The longitudinal health economic impact of viral encephalitis in the United States

The clinical epidemiology, management, and outcomes of patients diagnosed with encephalitis in North Carolina, 2015-2020

IMPORTANCE

Despite the relatively high mortality and the difficulty in diagnosis, nearly one-third of patients hospitalized with a documented diagnosis of encephalitis did not undergo a lumbar puncture (LP). When an LP was performed, pathogen-specific testing was greatly underutilized. Infectious etiologies were most common, but over 40% of cases were idiopathic at discharge. These findings suggest that there is a substantial opportunity to improve the quality of care through more accurate and timely diagnosis.

The Worldwide Prevalence of Herpes Simplex Virus Encephalitis and Meningitis: A Systematic Review and Meta-Analysis

Given the relatively high frequency of central nervous system infections and considerable mor- tality and morbidity reported to be caused by herpes simplex viruses among the other viral agents, having a clear knowledge about their epidemiological profile seems necessary. This systematic review and meta-analysis aimed to determine the relative frequency and preva- lence of herpes simplex encephalitis and meningitis in patients tested for viral etiologies. A comprehensive systematic review was performed in PubMed, Scopus, and Web of Science databases, searching for studies on the prevalence and relative frequency of herpes sim- plex virus 1 and herpes simplex virus 2 encephalitis and meningitis. Seventy-one studies were included. Overall, the prevalence of herpes simplex virus encephalitis among patients tested was 8% (95% confidence interval, 6%-11%; I2 = 98%) and the prevalence of herpes simplex virus meningitis among aseptic patients tested was 4% (95% confidence interval, 3%-7%; I2 = 95%), and a significant difference was observed by region. The results of our subgroup analysis for herpes simplex virus encephalitis revealed a prevalence of 8% for pediatric patients and ado- lescents and 12% for adults. The results for herpes simplex virus meningitis showed a prevalence of 4% for pediatric patients and adolescents and 9% for adults. We observed significant differ- ences in the frequency of herpes simplex virus 1 and herpes simplex virus 2 detection rates by region. Having high rates of missed cases due to inadequate, highly sensitive paraclinical tests performed on patients with suspected viral central nervous system infection is one of the pos- sible factors. More studies are needed to detect the possible flaws in the process of diagnosis in different regions.

Evolving etiologies, comorbidities, survival, and costs of care in adult encephalitis

Encephalitis is a central nervous system disorder, often caused by infectious agents or aberrant immune responses. We investigated causes, comorbidities, costs, and outcomes of encephalitis in a population-based cohort. ICD-10 codes corresponding to encephalitis were used to identify health services records for all adults from 2004 to 2019. Data were cross-validated for identified diagnoses based on laboratory confirmation using univariate and multivariate statistical analyses. We identified persons with a diagnosis of encephalitis and abnormal cerebrospinal fluid (CSF) results (n = 581) in whom viral genome was detected (n = 315) in a population of 3.2 million adults from 2004 to 2019. Viral genome-positive CSF samples included HSV-1 (n = 133), VZV (n = 116), HSV-2 (n = 34), enterovirus (n = 4), EBV (n = 5), and CMV (n = 3) with the remaining viruses included JCV (n = 12) and HHV-6 (n = 1). The mean Charlson Comorbidity Index (2.0) and mortality rate (37.6%) were significantly higher in the CSF viral genome-negative encephalitis group although the mean costs of care were significantly higher for the CSF viral genome-positive group. Cumulative incidence rates showed increased CSF VZV detection in persons with encephalitis, which predominated in persons over 65 years with a higher mean Charlson index. We detected HSV-2 and VZV more frequently in CSF from encephalitis cases with greater material-social deprivation. The mean costs of care were significantly greater for HSV-1 encephalitis group. Encephalitis remains an important cause of neurological disability and death with a viral etiology in 54.2% of affected adults accompanied by substantial costs of care and mortality. Virus-associated encephalitis is evolving with increased VZV detection, especially in older persons.

Global magnitude of encephalitis burden and its evolving pattern over the past 30 years

OBJECTIVE

We aimed to estimate the spatiotemporal patterns of the encephalitis burden along with its attributable risk factors at the national, regional, and global levels, which may be helpful in guiding targeted prevention and treatment programs.

