Respiratory virus detection in the upper respiratory tract of asymptomatic, community-dwelling older people

Background The prevalence of virus positivity in the upper respiratory tract of asymptomatic community-dwelling older people remains elusive. Our objective was to investigate the prevalence of respiratory virus PCR positivity in asymptomatic community-dwelling older people using saliva samples and nasopharyngeal and oropharyngeal swabs. Methods We analyzed 504 community-dwelling adults aged >= 65 years who were ambulatory and enrolled in a cross-sectional study conducted from February to December 2018 in Nagasaki city, Japan. Fourteen respiratory viruses were identified in saliva, nasopharyngeal and oropharyngeal samples using multiplex PCR assays. Results The prevalences of PCR positivity for rhinovirus, influenza A, enterovirus and any respiratory virus were 12.9% (95% CI: 10.1-16.1%), 7.1% (95% CI: 5.1-9.8%), 6.9% (95% CI: 4.9-9.5%) and 25.2% (95% CI: 21.5-29.2%), respectively. Rhinovirus was detected in 21.5% of subjects, influenza A in 38.9% of subjects, enterovirus in 51.4% of subjects and any virus in 32.3% of subjects using only saliva sampling. Conclusions The prevalences of several respiratory viruses were higher than the percentages reported previously in pharyngeal samples from younger adults. Saliva sampling is a potentially useful method for respiratory virus detection in asymptomatic populations.

Automated summary

The prevalence of respiratory virus positivity in asymptomatic community-dwelling older people was investigated using saliva samples and swabs. Several respiratory viruses were detected, with higher prevalence rates compared to younger adults. Saliva sampling is a potentially useful method for respiratory virus detection in asymptomatic populations.