Impact of RNA degradation on influenza diagnosis in the surveillance system

Abstract

BackgroundThe continuous evolution of influenza viruses is monitored by the World Health Organization Global Influenza Surveillance and Response System. Sample quality is essential for surveillance quality. MethodsTo evaluate the RNA degradation of clinical samples, influenza-like illness samples were collected from four sentinel hospitals, and seasonal influenza was tested by real-time reverse transcription polymerase chain reaction and quantified by digital reverse transcription polymerase chain reaction at different time points. ResultsRNA degradation was observed in the majority of samples eight days after sample collection. A significant and faster rate of RNA content reduction was observed in low viral load samples (<10 copies/µl) than in high viral load samples (>10 copies/μl), stored at 2 to 8°C for up to eight days. RNase P (RNP) RNA, which is a key indicator to evaluate sample collection quality, was detected. Sample collection quality was uneven in different hospitals. ConclusionLow viral load samples increase the risk of false negatives due to RNA degradation to undetectable levels.