Objective: Rhinovirus (RV) infection is the most common single cause of acute respiratory illness in children. The purpose of the study was to evaluate the prevalence of RV in adenoid tissue throughout the year.
Material and methods: Fifty-six samples of adenoid tissue removed either due to recurrent otitis media or adenoid hypertrophy were collected for in-situ hybridization (ISH) of RV. To confirm the specificity of the ISH probe, eight adenoid biopsies were investigated by reverse transcriptase-polymerase chain reaction (RT-PCR) as well.
Results: ISH was positive for RV RNA in 45% of the specimens. There was a statistically significant difference (P = 0.002) in the prevalence of RV positive adenoid biopsies from late fall to spring (65%) in comparison to late spring to early fall (20%). Children with middle ear effusion were more often ISH positive than those with dry ears, but the number of past ear infections, signs of chronic nasal obstruction or recent runny nose did not correlate to the finding in ISH. There was a good concordance between the results obtained by ISH and by RT-PCR.
Conclusion: Both epithelial and/or germinal cells of adenoid tissue are frequently loaded with RV during the cold months of the year, also known to have a high incidence of RV infections among population. Children with otitis media with effusion are more likely to harbor RV in adenoid tissue than those with dry ears. Further studies are, however, needed to show whether the effusion is due to RV or whether this association exists by coincidence.