Laboratory epidemiology of respiratory viruses in a large children's hospital: A STROBE-compliant article

Ye, Sheng; Wang, Tianlin

Lower limit of 95% CI from lower respiratory tract and is seldom used for viral testing. In our study, sputum showed higher positive rate for the detection of respiratory virus than swab. For example, adenovirus was more likely to be detected in swab than that in sputum (11.6% vs 8.0%; P < .001). This is inconsistent with the results obtained in a study conducted in adult outpatient, which showed that respiratory viruses were detected more frequently in sputum than that in swab. [19] Another study also showed that while bacteria were more frequently detected in sputum, virus was more frequently detected in swabs. [20] However, there are also other studies showing consistent results with our study. Branche et al showed that the sputum samples were able to increase the diagnostic yield of nasopharyngeal swab, which might be to higher viral loads in sputum than that in swabs. [21] Similar finding that sputum samples can increase diagnostic yield were replicated in other studies. [22, 23] Collectively, current evidences are inconsistent with regard to the diagnostic yield of sputum versus swab and further well controlled studies are required to settle this debate. Seasonal variations of different types of viruses have also been reported in other studies. Saraya et al [24] showed that influenza viruses were more frequently detected in spring and winter, and RSV was more common in autumn. The variation pattern of influenza viruses was generally consistent. However, our study showed that RSV was more common in winter and spring, which was different from that reported in Saraya's study. Their study was conducted in adult patients with asthma, which might be responsible for the difference. In another study conducted from the year 2002 to 2014 involving 5102 samples, RSV was most frequently detected from December to March, influenza viruses from November to March, and HRV from December to June. [25] Yang et al's [11] study found 2-peak patterns across age groups, one in winter and the other in spring/summer. The study was conducted in subtropical area, which was consistent with our study.