Severe infectious mononucleosis in immunocompetent adults

Abstract Objectives To determine the risk factors for severe infectious mononucleosis (IM) occurrence in immunocompetent adults. Methods We performed a multicenter, retrospective case series including immunocompetent adults presenting with confirmed IM between 2001 and 2011. Severe presentations were compared with uncomplicated presentations using Stata ®  9 software. The significance level was set at 5%. Results In univariate analysis, age over 30 years ( n  = 13 or 41.9% vs. n  = 5 or 12.8%; P  = 0.006), prior use of non-steroidal anti-inflammatory drugs (NSAIDs) ( n  = 7 or 87.5% vs. n  = 1 or 12.5%; P  = 0.009), and smoking ( n  = 13 or 68.4% vs. n  = 6 or 31.6%; P  = 0.013) were associated with severe IM onset. In multivariate analysis, only age over 30 years (OR = 3.55; P  = 0.05) and prior use of NSAIDs (OR = 15; P  = 0.05) remained associated with severe IM onset, without reaching significance level ( P  = 0.05). Conclusion Our study confirmed that age over 30 years is a risk factor for severe IM onset. Prior use of NSAIDs also seems to be correlated with severe presentations. This new data needs to be confirmed in a prospective study.