METHODS

Based on available data sources, the incidence, mortality, and disability-adjusted life years (DALYs) of encephalitis in 204 countries and regions from 1990 to 2019 were reconstructed by the Global Burden of Disease Study 2019 using the Cause of Death Ensemble model, spatiotemporal Gaussian process regression, and DisMod-MR 2.1. We conducted a systematic analysis on the epidemiological characteristics of encephalitis in detail by gender, region, and age over the past three decades.

RESULTS

Globally, 1,444,720 incident cases, 89,900 deaths, and 4.80 million DALYs related to encephalitis were estimated in 2019. The age-standardized incidence rate and age-standardized mortality rate (ASMR) decreased from 23.17 and 2.18 to 19.33 and 1.19 per 100,000 person-years over the past 30 years, respectively. However, beginning in 2011-2013, the burden of encephalitis has shown an inflection point, with a further decline of the ASRs ceasing. Lower socio-demographic index (SDI) regions in South Asia, Western and Eastern Sub-Saharan Africa had the highest burden of encephalitis in 2019. During the past three decades, most countries of South Asia achieved significant control of the burden. In contrast, developed countries with a higher SDI have shown a notable increase in ASMR and age-standardized DALYs rate. Children and older adults have always been high-risk groups for encephalitis.

CONCLUSION

Although the global burden of encephalitis has decreased in the past 30 years, a further decline stopped from 2011-2013. The diverse burden in different regions calls for differentiated management, and the persistent high burden in some low-SDI regions and the increased burden in developed countries with higher SDIs deserve more attention.

ABBREVIATIONS

ASDR: age-standardized DALY rate, ASIR: age-standardized incidence rate, ASMR: age-standardized mortality rate, ASR: age-standardized rate, CI: confidence interval, DALY: disability-adjusted life-year, EAPC: estimated annual percentage change, GBD: Global Burden of Disease Study, HAP: household air pollution from solid fuels, HSE: herpes simplex encephalitis, HSV: herpes simplex virus, ICD: International Classification of Diseases, JE: Japanese encephalitis, PCR: polymerase chain reaction, SDI: socio-demographic index, TBE: tick-borne encephalitis, UI: uncertainty interval.

A Review of the Treatment of Herpes Simplex Virus-1 Encephalitis in Six Immunocompetent Patients

Introduction

The optimal treatment regimen for herpes simplex-1 (HSV-1) encephalitis is ill-defined. Current guidelines recommend the initiation of acyclovir in all suspected cases of encephalitis; however, there is limited research regarding the details of acyclovir treatment or the adjuvant use of corticosteroids. Specifically, there is a paucity of evidence-based guidelines detailing the optimal management of HSV-1 encephalitis in immunocompetent patients. In this study, we conducted a review of cases of immunocompetent patients with HSV-1 encephalitis to compare patterns in treatment and outcomes. 

Methods

A review of the literature was performed using PubMed using the terms herpes encephalitis, HSV, herpes zoster, and immunocompetent to identify cases of HSV-1 encephalitis in immunocompetent patients. The results were screened for cases describing the treatment regimen of HSV-1 encephalitis-positive, immunocompetent patients. 

Results

Six cases were identified. All six patients were treated with acyclovir with one patient receiving adjuvant corticosteroid therapy. Additionally, three patients were found to have acyclovir resistance and were transitioned to foscarnet. Eventually, one patient expired, two patients recovered with chronic morbidities of varying severity, and three patients made a full recovery. 

Discussion

Inconsistencies in the patient's disease course, therapeutic regimen, and comorbidities could all play a role in the varying case outcomes. While the optimal timing and composition of therapies in HSV-1 encephalitis in immunocompetent patients are still unclear, it seems the timely administration of antiviral treatment remains essential. Further research is needed to optimize HSV-1 encephalitis therapeutic regimens and improve patient outcomes. 

