Fatigue in Medical Residents Leads to Reactivation of Herpes Virus Latency

Abstract

The main objective of this study was to detect fatigue-induced clinical symptoms of immune suppression in medical residents. Samples were collected from the subjects atrest, following the first night (low-stress), and the last night (high-stress) of night float. Computerized reaction tests, Epworth Sleepiness Scale, and Wellness Profile questionnaires were used to quantify fatigue level. DNA of human herpes viruses HSV-1, VZV, EBV, as well as cortisol and melatonin concentrations, were measured in saliva. Residents at thehigh-stressinterval reported being sleepier compared to therestinterval. EBV DNA level increased significantly at bothstressintervals, while VZV DNA level increased only atlow-stress. DNA levels of HSV-1 decreased atlow-stressbut increased athigh-stress. Combined assessment of the viral DNA showed significant effect of stress on herpes virus reactivation at bothstressintervals. Cortisol concentrations at bothstressintervals were significantly higher than those atrest.