Long-Term Survival, Morbidity, Social Functioning and Risk of Disability in Patients with a Herpes Simplex Virus Type 1 or Type 2 Central Nervous System Infection, Denmark, 2000–2016

Ann-Brit E Hansen,1– 3 Hanne T Vestergaard,4 Ram B Dessau,5 Jacob Bodilsen,6 Nanna S Andersen,7 Lars H Omland,1 Claus B Christiansen,8 Svend Ellermann-Eriksen,9 Lene Nielsen,10 Thomas Benfield,2,3 Henrik T Sørensen,11 Christian Ø Andersen,12 Anne-Mette Lebech,1,3 Niels Obel1,3 1Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; 2Department of Infectious Diseases, Amager Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark; 3Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark; 4Department of Virus & Microbiological Special Diagnostics, Statens Serum Institute, Copenhagen, Denmark; 5Department of Clinical Microbiology, Slagelse Hospital, Slagelse, Denmark; 6Departments of Infectious Diseases and Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark; 7Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark; 8Department of Clinical Microbiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; 9Department of Clinical Microbiology, Aarhus University Hospital, Aarhus, Denmark; 10Department of Clinical Microbiology, Herlev and Gentofte Hospital, University of Copenhagen, Herlev, Denmark; 11Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 12Department of Clinical Microbiology, Amager Hvidovre University Hospital, University of Copenhagen, Hvidovre, DenmarkCorrespondence: Ann-Brit E HansenDepartment of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, Copenhagen Ø DK-2100, DenmarkTel +45 30299306Email ann-brit.eg.hansen.02@regionh.dkBackground: The long-term prognosis following herpes simplex virus (HSV) central nervous system (CNS) infection is still debated.Patients and Methods: We examined outcomes in all Danish residents who, during 2000– 2016, tested PCR positive for HSV-1 (n=208) or HSV-2 (n=283) in the cerebrospinal fluid, compared to comparison cohorts from the general population (n=2080 and n=2830).Results: One-year mortality was increased among HSV-1 patients (difference 19.3%; 95% CI: 13.6% to 25.0%) and HSV-2 patients (difference 5.3%; 95% CI: 2.5% to 8.1%), but thereafter mortality was not increased. After exclusion of persons diagnosed with cancer prior to study inclusion, one-year mortality difference for HSV-2 patients was 1.7% (− 0.1% to 3.5%). After five years, HSV-1 patients had lower employment (difference − 19.8%; 95% CI: − 34.7% to − 4.8%) and higher disability pension rates (difference 22.2%; 95% CI: 8.4% to 36.0%) than the comparison cohort, but similar number of inpatient days, outpatient visits, and sick leave. HSV-2 patients had employment and disability pension rates comparable to the comparison cohort, but more inpatient days (difference 1.5/year; 95% CI: − 0.2 to 3.2), outpatient visits (difference 1.3/year; 95% CI: 0.3 to 3.2), and sick leave days (difference 9.1/year; 95% CI: 7.9 to 10.4).Conclusion: HSV-1 and HSV-2 CNS infections differ substantially with respect to prognosis. HSV-1 CNS infection is followed by increased short-term mortality and long-term risk of disability. HSV-2 CNS infection has no substantial impact on mortality or working capability but is associated with increased morbidity.Keywords: herpes simplex virus encephalitis, herpes simplex virus meningitis, prognosis, outcome, cohort study