Upsurge in hospitalization of pediatric patients with severe acute respiratory infections in Kolkata and surrounding districts caused by recombinant human respiratory adenovirus type B 7/3

Globally, different genotypes of human adenoviruses are associated with outbreaks of acute respiratory infection (ARI) though such evidence is lacking from India. In the present study, we report a sudden increase in the positivity of respiratory adenovirus among hospitalized children with ARI from Kolkata and the surrounding districts of West Bengal, India, from December 2022 to date. A sharp rise in the positivity rate of respiratory adenovirus was found which ranged from 22.1% in early December 2022 to 52.6% in mid-March 2023. The overall positivity was 40.4% during the period and children in the 2 to <5 years (51.0%) age group were mostly affected. Single infection with adenovirus was found in 72.4% of cases while co-infection with rhinovirus was the maximum (9.4%). Around 97.5% of positive cases required hospitalization. Cough, breathlessness, and wheeze were the most common clinical features among positive patients. Phylogenetic analysis of the hexon and fiber gene of all the sequenced strains revealed HAdV-B 7/3 recombination with more than 99% homology within themselves. This report of a respiratory adenovirus outbreak in West Bengal, India causing severe illness in the pediatric population underscores the need for regular monitoring of the circulating strains.

Automated summary

A sudden increase in respiratory adenovirus positivity among hospitalized children with acute respiratory infection in Kolkata and surrounding districts of West Bengal, India, is reported. The positivity rate ranged from 22.1% in December 2022 to 52.6% in March 2023, with an overall positivity of 40.4% during the period. Children aged 2 to <5 years were most affected, and single infection with adenovirus accounted for 72.4% of cases. Regular monitoring of circulating strains is warranted.