Molecular epidemiology of human adenoviruses in children with and without respiratory symptoms: Preliminary findings from a case-control study

Abstract

Background Human adenovirus (HAdV) is an important viral agent in children which can lead to severe acute respiratory infection (SARI). Reports on molecular epidemiology of HAdVs in Iran are limited. This case-control study is conducted to compare the HAdV infection rate and molecular epidemiology among two groups of children with and without respiratory symptoms in Tehran, Iran during 2018–2019. Methods Nested PCR was performed on 120 oropharyngeal swabs taken from children aged five and younger with SARI who were hospitalized as the case group, and 120 oropharyngeal swabs were collected from children of the same age without respiratory symptoms as the control group. For positive samples Sanger sequencing was done and a phylogenetic tree was drawn afterward. Results Out of 120 cases, 8 (6.6%) tested positive for eachHAdV types including 6 (75%) HAdV-B7, 1 (12.5%) HAdV-C2, and 1 (12.5%) HAdV-C6. Among the control group, out of 120 samples, 8 (6.6%) were positive comprising 5 (62.5%) HAdV-C5, 2 (25%) HAdV-F41, and 1 (12.5%) HAdV-C6. Conclusion The present study indicated a different viewpoint of HAdV molecular epidemiology in which the genotypes were compared in children with and without respiratory symptoms. HAdV prevalence was equally common in cases and controls but different genotypes were detected in these two groups. HAdV-B7 was the main type among children with SARI, dissimilar to children with no respiratory symptoms where HAdV-C5 was the predominant type. Detecting HAdV-F in oropharyngeal swabs was a rare finding, which requires further investigation.

Assessing respiratory viral exclusion and affinity interactions through co-infection incidence in a pediatric population during the 2022 resurgence of influenza and RSV

“…These authors therefore concluded that qualitative PCR testing for adenovirus DNA alone was not useful in the pediatric population as a diagnostic test. Zadheidar et al (2022) found similar rates of adenovirus positivity in both symptomatic children and healthy controls, but found different subtypes predominated in each Pediatric co-infection probability relative to expected based on overall infection rate. The probability of viral co-infection was calculated based on the overall incidence of each co-infection pair, and compared to the expected probability of each co-infection type based on the incidence of each virus category as would be expected from stochastic interactions (random chance).…”

“…population (Zadheidar et al, 2022). The increased rates of coinfection involving adenovirus seen here may therefore be partially attributable to asymptomatic colonization.…”

“…Zadheidar et al. (2022) found similar rates of adenovirus positivity in both symptomatic children and healthy controls, but found different subtypes predominated in each population ( Zadheidar et al., 2022 ). The increased rates of co-infection involving adenovirus seen here may therefore be partially attributable to asymptomatic colonization.…”

Phylogenetic characterization of rhinovirus and adenovirus in hospitalized children aged ≤ 18 years with severe acute respiratory infection in Iran

“…Using hemi-nested PCR assay ( 4 ) ( Table 1 ) the spanning region of partial hexon was selected for detection and genotyping of HAdV. To run the assay 5 μl of DNA extraction product, 12.5 μl Ampliqon 2× master mix, and 12.5 pmol of each primer in a total volume of 25 μl was used in the first round.…”

“…These viruses are commonly circulating in the general population which include human rhinovirus (HRV), human adenovirus (HAdV), influenza virus, respiratory syncytial virus (RSV), human metapneumovirus (hMPV), parainfluenza viruses, enterovirus, bocavirus, and coronaviruses. Of particular interest are HRV and HAdV, which can frequently result in acute respiratory tract infections (ARTI) in young children requiring hospitalizations ( 2 – 4 ). HRVs (family Picornaviridae , genus Enterovirus ) are nonenveloped viruses, with single-stranded RNA (ssRNA), which are classified into three species (A, B, C) ( 5 ).…”