Clinical Epidemiology, Risk Factors, and Outcomes of Encephalitis in Older Adults.

BACKGROUND: Encephalitis is associated with significant morbidity and mortality, with unknown etiologies in the majority of patients. Large prognostic studies evaluating elderly patients are currently lacking. METHODS: We performed a retrospective cohort of encephalitis cases in 19 hospitals from New Orleans, Louisiana, and Houston, Texas, between the years 2000 and 2017. RESULTS: A total of 340 adult (aged ≥17 years) patients with confirmed encephalitis were enrolled, and 194 (57%) had unknown etiologies. A cerebrospinal fluid polymerase chain reaction (PCR) for herpes simplex virus (HSV) and varicella zoster virus was done in 237 (69%) and 82 (24%) patients, respectively. Furthermore, an arboviral serology was done in 169 (49%) patients and measurements of anti-N-methyl-D-aspartate receptor antibodies were taken in 49 (14%) patients. A total of 172 out of 323 patients (53%) had adverse clinical outcomes (ACOs) at discharge. Older individuals (>65 years of age) had a lower prevalence of human immunodeficiency virus, had a higher number of comorbidities, were less likely to receive adjuvant steroids, were more likely to have a positive arbovirus serology, were more likely to have a positive HSV PCR, were more likely to have abnormal computerized tomography findings, and were more likely to have to have an ACO (all P values < .05). Prognostic factors independently associated with an ACO were age ≥65, fever, Glasgow Coma Scale (GCS) score <13, and seizures (all P values ≤0.01). CONCLUSIONS: Encephalitis in adults remain with unknown etiologies and adverse clinical outcomes in the majority of patients. Independent prognostic factors include age ≥65 years, fever, GCS score <13, and seizures.

Clinical Characteristics and Predictors of Adverse Outcome in Adult and Pediatric Patients With Healthcare-Associated Ventriculitis and Meningitis.

Background. Healthcare-associated meningitis or ventriculitis is a serious and life-threatening complication of invasive neurosurgical procedures or penetrating head trauma. Methods. We performed a retrospective study of adults and children with the diagnosis of healthcare-associated meningitis or ventriculitis, as defined by the 2015 Centers of Disease Control and Prevention case definition, at 2 large tertiary care hospitals in Houston, Texas from July 2003 to November 2014. Patients were identified by infection control practitioners and by screening cerebrospinal fluid samples sent to the central laboratory. We collected data on demographics, clinical presentations, laboratory results, imaging studies, treatments, and outcomes. Results. A total of 215 patients were included (166 adults and 49 children). A positive cerebrospinal fluid culture was seen in 106 (49%) patients, with the majority of the etiologies being Staphylococcus and Gram-negative rods. An adverse clinical outcome was seen in 167 patients (77.7%) and was defined as death in 20 patients (9.3%), persistent vegetative state in 31 patients (14.4%), severe disability in 77 patients (35.8%), or moderate disability in 39 patients (18.1%). On logistic regression analysis, age >45 years (adjusted odds ratio [OR], 6.47; 95% confidence interval [CI], 2.31-18.11; P ≤ .001), abnormal neurological exam (adjusted OR, 3.04; 95% CI, 1.27-7.29; P = .013), and mechanical ventilation (adjusted OR, 5.34; 95% CI, 1.51-18.92; P = .01) were associated with an adverse outcome. Conclusions. Healthcare-associated meningitis or ventriculitis is associated with significant morbidity and mortality.

Epidemiology of bacterial meningitis in the USA from 1997 to 2010: a population-based observational study.

BACKGROUND: Bacterial meningitis continues to be a substantial cause of morbidity and mortality, but the epidemiological trends after adjunctive dexamethasone recommendations are unknown in the USA. We aimed to describe the changing patterns among the most common bacterial causes in the USA after conjugate vaccination and to assess the association between adjunctive dexamethasone and mortality. METHODS: For this population-based observational study, we searched information available from hospital discharges about incidence and inpatient mortality for the most important causes of community and nosocomial bacterial meningitis based on International Classification of Diseases coding across all hospitals in the USA between 1997 and 2010 with the HealthCare Cost Utilization Project (HCUP) network database. We calculated incidences according to US Census Bureau data and used a negative binomial regression model to evaluate the significance of changes over time. We assessed mortality from pneumococcus for three periods 1997-2001 (baseline), 2002-04 (transition years), and 2005-08 (after corticosteroid recommendations were available). FINDINGS: Streptococcus pneumoniae incidence fell from 0·8 per 100 000 people in 1997, to 0·3 per 100 000 people by the end of 2010 (RR 0·3737, 95% CI 0·1825-0·7656). Mortality from pneumococcal meningitis decreased between 2005 (0·049 per 100 000 people) and 2008 (0·024 per 100 000 people) compared with between 2002 (0·073 per 100 000 people) and 2004 (0·063 per 100 000 people; RR 0·5720, 95% CI 0·4303-0·7582). The incidence of Neisseria meningitidis infection decreased from 0·721 per 100 000 people in 1997, to 0·123 per 100 000 people in 2010 (RR 0·1386, 95% CI 0·048-0·4284), which has placed this pathogen close to common bacterial causes of nosocomial meningitis such as staphylococcus and Gram-negative bacteria and to Haemophilus influenzae. INTERPRETATION: S pneumoniae continues to be the leading identifiable cause of bacterial meningitis in the USA, but with a significant decrease in incidence and mortality associated with the introduction of conjugated vaccines and a mortality decrease that is associated with the introduction of recommendations for use of adjunctive dexamethasone for pneumococcal meningitis. FUNDING: National Center for Research Resources.