Burden of Tick-Borne Encephalitis, Sweden

In recent decades, the incidence of tick-borne encephalitis (TBE) in Sweden has increased. To calculate the burden of disease over a 17-year period, we analyzed data from the Swedish National Health Data Register for TBE cases diagnosed during 1998–2014. We compared healthcare use and sick leave associated with 2,429 persons with TBE with a referent cohort of 7,287 persons without TBE. Patients with TBE were hospitalized for significantly more days during the first year after disease onset (11.5 vs. 1.1 days), logged more specialist outpatient visits (3.6 vs. 1.2 visits), and logged more sick leave days (66 vs. 10.7 days). These differences generally increased over time. The case-fatality rate for TBE was 1.1%. Our calculated cost of TBE to society provides a baseline for decisions on immunization programs. Analyzing register data, our study adds to clinical studies of smaller cohorts and model-based studies that calculate disease burden.

Association between inflammatory central nervous system diseases and epilepsy: A retrospective cohort study of 4252 patients in Germany

GOAL

The goal of this study was to analyze the association between inflammatory central nervous system (CNS) diseases and the incidence of epilepsy in patients followed up for up to 10 years in Germany.

METHODS

This retrospective cohort study included adults aged ≥ 18 years who had an initial diagnosis of inflammatory CNS disease (i.e. encephalitis, meningitis or brain abscess) in one of 1229 general practices in Germany between 2005 and 2015 (index date). Patients without inflammatory CNS disease were matched (1:1) to those with inflammatory CNS disease by sex, age, follow-up time after index date, Charlson Comorbidity Index, and practice. The index date for patients without inflammatory CNS disease was a randomly selected visit date between 2005 and 2015. Kaplan-Meier curves and Cox regression analyses were used to assess the association between inflammatory CNS diseases and the incidence of epilepsy.

RESULTS

This study included 2126 individuals with and 2126 patients without inflammatory CNS disease (56.4% women; mean [SD] age 50.0 [12.3] years). Within ten years of the index date, 4.2% of patients with and 1.5% of patients without inflammatory CNS disease had been diagnosed with epilepsy (p < 0.001). This finding was corroborated in the Cox regression analysis, and there was a positive and significant association between inflammatory CNS diseases and epilepsy (HR: 3.82, 95% CI: 2.24-6.52).

CONCLUSIONS

Based on these results, preventive interventions are urgently warranted to reduce the incidence of epilepsy in individuals with a history of inflammatory CNS disease.

Health care resource utilization and treatment of leptomeningeal carcinomatosis in the United States

Background

The economic burden of cancer in the United States is substantial, and better understanding it is essential in informing health care policy and innovation. Leptomeningeal carcinomatosis (LC) represents a late complication of primary cancer spreading to the leptomeninges.

Methods

The IBM MarketScan Research databases were queried for adults diagnosed with LC from 2001 to 2015, secondary to 4 primary cancers (breast, lung, gastrointestinal, and melanoma). Health care resource utilization (HCRU) and treatment utilization were quantified at baseline (1-year pre-LC diagnosis) and 30, 90, and 365 days post-LC diagnosis.

Results

We identified 4961 cases of LC (46.3% breast cancer, 34.8% lung cancer, 13.5% gastrointestinal cancer, and 5.4% melanoma). The median age was 57.0 years, with 69.7% female and 31.1% residing in the South. Insurance status included commercial (71.1%), Medicare (19.8%), and Medicaid (9.1%). Median follow-up was 66.0 days (25th percentile: 24.0, 75th percentile: 186.0) and total cumulative costs were highest for the gastrointestinal subgroup ($167 768) and lowest for the lung cancer subgroup ($145 244). There was considerable variation in the 89.6% of patients who used adjunctive treatments at 1 year, including chemotherapy (64.3%), radiotherapy (57.6%), therapeutic lumbar puncture (31.5%), and Ommaya reservoir (14.5%). The main cost drivers at 1 year were chemotherapy ($62 026), radiation therapy ($37 076), and specialty drugs ($29 330). The prevalence of neurologic impairments was 46.9%, including radiculopathy (15.0%), paresthesia (12.3%), seizure episode/convulsive disorder not otherwise specified (11.0%), and ataxia (8.0%).

Conclusions

LC is a devastating condition with an overall poor prognosis. We present the largest study of LC in this real-world study, including current treatments, with an emphasis on HCRU. There is considerable variation in the treatment of LC and significant health care costs.