical HAdV strain. At 24 ​h post-infection, both infected and uninfected cells were observed under an optical microscope. Scale bars: 50 ​μm. C The replication of HAdV strain. Vero cells were infected with the HAdV strain. At 24 ​h post-infection, intracellular viral replication was detected by real-time PCR, and the copy number was presented with the Ct value. Infected supernatants were collected and detected for viral titer. The result was presented with a tissue culture infective dose (TCID₅₀).

Fig. 3

Neighbor-joining phylogenetic trees based on HAdV fiber (F) gene. De novo sequences (marked red for 2022; marked blue for 2023) of viruses collected in mainland China are identified by the province name, collection year, and number of strain preservation. The other sequences are identified by their GenBank ID, country of collection, and collection year. “B-others” represent HAdV-B7, -B11, -B14, -B16, -B21, -B34, -B35, -B50, -B55, -B66, -B68, -B76, -B77, -B78, -B79 or -B106.

Fig. 4

Neighbor-joining phylogenetic trees based on HAdV hexon (H) gene. De novo sequences (marked red for 2022; marked blue for 2023) of viruses collected in mainland China are identified by the province name, collection year, and number of strain preservation. The other sequences are identified by their GenBank ID, country of collection, and collection year. “B-others” represent HAdV-B7, -B11, -B14, -B16, -B21, -B34, -B35, -B50, -B55, -B66, -B68, -B76, -B77, -B78, -B79 or -B106.

Fig. 5

Neighbor-joining phylogenetic trees based on HAdV penton base (P) genes. De novo sequences (marked red for 2022; marked blue for 2023) of viruses collected in mainland China are identified by the province name, collection year, and number of strain preservation. The other sequences are identified by their GenBank ID, country of collection, and collection year. “B-others” represent HAdV-B7, -B11, -B14, -B16, -B21, -B34, -B35, -B50, -B55, -B66, -B68, -B76, -B77, -B78, -B79 or -B106.

Fig. 6

Changes in the endemic pattern of HAdV types among HAdV-positive cases from 2022 to 2023, in Wuhan, China. A The composition of HAdV types. B Age composition of HAdV-positive children.

Fig. 7

Comparison of IL-10 levels of children with different genotypes of HAdV infection. The sera of children with different genotypes of HAdV infection were collected and the levels of IL-10 were detected by using Cytokine Multiplex Detection Kit (Flow Cytometry) (CellGene Biotechnology Co., Ltd., Hangzhou, China). In B3 group, n ​= ​44; In C1 group, n ​= ​4; In C2 group, n ​= ​9; In C5 group, n ​= ​0; In C108 group, n ​= ​7; In C104 group, n ​= ​1.