The role of influenza, RSV and other common respiratory viruses in severe acute respiratory infections and influenza-like illness in a population with a high HIV sero-prevalence, South Africa 2012–2015

• Detection rate attributable to illness reflects a more accurate description of the prevalence of viruses causing respiratory disease.
• Influenza, RSV and hMPV considered pathogens if detected with PCR patients with Influenza like illness or severe acute respiratory illness.
• Rhinovirus and adenovirus identified among controls suggesting that they may cause only a proportion of clinical disease.

BackgroundViruses detected in patients with acute respiratory infections may be the cause of illness or asymptomatic shedding.ObjectiveTo estimate the attributable fraction (AF) and the detection rate attributable to illness for each of the different respiratory virusesStudy designWe compared the prevalence of 10 common respiratory viruses (influenza A and B viruses, parainfluenza virus 1–3; respiratory syncytial virus (RSV); adenovirus, rhinovirus, human metapneumovirus (hMPV) and enterovirus) in both HIV positive and negative patients hospitalized with severe acute respiratory illness (SARI), outpatients with influenza-like illness (ILI), and control subjects who did not report any febrile, respiratory or gastrointestinal illness during 2012–2015 in South Africa.ResultsWe enrolled 1959 SARI, 3784 ILI and 1793 controls with a HIV sero-prevalence of 26%, 30% and 43%, respectively. Influenza virus (AF: 86.3%; 95%CI: 77.7–91.6%), hMPV (AF: 85.6%; 95%CI: 72.0–92.6%), and RSV (AF: 83.7%; 95%CI: 77.5–88.2%) infections were associated with severe disease., while rhinovirus (AF: 46.9%; 95%CI: 37.6–56.5%) and adenovirus (AF: 36.4%; 95%CI: 20.6–49.0%) were only moderately associated.ConclusionsInfluenza, RSV and hMPV can be considered pathogens if detected in ILI and SARI while rhinovirus and adenovirus were commonly identified in controls suggesting that they may cause only a proportion of clinical disease observed in positive patients. Nonetheless, they may be important contributors to disease.