Characteristics and Long-term Prognosis of Danish Patients With Varicella Zoster Virus Detected in Cerebrospinal Fluid Compared With the Background Population.

BACKGROUND: Risk factors for, and long-term outcomes following, detection of varicella zoster virus (VZV) DNA in the cerebrospinal fluid (CSF) are unknown. METHODS: We performed a nationwide population-based cohort study of all Danish residents who had VZV DNA detected in the CSF by polymerase chain reaction (PCR) between 1 January 1997 and 1 March 2016 (VZV cohort; n = 517) and an age- and sex- matched comparison cohort from the general Danish population (n = 9823). We examined potential risk factors and mortality, neurologic morbidity, psychiatric morbidity, redemptiom of prescriptions for nervous system medicine prescribed for the nervous system, and social outcomes. RESULTS: Prior hospital admission, redemption of immunosuppressive medicine, comorbidity, and immunosuppressive conditions were associated with detection of VZV DNA in the CSF. Mortality was increased in the VZV cohort, especially during the first year of observation and among patients with encephalitis. Patients in the VZV cohort had an increased risk of dementia and epilepsy. The redemption of antiepileptics and antidepressants was increased in the VZV cohort. CONCLUSIONS: Immunosuppression and comorbidity are associated with increased risk of detection of VZV DNA in the CSF and the condition is associated with increased mortality and neurological morbidity.

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.

BACKGROUND: 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.

An unusual enterovirus outbreak in Denmark: clinical characteristics and molecular epidemiology.

In 2000, a large enterovirus (EV) outbreak was seen in Denmark; the number of patients with a verified EV infection was 3-fold higher compared to previous y. Echovirus 30 (E30) was the dominant EV type and was detected in 31% of all 306 EV positive patients and in 61% of the 155 patients in whom typing was successful. The outbreak started in February and peaked in June, which is unusually early in a temperate climate and not registered before in Denmark. The age distribution of the patients also differed from previous y with a significantly higher proportion of older children and adults being affected. The patients had mainly symptoms consistent with aseptic meningitis. A phylogenetic analysis based upon a part of the VP1 structural gene of 21 E30 isolates showed that the Danish isolates belonged to the E30 genotype which has prevailed in Europe during the last few years. However, they constituted a separated cluster compared with 2 other outbreaks in other parts of Europe in 2000.