Molecular typing of conjunctivitis-causing adenoviruses in Hanoi, Vietnam from 2017 to 2019 and complete genome analysis of the most prevalent type (HAdV-8)

Molecular subtypes of Adenovirus-associated acute respiratory infection outbreak in children in Northern Vietnam and risk factors of more severe cases

BACKGROUND

Under the pressure of Human Adenovirus (HAdV)-associated acute respiratory infection (ARI) outbreak in children in Northern Vietnam in the end of 2022, this study was initiated to identify the HAdV subtype(s) and examine the associated clinical features and risk factors of more severe cases.

METHODS

This study evaluated pediatric patients with ARI which had tested positive for HAdV between October and November 2022 using a multiplex real-time PCR panel. Nasopharyngeal aspirates or nasal swab samples were used for sequencing to identify HAdV subtypes. Clinical data were collected retrospectively.

RESULTS

Among 97 successfully sequenced samples, the predominant subtypes were HAdV-B3 (83%), HAdV-B7 (16%) and HAdV-C2 (1%). Lower respiratory manifestations were found in 25% of the patients of which 5% were diagnosed with severe pneumonia. There was no significant association between HAdV subtype and clinical features except higher white blood cell and neutrophil counts in those detected with HAdV-B3 (p<0.001). Co-detection of HAdV with ≥1 other respiratory viruses was found in 13/24(54%) of those with lower respiratory manifestations and 4/5(80%) of those with severe pneumonia (odds ratio (95% confidence interval) vs. those without = 10.74 (2.83, 48.17) and 19.44 (2.12, 492.73) respectively after adjusting for age, sex, birth delivery method, day of disease).

CONCLUSION

HAdV-B3 and HAdV-B7 were predominant in the outbreak. Co-detection of HAdV together with other respiratory viruses was a strong risk factor for lower respiratory tract illnesses and severe pneumonia. The findings advocate the advantages of multi-factor microbial panels for the diagnosis and prognosis of ARI in children.

Etiological Study of Acute Conjunctivitis Caused by Human Adenovirus in Shanxi Province, China, between 2016 and 2019

Human adenovirus (HAdV) is the primary cause of acute conjunctivitis. To improve our understanding of the etiology of adenoviral conjunctivitis, ocular samples were collected from 160 conjunctivitis cases in the Shanxi province of northern China between 2016 and 2019. Through preliminary identification, virus isolation, and type identification, a total of 63 HAdV isolates were obtained from the samples. Three species and seven types (HAdV-3, HAdV-4, HAdV-8, HAdV-37, HAdV-53, HAdV-64, and HAdV-85) were detected, with HAdV-64, HAdV-3, and HAdV-8 being the predominant types in 2016, 2018, and 2019, respectively. Further phylogenetic analysis indicated the relative genomic stability of seven HAdV-type strains, except for 4 HAdV-3 strains in 2018 with a novel amino acid insertion site (Pro) between P19 and S20 in the penton base gene. It is worth noting that the genomes of two Shanxi HAdV-85 strains from 2016 were almost identical to those of previously reported HAdV-85 strains that circulated in Japan in 2014 to 2018. China was the second country to sample and isolate HAdV-85, suggesting that HAdV-85 might be underreported as an ocular pathogen. Data obtained in this study provide valuable information on the prevalence of acute conjunctivitis caused by HAdV. IMPORTANCE HAdV types in cases of conjunctivitis in Shanxi province, China, in 2016 to 2019 showed evident diversity, with seven types (HAdV-3, HAdV-4, HAdV-8, HAdV-37, HAdV-53, HAdV-64, and HAdV-85) being identified, and relative genome stability of these viruses was observed. In addition, China was the second country to sample and isolate HAdV-85, which suggests that HAdV-85 might be underreported as an important pathogen associated with ocular infections. These results enhance the understanding of the etiology of adenoviral conjunctivitis and may aid in the development of prevention and control strategies for HAdV-related ocular infections in China.

