Evaluation of Lytic and Persistent Human Adenovirus Infections in Tonsil Tissue of Children With Tonsillar Hypertrophy: A Matched Case–Control Study

Abstract

Background

Tonsillar hypertrophy is a common condition in children, and human adenoviruses (HAdVs) may contribute to its development. However, the mechanisms underlying HAdVs' persistence in tonsils remain unclear. This study investigates the role of HAdVs in tonsillar hypertrophy.

Methods

In a case–control study, oropharyngeal swabs and tonsillar tissues were collected from 50 children with and without tonsillar hypertrophy. HAdV viral load, mRNA expression, and virus shedding were considered to differentiate lytic and persistent infections.

Results

HAdV genomes were detected in 32% of hypertrophic tissues, exclusively HAdV-C, with no presence in controls. Viral loads varied, peaking in children under 5 years old, ranging from 4 × ${10}^3$ to 1.9 × ${10}^6$ copies/g, with a median of 2.6 × ${10}^4$ copies/g. Predominantly, infections were persistent (81%), with a smaller number of lytic or reactive cases.

Conclusion

The study supports and extends previous findings regarding HAdV-C persistence in tonsillar tissues and its potential contribution to hypertrophy, with viral loads tending to decrease with age. These findings contribute to the growing body of evidence on HAdVs' role in tonsillar hypertrophy, reinforcing the importance of persistent infections in the tonsils.