The molecular epidemiology, genotyping, and clinical manifestation of prevalent adenovirus infection during the epidemic keratoconjunctivitis, South of Iran

PURPOSE

Adenoviral-mediated keratoconjunctivitis is among the emergency diseases of ophthalmology with long-term sequels. The role of adenovirus infection, ocular-related genotypes, and association with ocular symptoms need to be investigated for epidemiological as well as clinical purposes.

METHODS

The affected patients from two close keratoconjunctivitis epidemics were included in the study. The swab samples were taken from patients; the total DNA was extracted and then used as a template for in-house Real-time PCR. Besides, partial Hexon genes of 11 adenovirus positive samples were amplified and submitted to sanger sequencing. Moreover, they were finally evaluated by phylogenetic analysis.

RESULTS

Of 153 patients, 92 (60.1%) were males and 47 cases (30.7%) had a history of eye infection in the family or colleagues. Real-time PCR tests of 126 samples (82.4%) were positive for adenovirus, and all eleven cases that underwent sequencing analysis were determined to be group 8 (HAdV-D8). Adenovirus infection has a significant relationship with infection among family or colleagues (p = 0.048), membrane formation (p = 0.047), conjunctival bleeding (p = 0.046), tearing, and pain(p < 0.05).

CONCLUSIONS

The results indicated that Adenovirus is the major cause of keratoconjunctivitis, and HAdV-D8 was the most common genotype in the area. There were some clinical manifestations associated with Adenovirus infection of the conjunctiva.

Molecular analysis of human adenoviral keratoconjunctivitis cases: Results of a 2-year survey

Objective: This study aimed to determine the adenovirus genotypes and their epidemiological features between January 2018 and November 2019, in Istanbul, Turkey. Material and Methods: Conjunctival swab samples were obtained from patients who were clinically diagnosed with keratoconjunctivitis. Samples were screened with an Adeno Detector kit (Rapid Pathogen Screening, RPS Inc., South Williamsport, PA). Nucleic acid extraction and amplification were performed with the ADENOVIRUS ELITe MGB® kit in the ELITe In Genius instrument (Elitech Group, Torino, Italy). For subtyping of the strains, sequencing primers targeted the ‘Hypervariable Region 7’ (HVR-7) of the hexon gene were used. DNA sequence analysis (n:72) was performed with ABI PRISM® 3100 Genetic Analyzer (Applied Biosystems, USA), and subtyping was done by BLAST analysis. Results: The median viral load in the samples (n: 77) was 7 log10 copies/mL (IQR: 4.5-7.4 log10 copies/mL). The clinical finding score was found to be significantly higher in the high viral load group (Adenovirus DNA≥6 Log 10 copies/mL) than in the low viral load group (Adenovirus DNA

First Record of HAdV-D20 Among Keratoconjunctivitis Patients in Iraq

Background

Human Adenovirus species D (HAdV-D) was common human viral pathogen especially in eye infection, consists of several types of which HAdV-D8, -D19 and -D37 were common in eye infection. This study includes detection of HAdV-D types implicated in conjunctivitis based on L2 (Penton protein) gene similarity.

Methods

Conjunctival swabs were collected from Keratoconjunctivitis patients as eye infection related to adenovirus. Viral nucleic acids were extracted and specific primer pairs for HAdV-D L2 gene (encoding for penton base protein) was used to amplify the target gene and only positive samples were sent to sequencing.

Results

The results revealed that only 6 samples give positive results for L2 gene amplification and then sent for sequencing for L2 (penton protein) gene-based typing. The results show that 4 local isolates (S1, S2, S3, S6) were similar to HAdV-D8 and 2 local isolates (S4, S5) were similar to HAdV-D20. Also the results display that the HAdV-37, prominent HAdV-D type of human eye infection, may be variant of HAdV-D20 due to that six variation were seen in S4and S5 local isolates nucleotide sequence in relation to HAdV-D37: T>C at position 14364, A>C at position 14411, T>C at position 14427, C>A at position 14448, G>A at position 14540 and T>C at position 14617, leading to only 2 amino acid change in resulted penton protein: T (Threonine) instead of K (Lysine) at position 204 and N (Asparagine) instead of D (Aspartic acid) at position 247.

Conclusion

The current study concludes the possibility of implication of HAdV-D20 in eye infections especially conjunctivitis.